CSA
Recommendations
Read the report at California State Auditor ↗
Automated License
Plate Readers
To Better Protect Individuals’ Privacy, Law
Enforcement Must Increase Its Safeguards
for the Data It Collects
February 2020
REPORT 2019‑118
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CALIFORNIA STATE AUDITOR
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Elaine M. Howle State Auditor
February 13, 2020
2019-118
The Governor of California
President pro Tempore of the Senate
Speaker of the Assembly
State Capitol
Sacramento, California 95814
Dear Governor and Legislative Leaders:
As directed by the Joint Legislative Audit Committee, my office conducted an audit of local law
enforcement agencies’ use of automated license plate readers (ALPR); the following report details
the audit’s findings and conclusions. In general, we determined that the law enforcement agencies
we reviewed must better protect individuals’ privacy through ensuring that their policies reflect
state law. In addition, we found that these agencies must improve their ALPR data security,
make more informed decisions about sharing their ALPR data, and expand their oversight of
ALPR users.
We reviewed four agencies in detail that operate ALPR systems—Fresno Police Department,
Los Angeles Police Department, Marin County Sheriff’s Office, and Sacramento County Sheriff’s
Office. An ALPR system collects and stores license plate images of vehicles passing in its view
and enables law enforcement to track a vehicle’s movements over time; such a system raises
privacy concerns. State law helps address these concerns by requiring agencies to have policies
and safeguards in place to protect their ALPR systems from misuse. However, the agencies we
reviewed either did not have ALPR policies or their policies were deficient, and they had not
implemented sufficient safeguards. For example, none had audited searches of the ALPR images
by their staff and thus had no assurance that the searches were appropriate. Furthermore, three of
the four agencies have shared their ALPR images widely, without considering whether the entities
receiving them have a right to and need for the images. The statewide survey of law enforcement
agencies we conducted found that 70 percent operate or plan to operate an ALPR system, and this
raises concerns that these agencies may share the deficiencies we identified at the four agencies we
reviewed. Because many of the issues we identified link to the agencies’ deficient ALPR policies
we recommend that the Legislature direct the California Department of Justice to develop a
policy template that local law enforcement agencies can use as a model for their ALPR policies.
Our statewide survey also showed that the period of time law enforcement agencies retain ALPR
images varies widely. However, among the four agencies we reviewed none had considered the
usefulness of the ALPR images to investigators over time when determining their retention periods.
We recommend that the Legislature amend state law to specify a maximum retention period for
ALPR images.
Respectfully submitted,
ELAINE M. HOWLE, CPA
California State Auditor
621 Capitol Mall, Suite 1200 | Sacramento, CA 95814 | 916.445.0255 | 916.327.0019 fax | www.auditor.ca.gov
iv California State Auditor Report 2019-118
February 2020
Selected Abbreviations Used in This Report
ACLU American Civil Liberties Union
ALPR Automated license plate reader
CHP California Highway Patrol
CJIS Criminal Justice Information Services Division
CLETS California Law Enforcement Telecommunications System
FBI Federal Bureau of Investigation
GPS Global positioning system
ICE U.S. Immigration and Customs Enforcement
IT Information technology
OECD Organization for Economic Cooperation and Development
California State Auditor Report 2019-118 v
February 2020
Contents
Summary 1
Introduction 7
Audit Results
The Four Law Enforcement Agencies We Reviewed Have
Not Consistently Fulfilled Requirements Designed to
Protect Individuals’ Privacy 15
The Law Enforcement Agencies Have Often Placed Their
ALPR Data at Risk 18
The Law Enforcement Agencies Have Failed to Monitor Use of
Their ALPR Systems and Have Few Safeguards for Creating
ALPR User Accounts 32
Other Areas We Reviewed 39
Recommendations 40
Appendix A
Summary of ALPR Survey Responses 45
Appendix B
Scope and Methodology 49
Responses to the Audit
Department of Justice 53
Fresno Police Department 55
Los Angeles Police Department 59
California State Auditor’s Comments on the Response From
the Los Angeles Police Department 61
Marin County Sheriff’s Office 63
California State Auditor’s Comments on the Response From
the Marin County Sheriff’s Office 67
Sacramento County Department of Human Assistance 71
Sacramento County Sheriff’s Office 73
California State Auditor’s Comments on the Response From
the Sacramento County Sheriff’s Office 77
vi California State Auditor Report 2019-118
February 2020
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California State Auditor Report 2019-118 1
February 2020
Summary
Results in Brief Audit Highlights . . .
To better protect the privacy of residents, local law enforcement Our audit of the use of automated
agencies must improve their policies, procedures, and monitoring license plate readers (ALPR) at four local
for the use and retention of license plate images and corresponding law enforcement agencies highlighted
data. The majority of California law enforcement agencies (agencies) the following:
collect and use images captured by automated license plate reader
» Local law enforcement agencies did not
(ALPR) cameras. The ALPR system is both a real‑time tool for these
always follow practices that adequately
agencies and an archive of historical images. Fixed cameras mounted
consider the individual’s privacy in
to stationary objects, such as light poles, and mobile cameras
handling and retaining the ALPR images
mounted to law enforcement vehicles, capture ALPR images.
and associated data.
Software extracts the license plate number from the image and
stores it, with the date, time, and location of the scan and sometimes » All four agencies have accumulated
a partial image of the vehicle, in a searchable database. The software a large number of images in their
also automatically compares the plate number to stored lists of ALPR systems, yet most of the
vehicles of interest, called hot lists then issues alerts, called hits if images do not relate to their criminal
the plate number matches an entry on the hot list. Agencies compile investigations—99.9 percent of the
these hot lists based on vehicles sought in crime investigations 320 million images Los Angeles stores are
and vehicles connected to people of interest—for example, a list of for vehicles that were not on a hot list
stolen vehicles or of missing persons. We use the term ALPR data when the image was made.
to describe all the information stored in an ALPR system, including
• None of the agencies have an
license plate images and hot lists.
ALPR usage and privacy policy
that implements all the legally
Because an ALPR system stores the plate number and image in a
mandated—since 2016—
database even if the plate number does not match one on a hot list,
requirements.
the American Civil Liberties Union (ACLU) raised concerns in a
2013 report about law enforcement collecting and storing ALPR
• Three agencies did not completely or
images related to individuals not suspected of crimes. The ACLU
clearly specify who has system access,
noted that law enforcement officers could inappropriately monitor
who has system oversight, or how to
the movements of individuals such as ex‑spouses, neighbors, and
destroy ALPR data, and the remaining
other associates—actions that do not respect individuals’ privacy.
agency has not developed a policy
Although ALPR supporters contend that the images are collected in
at all.
public places where there is no reasonable expectation of privacy,
state law has made privacy a consideration when operating or using • Two of the agencies add and store
an ALPR system. Nonetheless, we found that the handling and names, addresses, dates of birth, and
retention of ALPR images and associated data did not always follow criminal charges to their systems—
practices that adequately consider an individual’s privacy. some of these data may be categorized
as criminal justice information
Although law enforcement agencies collect ALPR images in public and may originate from a system
view, and there is no reasonable expectation of privacy regarding maintained and protected by the
a license plate, the use and retention of those images raises Department of Justice.
privacy concerns. The four local law enforcement agencies we
reviewed—Fresno Police Department (Fresno), Los Angeles Police
Department (Los Angeles), Marin County Sheriff’s Office (Marin), continued on next page . . .
and Sacramento County Sheriff’s Office (Sacramento)—have
accumulated a large number of images in their ALPR systems, yet
most of these images are unrelated to their criminal investigations.
2 California State Auditor Report 2019-118
February 2020
• Three agencies use a cloud storage For example, at Los Angeles only 400,000 of the 320 million images
vendor to hold their many images and it has accumulated over several years and stores in its database
associated data, yet the agencies lack generated an immediate match against its hot lists. In other
contract guarantees that the cloud words, 99.9 percent of the ALPR images Los Angeles stores are for
vendor will appropriately protect vehicles that were not on a hot list at the time the image was made.
the data. Nevertheless, the stored images provide value beyond immediate
hit alerts, as law enforcement personnel can search the accumulated
• Three agencies share their images with
images to determine the vehicles present at particular locations and
hundreds of entities across the U.S. but
to track vehicles’ movements at particular times in order to gather
could not provide evidence that
or resolve leads in investigations.
they had determined whether those
entities have a right or a need to access
Technology gives governments the ability to accumulate volumes
the images.
of information about people, raising a reasonable question: How
» Agencies may be retaining the images is an individual’s privacy to be preserved? Effective in 2016 the
longer than necessary and thus California Legislature addressed privacy with respect to ALPR
increasing the risk to individuals’ privacy. systems through Senate Bill 34 (Statutes of 2015, Chapter 532)
(SB 34) by establishing requirements for these systems, including
» The agencies have few safeguards for
requiring detailed usage and privacy policies that describe the
creating ALPR user accounts and have not
system’s purpose, who may use it, how the agency will share data,
audited the use of their systems.
how the agency will protect and monitor the system, and how long
the agency will keep the data. Yet the agencies we reviewed have
not implemented all of the requirements in that law.
Law enforcement agencies must first create policies that set
clear guidelines for how they will use ALPR data. Setting certain
expectations in writing through an ALPR usage and privacy policy
helps ensure that agencies operate their ALPR programs in a
manner that better protects individuals’ privacy. However, none
of the four agencies have an ALPR policy that contains all of the
required information. In fact, Los Angeles has not developed an
ALPR policy at all. The other three agencies did not completely or
clearly specify who has system access, who has system oversight, or
how to destroy ALPR data. Their poorly developed and incomplete
policies contributed to the agencies’ failure to implement ALPR
programs that reflect the privacy principles in SB 34.
ALPR systems may contain data beyond license plate images. For
example, we found that Sacramento and Los Angeles are adding
names, addresses, dates of birth, and criminal charges to their
ALPR systems, which are then stored in those systems. Some of
these data may be categorized as criminal justice information;
in addition, the data may originate from the California Law
Enforcement Telecommunications System (CLETS), which the
California Department of Justice (Justice) maintains. These various
types of data require different levels of protection under the law.
State law requires these agencies to maintain reasonable security
procedures and practices to protect ALPR data from unauthorized
access, destruction, use, modification, or disclosure. In addition, we
believe that policy from the Criminal Justice Information Services
California State Auditor Report 2019-118 3
February 2020
Division (CJIS) of the U.S. Federal Bureau of Investigation (FBI)
models reasonable security measures for law enforcement agencies’
ALPR data. CJIS policy specifies operational, administrative,
technical, and physical safeguards for each of the areas specified in
state law.
Fresno, Marin, and Sacramento use a cloud storage solution to
hold their many ALPR images and associated data. Although the
three agencies told us their systems comply with CJIS policy, none
of them could demonstrate the vetting they performed to confirm
that their cloud storage vendor did, in fact, meet the CJIS policy
standards. Moreover, none of the contracts these three agencies
have with their cloud storage vendors include all necessary data
security safeguards. Thus, the agencies lack guarantees that the
cloud vendor will provide appropriate protection of their data.
Law enforcement agencies of all types may benefit from guidance
to improve their policies and data security practices. We surveyed
391 police and sheriff departments statewide, and of those using an
ALPR system, 96 percent stated that they have ALPR policies, and
nearly all reported that their ALPR data storage solution complies
with CJIS policy. However, it is likely that many of the survey
respondents have the same problems we identified at the four
agencies we visited. Justice has experience guiding law enforcement
agencies to help them adhere to state law and to improve their
administrative practices. By developing guidance for local agencies
on needed ALPR policy elements, Justice could help them improve
the quality and completeness of their policies.
State law allows law enforcement agencies to share ALPR images
only with public agencies, and it requires such sharing to be
consistent with respect for individuals’ privacy. Three of the
reviewed agencies share their ALPR images widely using features
in the ALPR systems that enable convenient sharing of images
with minimal effort. Fresno and Marin have each arranged to share
their ALPR images with hundreds of entities and Sacramento
with over a thousand entities across the United States. However,
we did not find evidence that the agencies had always determined
whether an entity receiving shared images had a right and a need to
access the images or even that the entity was a public agency. We
are concerned that unless an agency conducts verifying research,
it will not know who is actually using the ALPR images and for
what purpose.
In addition, the agencies have not based their decisions regarding
how long to retain their ALPR images on the documented
usefulness of those images to investigators, and they may be
retaining the images longer than necessary, increasing the risk to
individuals’ privacy. Fresno’s policy is to retain ALPR images for
4 California State Auditor Report 2019-118
February 2020
one year; Sacramento’s and Marin’s policies specify two years.
Los Angeles does not have an ALPR policy, and the lieutenant who
administers the ALPR program stated that its protocol is to retain
the images for at least five years. However, when we reviewed the
agencies’ ALPR searches over a six‑month period in 2019, we found
that personnel for three of the four agencies typically searched for
images zero to six months old. Nonetheless, the agencies keep the
images far longer.
The agencies we reviewed have few safeguards for the creation
of ALPR user accounts and have also failed to audit the use of
their ALPR systems. Instead of ensuring that only authorized
users access ALPR data for appropriate purposes, the agencies
have left their systems open to abuse by neglecting to institute
sufficient oversight. Over the years, the media has reported that
some individuals within law enforcement used or could use data
systems—and sometimes ALPR systems—to obtain information
about individuals for their personal use, including to locate places
they regularly visit, to determine their acquaintances, and to
blackmail them based on this information. ALPR systems should
be accessible only to employees who need the data, and accounts
should be promptly disabled otherwise. However, the agencies often
neglected to limit ALPR system access and have allowed accounts
that should be disabled to remain active longer than is prudent. To
further ensure that individuals with access do not misuse the ALPR
systems, the agencies should be auditing the license plate searches
that users perform, along with conducting other monitoring
activities. Instead, the agencies have conducted little to no auditing
and monitoring and thus have no assurance that misuse has
not occurred.
Recommendations
Legislature
To better protect individuals’ privacy and to help ensure that local
law enforcement agencies structure their ALPR programs in a
manner that supports accountability for proper database use, the
Legislature should amend state law to do the following:
• Require Justice to draft and make available on its website a policy
template that local law enforcement agencies can use as a model
for their ALPR policies.
California State Auditor Report 2019-118 5
February 2020
• Require Justice to develop and issue guidance to help local law
enforcement agencies identify and evaluate the types of data they
are currently storing in their ALPR systems. The guidance should
include the necessary security requirements agencies should
follow to protect the data in their ALPR systems.
• Establish a maximum data retention period for ALPR images.
• Specify how frequently ALPR system use must be audited and
that the audits must include assessing user searches.
Law Enforcement Agencies
To address the shortcomings this audit identified, Fresno,
Los Angeles, Marin, and Sacramento should do the following:
• Improve their ALPR policies.
• Implement needed ALPR data security.
• Update vendor contracts with necessary data safeguards.
• Ensure that sharing of ALPR images is done appropriately.
• Evaluate and reestablish data retention periods.
• Develop and implement procedures for granting and managing
user accounts.
• Develop and implement ALPR system oversight.
Agency Comments
The four law enforcement agencies we reviewed responded to
the draft audit report. Fresno responded that it will use the audit
to work to achieve its goal of building trust in its community.
Los Angeles responded that it respects individuals’ privacy
and believes it has policies in place to safeguard information.
Nonetheless, it is working on an ALPR policy as required by state
law and will perform periodic audits of users’ searches. Marin
stated it is committed to improvement and will consider the
recommendations we made, although it disagreed with several of
them. Sacramento stated that it had already begun implementing
many of the recommendations, but that it did not agree with how
we characterized some of the findings. Justice and the Sacramento
County Department of Human Assistance also responded
by acknowledging the draft report, although we did not have
recommendations directed to either entity.
6 California State Auditor Report 2019-118
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California State Auditor Report 2019-118 7
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Introduction
Background
An automated license plate reader (ALPR) is a camera that captures
color images of license plates within its field of view. Fixed cameras
are mounted on stationary objects, such as light poles, while mobile
cameras are mounted on moving objects, such as patrol cars.
Software extracts the license plate numbers from the images and
stores the images, plate numbers, and dates, times, and locations
of the image captures in a searchable database. An ALPR system
consists of the cameras, the software that reads and converts
images of license plates into data, and the searchable database
that stores the data. Although the primary focus of each image
is the license plate, the image may also show part of the vehicle
itself, including individuals within the vehicle, depending on the
camera’s position. ALPR technology has existed since the 1970s, yet
widespread adoption by U.S. law enforcement agencies began only
in the mid‑2000s. Law enforcement agencies generally view ALPR
technology as a valuable tool in achieving their missions.
We conducted a statewide survey of 391 police and sheriff
departments, and the survey confirmed that ALPR use is
widespread in California: 230 police and sheriff departments
currently use an ALPR system, and 36 plan to use one. Table 1
provides an overview of the ALPR systems of the four law
enforcement agencies we reviewed as part of this audit.
Table 1
ALPR Systems of Four Audited Law Enforcement Agencies
NUMBER OF
CAMERA SYSTEMS
NUMBER OF AGENCY DATE AGENCY BEGAN
LAW ENFORCEMENT PERSONNEL WITH ACCESS CURRENT USING CURRENT
AGENCY TO ALPR DATA FIXED MOBILE ALPR VENDOR ALPR VENDOR
Fresno 231 0 8 Vigilant Solutions, LLC 2016
Los Angeles 13,000 3 393 PIPS Technology* 2007
Marin 38 0 3 Vigilant Solutions, LLC 2010
Sacramento 539 33 27 Vigilant Solutions, LLC 2012
Source: Analysis of reports on ALPR systems as of 2019 and the agencies’ survey responses.
* Los Angeles uses PIPS Technology cameras and a user interface from Palantir Technologies, Inc.
8 California State Auditor Report 2019-118
February 2020
An ALPR system is both a real‑time tool for law enforcement
agencies and an archive of historical information. After the
ALPR system identifies a license plate number in an image, it
compares the plate number to stored lists of license plate numbers
from vehicles of interest, called hot lists. Figure 1 shows how an
ALPR system uses hot lists to search stored images. Local law
enforcement agencies create their own hot lists and also obtain
hot lists from state and federal agencies. For example, the California
Department of Justice (Justice) provides hot lists to local agencies
that include license plate numbers associated with missing
persons, gang members, and suspected terrorists. We use the
term ALPR data to describe all the information stored in an ALPR
system, including license plate images and hot lists. Regardless of
whether a license plate number matches a plate on a hot list (a hit),
an ALPR system stores the plate image in a database, creating a
searchable archive. Officers may search the database in various
ways. For example, they may search for a full license plate number
to locate a specific vehicle, search for a partial license plate number
to locate a group of vehicles, or search for all vehicles recorded at a
particular location at specific times.
Law enforcement agencies can share ALPR data with other public
agencies. In the ALPR systems we observed, the agency could
choose to share ALPR images only, to share hot lists only, or to
share both. Accessing ALPR images shared from other jurisdictions
enables agencies to search a broader area, such as across
county and state lines. In addition, even if an agency does not
operate ALPR cameras itself, it can, through sharing agreements,
access ALPR images other agencies collect. Our statewide survey
showed that among agencies that operate ALPR systems, roughly
84 percent share their images. Sharing hot lists also enables broader
search coverage. For example, an agency could share a hot list that
provides license plates linked to wanted individuals with other
entities in the region. These entities would then receive hit alerts if
their cameras detected those plates.
California State Auditor Report 2019-118 9
February 2020
Figure 1
How ALPR Systems Work
ALPR SYSTEM
IMAGE CAPTURED
ALPR 01
IMAGE
STORED
LAW ENFORCEMENT
HOT LIST
AGENCY COMPILES
STORED
HOT LIST
ALPR 01
IMAGE COMPARED
TO HOT LIST
IDENTIFIED AS A
WANTED VEHICLE
LAW ENFORCEMENT
ALERTED
Source: Analysis of David J. Roberts and Meghann Casanova, Automated License Plate Recognition Systems: Policy and Operational Guidance for Law
Enforcement, International Association of Chiefs of Police, Washington, D.C., 2012.
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ALPR Vendors Most Commonly Used in California
Law enforcement agencies typically contract with a third‑party
vendor for an ALPR system. In our statewide survey, most—
70 percent—of those that have an ALPR system reported using a
company called Vigilant Solutions, LLC (Vigilant). Figure A.1 in
Appendix A summarizes these responses. Three of the agencies we
reviewed—the Fresno Police Department (Fresno), Marin County
Sheriff’s Office (Marin), and Sacramento County Sheriff’s Office
(Sacramento)—contract with Vigilant. The Vigilant ALPR system
provides a user interface to search license plates and the option
to share ALPR images and hot lists with other agencies through
the Vigilant system. Fresno, Marin, and Sacramento all store their
ALPR images on Vigilant’s server, which is a cloud service, and
share their images with other agencies that subscribe to Vigilant’s
services. Roughly 22 percent of the survey respondents that have
ALPR systems use a company called PIPS Technology. One of the
agencies we audited in depth, the Los Angeles Police Department
(Los Angeles), purchased its cameras from PIPS Technology, but
it stores the images on its own server. Los Angeles uses a software
platform called Palantir for the user interface that allows for
searches of its ALPR images, and it shares its
ALPR images with other agencies in the region
that use the Palantir user interface.
Key Elements Law Enforcement Agencies Must
Include in Their ALPR Usage and Privacy Policy
• The authorized purpose for using the ALPR system and State Laws Governing ALPR Systems and Data
collecting, accessing, or using ALPR data. Sharing
• A description of the job title or other designation of
the employees and independent contractors who are With few exceptions, California law requires
authorized to use or access the ALPR system, or to collect public agencies that operate and use ALPR
ALPR data. systems to implement a usage and privacy
policy. The Legislature passed Senate Bill 34
• The training requirements for those employees and
(Statutes of 2015, Chapter 532) (SB 34), effective
independent contractors authorized to use or access the
January 1, 2016, to establish requirements
ALPR system, or to collect ALPR data.
regarding the operation and use of ALPR systems.
• A description of how the ALPR system will be monitored
This law generally requires public agencies,
to ensure the security of the information and compliance
including law enforcement agencies, that operate
with applicable privacy laws.
or use an ALPR system to maintain reasonable
• The purposes of, process for, and restrictions on the sale, security procedures and practices to protect ALPR
sharing, or transfer of ALPR data. data, to implement a usage and privacy policy, to
• The length of time ALPR data will be retained, and the make that policy available to the public, and to
process for determining if and when to destroy retained post that policy on its website should the agency
ALPR data. have one, among other provisions. The text box
describes required elements of an agency’s ALPR
Source: Analysis of state law.
usage and privacy policy.
California State Auditor Report 2019-118 11
February 2020
SB 34 does not specify retention periods for ALPR data, although
another state law limits the California Highway Patrol (CHP) to
retaining its ALPR images for no more than 60 days, unless those
images are being used for felony investigations or as evidence.
Agencies implementing ALPR programs after January 1, 2016,
must also provide an opportunity for public comment before
implementing the program.
In 2018 another state law took effect that limits the information
law enforcement agencies can share for immigration enforcement
purposes and requires Justice to issue guidance to state and local
law enforcement agencies regarding these limitations as they
apply to law enforcement databases. In October 2018 Justice
issued this guidance, which can also serve as best practices for
law enforcement agencies on how to lawfully share ALPR images.
The guidance encourages law enforcement agencies that maintain
databases to inquire about the purpose for which the other law
enforcement agency intends to use the information contained
in the database. If a law enforcement agency intends to use the
information for immigration enforcement purposes, Justice states
that law enforcement agencies should require, as a condition of
accessing the database, an agreement that stipulates that access will
be made only in cases involving individuals with criminal histories,
or for information regarding the immigration or citizenship status
of an individual. Beyond this guidance and the hot lists Justice
provides to local law enforcement agencies, as we describe earlier,
Justice plays no other role in ALPR programs.
State law requires law enforcement agencies to maintain reasonable
security procedures and practices to protect ALPR data from
unauthorized access, destruction, use, modification, or disclosure.
These requirements mean that ALPR data are sensitive. For
comparison purposes, the California Department of Technology
Office of Information Security defines sensitive data for state
agencies as information that requires special precautions to protect
it from unauthorized use, access, disclosure, modification, loss, or
deletion. In addition to ALPR images and hot lists, a law enforcement
agency can enter other information into its ALPR system, such as
personal information and criminal justice information. Personal
information is information that identifies or describes an individual,
including name or physical description. SB 34—whose purpose
was, in part, to institute reasonable privacy standards for the
operation of ALPR systems—requires that ALPR data be protected
with reasonable operational, administrative, technical, and
physical safeguards to ensure their confidentiality. Thus, personal
information in an ALPR system also requires appropriate and
reasonable safeguards. Criminal justice information, as defined by
the Criminal Justice Information Services Division (CJIS) of the
U.S. Federal Bureau of Investigation (FBI), refers to data necessary
12 California State Auditor Report 2019-118
February 2020
for law enforcement and civil agencies to perform their missions.
This includes information about vehicles associated with crimes,
when accompanied by personal information.
When CJIS provides criminal justice information to law
enforcement agencies, it requires those agencies to comply with a
minimum set of information technology (IT) security requirements
to protect the information, and these requirements can serve as
best practices for agencies to follow. Because an agency can enter
personal information and criminal justice information into its
ALPR system, either as part of a hot list or as a comment added as
part of a license plate search, all ALPR data are sensitive and require
appropriate safeguards.
Privacy Concerns Related to ALPR Systems
Although law enforcement agencies collect ALPR images in public
view, and there is no reasonable expectation of privacy regarding a
license plate, the use and retention of those images raises privacy
concerns. The agencies we reviewed accumulate a large number of
images in their ALPR systems. For example, Sacramento recorded
1.7 million images in one week, and Los Angeles currently has
more than 320 million images in its ALPR database that it has
accumulated over several years. The majority of these images do not
generate hit alerts. For example, data from the Los Angeles system
show that at the time of our review only 400,000 (0.1 percent)
of the 320 million images Los Angeles has stored generated an
immediate match against its hot lists for vehicles associated with
car thefts, felonies, or warrants. However, the stored images provide
value beyond immediate hit alerts, as law enforcement personnel
can search the accumulated images to target the whereabouts of
vehicles at particular times or locations. This storage, retention, and
searching of the images, although valuable to law enforcement, has
the potential to infringe on individuals’ privacy.
Organizations such as the American Civil Liberties Union (ACLU)
have criticized law enforcement agencies’ collection of ALPR
images because of the risks it poses to privacy. The ACLU stated
that increasing numbers of cameras, long data retention periods,
and sharing of ALPR images among law enforcement agencies allow
agencies to track individuals’ movements in detail, and it has voiced
concerns that such constant monitoring can inhibit the exercise of
free speech and association. The ACLU has also raised concerns
that law enforcement officers could inappropriately monitor the
movements of individuals such as ex‑spouses, neighbors, and other
associates. There have been occurrences of officers misusing law
enforcement databases like those that contain ALPR images. In
2016 the Associated Press conducted a review that found more than
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February 2020
325 instances between 2013 and 2015 in which law enforcement
officers who misused databases were fired, suspended, or resigned,
and more than 250 instances of reprimands or lesser discipline
related to such misuse. For example, the Associated Press reported
on a police sergeant in Ohio who pleaded guilty to stalking his
ex‑girlfriend after he searched law enforcement databases for
personal information about her and also the woman’s mother, her
close male friends, and students from a course she taught.
Law enforcement has recognized the privacy concerns posed by the
operation of ALPR systems, yet it has also pointed to the usefulness
of the systems. For example, the Police Executive Research Forum
(police research forum) and the Mesa Police Department (Mesa) in
Arizona conducted a study of the effectiveness of ALPR systems for
Mesa’s auto theft unit in 2011. They found that officers got nearly
three times as many stolen vehicle hits and made about twice as
many vehicle recoveries when using an ALPR system, compared to
officers performing manual license plate checks. Law enforcement
has also found ALPR systems useful for investigations. For example,
the assistant chief of the Minneapolis Police Department told
the police research forum in 2012 that the department located a
vehicle associated with a domestic kidnapping case by searching
ALPR images. With regard to the retention of ALPR images, the
International Association of Chiefs of Police (chiefs’ association)
acknowledged the tension between long retention periods and
privacy. The chiefs’ association noted that a reluctance to destroy
records may stem from investigators’ experience that seemingly
irrelevant or untimely information may acquire new significance as
an investigation brings further details to light. However, the chiefs’
association also recognized the privacy risks of ALPR images. In
a 2009 report, it stated that mobile ALPR cameras could record
license plate numbers of vehicles parked at addiction counseling
meetings, doctors’ offices, and staging areas for political protests.
The chiefs’ association argued that establishing policies regulating
ALPR programs could mitigate privacy concerns, and it produced a
report in 2012 offering guidance on developing such policies.
Federal Guidance on Privacy Protection
As far back as 1973, the federal government acknowledged
that individuals’ privacy needs to be protected from arbitrary
and abusive record‑keeping practices. The U.S. Department of
Health, Education, and Welfare, as it was then known, identified
principles for the fair collection, use, storage, and dissemination
of personal information by electronic information systems. Over
time the principles were adapted into information practices.
According to the U.S. Government Accountability Office, a revised
version of the information practices was published in 1980 by
14 California State Auditor Report 2019-118
February 2020
the Organization for Economic Cooperation and Development
(OECD)—an international organization that works with
governments, policymakers, and citizens on social, economic,
and environmental challenges—and with some variation, these
practices form the basis of privacy laws in the United States and
around the world. The OECD updated its eight information
practices in 2013, and California’s lawmakers included many of
these information practices in SB 34. For example, the OECD’s
information practices describe the importance of an organization
specifying the purposes for which it is collecting and using data;
keeping data reasonably safe from the risk of unauthorized access,
destruction, use, modification, and disclosure; being open about
policies involving data; and being accountable for complying with
the information practices.
The U.S. Supreme Court (court) has not directly decided a case
that we could find addressing ALPR images, although it has
decided cases involving other electronic surveillance. Because
license plates are in plain view, the collection of license plate
images by law enforcement is not a per se violation of the Fourth
Amendment’s prohibition against unreasonable searches and
seizures. However, the court has found that certain electronic
data that reveal individuals’ movements over an extended period
of time, if gathered, do at some point impinge on privacy. The
court has specifically addressed these issues with respect to the
use of global positioning system (GPS) data and cell‑site location
information, which is location information linked to cellphone use.
Cell‑site location information—similar to ALPR images—provides
data on an individual’s continuous movements over a potentially
unlimited period of time. In a 2018 case involving cell‑site location
information, the court stated that “[a] person does not surrender
all [privacy] protections by venturing into the public sphere.” The
court continued, “With access to [cell‑site location information],
the Government can now travel back in time to retrace a person’s
whereabouts,” and noted that the information was collected on
everyone, not only “persons who might happen to come under
investigation.” Thus, even though case law on electronic data that
enable tracking of individuals’ movements over an extended period
of time is still evolving, the court has recognized that privacy
implications exist for such data, which can include ALPR images.
California State Auditor Report 2019-118 15
February 2020
Audit Results
The Four Law Enforcement Agencies We Reviewed Have Not Consistently
Fulfilled Requirements Designed to Protect Individuals’ Privacy
California’s lawmakers drafted current ALPR law to institute
reasonable privacy standards for the operation of ALPR systems.
As we discuss in the Introduction, technology gives governments
the ability to accumulate significant amounts of information about
people, raising the question of how individuals’ privacy is to be
preserved, and the federal and state governments and courts have
issued laws and guidance—including, in the case of California,
SB 34—related to the use of such information.
Yet local law enforcement agencies—specifically the four agencies
we reviewed—have not done all they could to respect individuals’
privacy by incorporating the requirements and concepts in SB 34
into their operations. With few exceptions, SB 34 requires a public
agency that operates or uses an ALPR system to implement a usage
and privacy policy that describes how the system will be used and
monitored to ensure the security of the ALPR data accessed or used.
The agencies we reviewed have mature ALPR programs—they have
been using their current ALPR vendors since as far back as 2007.
However, as we discuss later, we found that the agencies have risked
individuals’ privacy by not making informed decisions about sharing
ALPR images with other entities, by not considering how they are
using ALPR data when determining how long to keep it, by following
poor practices for granting their staff access to the ALPR systems,
and by failing to audit system use.
State law requires law enforcement agencies to administer ALPR
programs in ways that respect individual’s privacy and protect ALPR
data. The law also requires the agencies to have a written usage and
privacy policy that sets forth how they will operate and use their
ALPR systems. These usage and privacy policies must include the
following elements:
• Authorized purposes for using the ALPR system and collecting
the data.
• A description of the job title or other designation of individuals
who are authorized to use or access the ALPR system.
• Training requirements for the authorized individuals who will use
or access the ALPR system.
• A description of how the agency will monitor the ALPR system to
ensure the security of the data and compliance with privacy laws.
16 California State Auditor Report 2019-118
February 2020
• The purpose of, process for, and restrictions on the sale, sharing,
or transfer of ALPR data.
• The length of time the ALPR data will be retained and the process
used to determine if and when to destroy retained ALPR data.
Agencies may expand on these required elements as needed
to ensure that their collection, use, maintenance, sharing, and
dissemination of ALPR data are consistent with respect for
individuals’ privacy.
None of the four agencies we reviewed have an ALPR policy that
contains all of the required information, thereby contributing to
the agencies’ failure to implement programs that reflect the privacy
principles in SB 34. Los Angeles has not developed an ALPR policy,
and the policies of the other three agencies are deficient in various
ways, as Figure 2 shows. For example, all have failed to fully address
how they will monitor system use to ensure compliance with
applicable privacy laws, which likely contributed to their failure to
institute regular audits of user searches. The agencies could have
avoided concerns such as those shown in Figure 2, which we describe
later in this report if they had developed more thorough policies.
Clear policies that define the purposes and procedures for monitoring
ALPR systems help agencies meet their goals.
Figure 2
The Agencies’ ALPR Policies Are Missing Required Key Elements for Respecting Individuals’ Privacy
FFRREESSNNOO LLOOSS AANNGGEELLEESS MMAARRIINN SSAACCRRAAMMEENNTTOO
MISSING MISSING MISSING MISSING
• Who has access AN ALPR • Who has access • Who has access
• How it will monitor • How it will monitor • How it will monitor
POLICY
• Data-sales restrictions • Process for data destruction • Data-sales restrictions
Source: State law and the agencies’ ALPR policies as well as interviews with the agencies’ management.
California State Auditor Report 2019-118 17
February 2020
As a result of our audit, each of the four agencies is making or
considering changes to its policies. The ALPR administrators at
Fresno, Marin, and Sacramento agreed that their policies did not
contain one or more elements required by state law. They also
explained that they did not include certain policy requirements
they believed did not apply to their use of ALPR data. For example,
Sacramento’s ALPR policy does not describe ALPR data‑selling
restrictions because, according to the ALPR administrator,
Sacramento does not currently sell ALPR data. However, because
their policies are incomplete and do not specify what personnel
cannot do when interacting with their ALPR systems, these Fresno, Marin, and Sacramento
three agencies left out critical guidance to staff and increased the have incomplete ALPR policies,
risk that staff would use the ALPR system inappropriately. The which increases the risk that
program administrators at Fresno, Marin, and Sacramento told staff will use the ALPR systems
us that they will consider changes to their policies subsequent inappropriately.
to our audit. Although the lieutenant who serves as Los Angeles’
program administrator initially believed that the agency’s many
IT policies covered the ALPR program, when we brought the
deficiencies in oversight to his attention, he acknowledged the need
for Los Angeles to have an ALPR policy and began drafting one in
October 2019.
We are concerned that the policy deficiencies we found are not
limited to the agencies we reviewed, and thus law enforcement
agencies of all types may benefit from guidance to improve their
policies. We surveyed 391 police and sheriff departments statewide
about their ALPR programs, and many stated that they have ALPR
policies and that these policies are publicly available. Because state
law requires each agency that operates or uses an ALPR system
to implement a usage and privacy policy, and to make the policy
available to the public in writing and post it conspicuously on the
agency’s website, we inquired about how agencies throughout the
State were adhering to these requirements. Of the law enforcement
agencies using an ALPR system, 96 percent responded that they
have ALPR policies. Of this group, at least 70 percent stated that
they have posted their policy to their website. A breakdown of the
law enforcement agencies’ responses to our survey can be found
at http://auditor.ca.gov/reports/2019‑118/supplemental.html.
However, we believe it is likely that many of the survey respondents
will have the same problems with the quality and completeness
of their policies as the four agencies we visited. As we discuss in
the Introduction, Justice has issued guidance to law enforcement
agencies to help them understand how to adhere to state law
regarding the sharing of information for immigration enforcement
purposes. Given Justice’s experience and broad reach in the
law enforcement community, developing guidance for local law
enforcement agencies on needed policy elements could improve the
quality and completeness of their policies.
18 California State Auditor Report 2019-118
February 2020
The Law Enforcement Agencies Have Often Placed Their ALPR Data
at Risk
Administering ALPR programs in ways that respect individuals’
privacy requires a thoughtful and considered approach to data
management that the agencies we reviewed have not always taken.
Specifically, three of the agencies have agreed to share their images
widely with little knowledge of the receiving entities and their
need for the images. Moreover, the agencies have not based their
decisions regarding retention of images on their actual usefulness
to investigators and may be retaining the images longer than
necessary, increasing the risk to individuals’ privacy.
The Agencies May Not Be Adequately Protecting Their Sensitive
ALPR Data
Law enforcement agency personnel can upload or enter sensitive
information into their ALPR systems, which may require specific
safeguards. As we discuss in the Introduction, this sensitive
information could include personal information and criminal
justice information. In addition, these data may originate from
the California Law Enforcement Telecommunications System
(CLETS)—a system that allows law enforcement agencies to obtain
information from federal and state databases, such as arrests and
fingerprint records from Justice. In reviewing multiple agencies’
ALPR policies, we found several that stated that their ALPR systems
Law enforcement users can upload may contain information obtained through CLETS. Additionally, in
personal information and criminal a security and compliance memorandum, Vigilant acknowledged
justice information into the Vigilant that law enforcement users can upload personal information and
system through hot lists and open criminal justice information into the Vigilant system through hot
text fields. lists and open text fields.
For example, in addition to license plate images, Sacramento and
Los Angeles add data to their systems such as criminal charges and
warrant information, in combination with personal information
such as names, addresses, dates of birth, and physical descriptions.
The added data can be in the form of hot lists that agencies use
to search for license plates of interest, as shown in Figure 1 in the
Introduction, or they can be data that are entered into open text
fields. By running an automated function each day, Sacramento
extracts information from several databases and uploads the
information as hot lists to its ALPR system. Los Angeles does
not create its own hot lists, but it regularly downloads hot lists
from Justice and the Los Angeles County Sheriff’s Department,
then uploads the hot lists to its ALPR system. Another way that
information in addition to license plate images gets into an ALPR
system is by users adding it to open text fields. Data entered into
open text fields are generally associated with license plate searches.
California State Auditor Report 2019-118 19
February 2020
When conducting a search, staff are prompted to enter a case
number and the purpose of the search, and they may do so by
typing in text. The ALPR systems store this open text in their audit
logs, which detail user activity and the reasons for the activity.
In contrast to Sacramento and Los Angeles, Marin and Fresno
occasionally upload hot lists into their ALPR systems. With regard
to open text fields, we reviewed the audit logs for Marin and
Fresno and did not find personal information in combination with
other sensitive information in the six months of search records
we studied. However, the possibility exists that law enforcement
personnel could enter sensitive information into open text fields
during ALPR searches.
When an IT system lacks sufficient security, the system is at When an IT system lacks sufficient
risk of misuse and data breaches. Systems containing personal security, the system is at risk of
information and criminal justice information must have adequate misuse and data breaches.
protections to assure individuals’ privacy. However, as discussed in
the Introduction, ALPR data can originate from different sources,
and the source of the information may drive some of the required
IT security protocols. On one hand, CJIS developed a policy that
dictates the minimum standards that law enforcement agencies
must follow to protect criminal justice information they obtain
from the FBI (CJIS policy). On the other hand, users of Justice’s
CLETS system must follow the protections outlined in the CLETS
Policies, Practices and Procedures document, which describes
formal security measures law enforcement agencies must follow
to access and protect CLETS information in addition to the CJIS
policy requirements.
Further, it can be difficult to know what protections to apply to
data from different sources. For example, an individual’s address
obtained by searching the Department of Motor Vehicles database
through CLETS would be subject to Justice’s data security
requirements, but the same information obtained from a local law
enforcement agency database would not. Moreover, the personal
information Los Angeles and Sacramento have entered into their
ALPR search records does not include its origin, making the
required level of protection unclear.
Given these issues and the need to identify a standard that can
be uniformly applied to ALPR data regardless of their source, we
believe that CJIS policy provides reasonable security measures
for law enforcement agencies to protect all of their ALPR data.
State law requires these agencies to maintain reasonable security
procedures and practices to protect ALPR information from
unauthorized access, destruction, use, modification, or disclosure.
CJIS policy specifies operational, administrative, technical, and
physical safeguards for each of these areas. For example, CJIS policy
20 California State Auditor Report 2019-118
February 2020
requires agencies to ensure that their sensitive data are encrypted,
and it limits physical access to specific personnel authorized to
access the data. Nearly all of the 230 agencies that reported using
ALPR systems in response to our statewide survey—including
Fresno, Los Angeles, Marin, and Sacramento—reported that their
ALPR data storage solution complies with CJIS policy.
We are concerned that the Nevertheless, we are concerned that the agencies using Vigilant
agencies using Vigilant may not be protecting their ALPR data in conformity with CJIS
may not be protecting their policy standards. Fresno, Marin, and Sacramento store their ALPR
ALPR data in conformity with data in Vigilant’s cloud database, and CJIS policy requires agencies
CJIS policy standards. to ensure that the cloud vendors that store and process their
criminal justice information comply with its security requirements.
Such requirements include controlling physical access to sensitive
data, encrypting the data, and conducting background checks and
training for employees with access to criminal justice information.
In addition, before providing sensitive data to a vendor, CJIS
requires law enforcement agencies to identify necessary
authentication and monitoring controls, such as two‑factor
authentication and activity logging. Because the Vigilant software
is by default accessible via the Internet, an officer may be able to
access it using his or her personal device. The ability to access
ALPR data in this manner bypasses the agencies’ network security
safeguards and violates CJIS policy requiring agencies to monitor
and control access to the data.
One way to prevent users from signing in to the Vigilant system
using personal devices would be to implement authentication
controls, such as two‑factor authentication. Two‑factor
authentication involves a second level of verification, such as a
passcode sent to a specific device, and allows agencies to require
that the passcode be sent only to department‑issued devices.
Although Vigilant offers two‑factor authentication, Marin, Fresno,
and Sacramento do not use it. CJIS policy requires two‑factor
authentication only for systems that directly access federal
systems. However, this requirement recognizes that two‑factor
authentication is more secure than a basic username and password
login for systems like Vigilant that are accessible over the Internet.
Thus, two‑factor authentication could serve as a best practice for
agencies to prevent inappropriate access to their ALPR systems.
In addition, monitoring the activity logs can alert program
administrators to unauthorized access of their ALPR systems. CJIS
policy requires agencies to monitor access to systems that contain
criminal justice information. Vigilant provides its clients with
logs of network addresses that have accessed their ALPR systems,
and although Marin’s ALPR program administrator stated that he
reviews these logs, administrators from Sacramento and Fresno
confirmed that they do not. Reviewing the logs of system access
California State Auditor Report 2019-118 21
February 2020
could help the agencies monitor access to their ALPR systems
and detect whether someone accesses the ALPR system from an
unrecognized network address.
When law enforcement agencies provide sensitive information
to ALPR vendors, their contracts should provide assurance that
the vendor will adequately protect that information. CJIS policy
recommends several provisions that law enforcement agencies
should consider including in their contracts to ensure that cloud
vendors adequately protect criminal justice information. For
example, a contract that protects a law enforcement agency’s
data would make clear that the agency owns the data it uploads
into the ALPR system, that the agency’s data will not be stored
outside of the United States or Canada, and that employees at the
cloud vendor who have access to unencrypted criminal justice
information will undergo training and background checks. Without
these contract provisions, agencies lack guarantees that the cloud
vendor will implement appropriate protections of their data.
We found that the three agencies storing ALPR data in Vigilant’s We found that the three agencies
cloud—Fresno, Marin, and Sacramento—do not have sufficient storing ALPR data in Vigilant’s
data security safeguards in their contracts. As Figure 3 shows, none cloud—Fresno, Marin, and
of the agencies’ contracts with Vigilant meet all of the CJIS data Sacramento—do not have
security requirements. For example, the agencies’ contracts do sufficient data security safeguards
not state that Vigilant will store their data in the United States or in their contracts.
Canada. Marin’s contract does not make clear that Marin owns the
data it adds to the ALPR system. It is important to note that Vigilant
claims to implement data security measures that comply with CJIS
policy. In a security and compliance memorandum, Vigilant lists
steps it takes to encrypt data that may contain criminal justice
information, as well as physical and network security safeguards
it has in place to prevent unauthorized access to its ALPR cloud.
We have no basis to dispute Vigilant’s claims, but without strong
contract provisions requiring CJIS safeguards, the three agencies
have no guarantee that Vigilant will protect their data. As CJIS
policy states, ambiguous contract terms can lead to controversy
over data privacy and ownership rights, whereas a contract that
clearly establishes data ownership acts as a foundation for trust that
the cloud vendor will protect the privacy of the agency’s data.
22 California State Auditor Report 2019-118
February 2020
Figure 3
The Agencies’ Existing Agreements With Vigilant Do Not Contain Adequate Data Security Measures
Agreement should
specify the following: FFRREESSNNOO MMAARRIINN SSAACCRRAAMMEENNTTOO
How data are stored
Who owns the data
Who can access the data
How data are protected
MISSING MISSING MISSING
3 of 4 4 of 4 2 of 4
• Data storage • Data storage • Data storage
• Data access • Data ownership • Data access
• Data protection • Data access
• Data protection
Source: Agencies’ agreements with Vigilant and CJIS policy requirements.
A lack of IT department involvement and outdated contracts likely
contributed to the data security weaknesses we observed. Fresno,
Marin, and Sacramento have IT units that administer their systems
and ensure compliance with Justice’s data security requirements.
However, at Fresno and Marin, the IT units are responsible for network
security and have little oversight of the ALPR systems’ data security.
According to Fresno’s IT manager, Fresno’s main IT unit does not
manage user accounts or monitor access to the ALPR system. Fresno
has an IT analyst separate from the main IT unit who currently helps
administer user accounts and provides technical support for the ALPR
system; however, his background is not in network security. A deputy
in Marin’s auto theft unit manages Marin’s entire ALPR system—
including user accounts and training. This arrangement is not ideal,
since individuals outside of an agency’s IT department may lack the
expertise necessary to implement adequate data security safeguards.
According to Sacramento’s ALPR administrator, Sacramento’s IT
unit recently assumed responsibility for the ALPR system, but before
about April 2019, an officer outside of the IT unit administered the
ALPR system.
In addition, with the exception of Sacramento, the agencies have
not updated their contract terms with Vigilant for several years. The
agencies’ contracts renew each year when the agencies pay a service
fee to Vigilant. As a result, Fresno has not updated its contract
for three years, and Marin for nine years. Sacramento updated
California State Auditor Report 2019-118 23
February 2020
its contract terms with Vigilant in September 2019, after using its
previous agreement for seven years. Agreements that are not kept
current may reflect outdated practices or omit needed assurances,
increasing the risk that data are not protected.
Los Angeles was not able to demonstrate that it has an agreement in Los Angeles was not able
place to protect its ALPR data from inappropriate access. Los Angeles to demonstrate that it has
stores its ALPR data in a city‑controlled data center rather than an agreement in place to
in a vendor cloud like the agencies that use Vigilant. Nevertheless, protect its ALPR data from
Los Angeles contracts with Palantir for IT support, and the FBI’s inappropriate access.
2017 audit of Los Angeles’ data security practices identified Palantir
as an entity with access to criminal justice information; thus we
expected Los Angeles’ agreement with Palantir to meet CJIS policy
requirements. CJIS policy requires agencies to enter into agreements
with vendors that access their criminal justice information. The
agreements are to include an FBI‑drafted security addendum that
outlines specific safeguards a vendor agrees to put in place to comply
with CJIS policy and an acknowledgment by the vendor of the great
harm that may arise from misusing sensitive data. However, in
response to our request for its agreement with Palantir, Los Angeles
produced two expired contracts and a 2018 commodities agreement
extending its licensing and support for Palantir software. None of
these documents contained the FBI‑drafted security addendum. Thus
Los Angeles was not able to demonstrate that its agreement with
Palantir contains appropriate data protections to ensure that Palantir
employees with access to Los Angeles’ ALPR data will not use the
data for unauthorized purposes.
The Agencies Have Not Made Informed ALPR Image‑Sharing Decisions
A significant feature of ALPR systems is their ability to share
information with users across other organizations. A variety of
requirements and guidance exist regarding how law enforcement
agencies should share ALPR data, including images. ALPR images
contain the date, time, and location of the scanned license plate and
largely relate to vehicles that are not linked to crimes. The risk that the
images will be misused rises as the images are more widely distributed,
and there are numerous examples of law enforcement officers misusing
their access to various databases. For example, an Associated Press
article from 2016 reported a case from the state of Georgia in which an
officer accepted a bribe to search for a woman’s license plate number to
see whether she was an undercover officer. Although such an example
of misconduct is not representative of all law enforcement personnel,
it illustrates the need for appropriate safeguards over law enforcement
tools. Once a license plate is tied to an individual’s identity, which is
easy for a law enforcement officer to do, ALPR images may make it
possible to track that individual’s movements.
24 California State Auditor Report 2019-118
February 2020
State law allows local law enforcement agencies to share ALPR images
only with public agencies and requires sharing to be consistent with
respect for individuals’ privacy. Further, guidance that Justice issued
in October 2018 addresses the agencies’ governance of databases in
relation to immigration enforcement, and this guidance provides a best
practice for sharing in general. In the guidance, Justice encourages law
enforcement agencies to inquire regarding the purpose for which an
agency seeking access to their database intends to use the information
and then, as a condition for accessing the database, to require
agreements ensuring appropriate use of the data if its purpose includes
immigration enforcement. The chiefs’ association also recommends that
law enforcement agencies maintain ALPR image‑sharing records that
include information on how the requester intends to use the images.
The four agencies we reviewed asserted that they share ALPR images
with others on the principle that these entities have a right and need
to know the information. Because following state law necessitates
establishing an agency’s identity, i.e., the right to know, and Justice’s
guidance suggests establishing the purpose, i.e., the need to know, for
which an agency intends to use the images, the agencies’ position seems
consistent with state law and Justice’s guidance.
However, we had difficulty determining whether the reviewed agencies
have actually made informed decisions about sharing their ALPR images.
Fresno and Marin have each approved sharing their ALPR images with
hundreds of entities, and Sacramento with over a thousand. Many
of these entities are within California, but they also span most of the
other 49 states. Figure 4 shows the entities’ locations, illustrating how
We could not always ascertain how widely distributed access to these ALPR images is. In addition, we could
the agencies determined whether not always ascertain how the agencies determined whether an entity
an entity receiving access to images receiving access to images had a right and need to access them or even
had a right and need to access them whether the entity was a public agency. We reviewed the lists of entities
or even whether the entity was a and found one that appeared to be a non‑public entity and others that
public agency. were unidentifiable because they were listed only by initials. For example,
Fresno, Marin, and Sacramento all approved an entity listed as the
Missouri Police Chiefs Association (Missouri Association); however, this
is not a public agency but rather a professional organization that provides
training opportunities and advocates for pro‑law enforcement legislation.
However, none of the agencies could demonstrate that they had
evaluated the Missouri Association before sharing images, nor could they
tell us why the Missouri Association had a right to those images. When
we inquired with Vigilant, an official explained that despite the name, it
is the Missouri State Highway Patrol—a law enforcement agency—that
uses the account. The lists contain many other entities whose identities
and law enforcement purposes are not immediately evident. Unless a
law enforcement agency verifies each entity’s identity and its right to
view the ALPR images, the agency cannot know who is actually using
them. Although the three agencies reviewed their sharing arrangements
to varying degrees during our audit, none could demonstrate that they
perform this kind of verification before sharing their ALPR images.
California State Auditor Report 2019-118 25
February 2020
Figure 4
Three Agencies Have Authorized Sharing With Entities Located in States
Across the Nation
SACRAMENTO
1,119
FRESNO
982
MARIN
554
Source: Analysis of data‑sharing reports from the Vigilant system.
Similarly, even when an entity is a verified public agency, it is
not always evident that agencies are making informed decisions
by establishing the entity’s need for the ALPR images. Fresno,
Marin, and Sacramento all authorized sharing with the Honolulu
Police Department, but given the distance between California and
Hawaii and the limited instances of cars traveling between the
two states, it is uncertain whether the Honolulu Police Department
has a persuasive need for these ALPR images. Fresno’s ALPR
administrator agreed that not a great deal of thought went into its
decision to share with the Honolulu Police Department, and he
believes that it probably authorized the share because the entity was
a law enforcement agency. In contrast, Marin’s ALPR administrator
believes that sharing ALPR images widely is important because the
more information available to law enforcement, the more successful
it can be in its mission. However, sharing decisions should also
consider the importance of protecting individuals’ privacy. Each
authorized share exposes the ALPR images to greater risk of misuse;
therefore, the agencies should approach each sharing request
individually based on the requester’s actual need for the images.
26 California State Auditor Report 2019-118
February 2020
The three agencies have also relied on features in Vigilant’s software
rather than establishing their own practices for sharing their ALPR
images. A sound approach to sharing would include establishing
each requesting entity’s need to know and right to know and keeping
records of the assessment and resulting decision. However, none of
these agencies maintain records outside of the Vigilant user interface
of when or why they agreed to share with particular entities, and
neither Marin nor Sacramento includes a process for approving
sharing requests in their ALPR policies as state law requires. Fresno
has outlined procedures that incorporate these elements, but it has
not followed them. Fresno’s ALPR administrator explained that its
procedures require more information than an entity requesting
a share provides in the Vigilant user interface, and there has
been frequent turnover in the position responsible for approving
sharing requests.
Current administrators at the three agencies have difficulty
understanding when and how sharing occurred because the
information the Vigilant user interface displays has changed over time.
The status of a sharing relationship in the Vigilant system depends on
whether the involved entities’ accounts are active or inactive. Active
entities have a current account with Vigilant while inactive entities
do not. An agency may agree to share with an active entity that later
becomes inactive. Images cannot be shared between active and
inactive entities. However, unless an agency deliberately removes a
sharing relationship with an inactive entity, that sharing relationship
remains and would become operational if an inactive entity decided
to renew its account with Vigilant and become active once more.
Previously, Vigilant had structured its user interface so that inactive
entities did not appear in the sharing report that shows a list of entities
with whom an agency had agreed to share. Recently, Vigilant changed
its interface to make inactive entities visible. Whether an entity is
active is not apparent from the sharing report alone.
A change in the vendor’s user This change in the user interface and the fact that agencies kept no
interface and not keeping records of records of the shares they have authorized made it difficult for ALPR
authorized shares made it difficult administrators at the agencies to know the status of current sharing
for ALPR administrators to track relationships. For example, in 2014 a prior ALPR administrator
current sharing relationships. for Marin had agreed to share images with three U.S. Immigration
and Customs Enforcement (ICE) agencies. In December 2018,
Marin’s current ALPR administrator used the Vigilant user interface
to review the sharing report and noted that the report included
no ICE agencies. However, when he reviewed the report again
in August 2019—at our request—three ICE agencies appeared
on the list. We discussed this discrepancy with Vigilant, which
explained that the three ICE agencies were currently inactive.
When Marin’s ALPR administrator reviewed the sharing report
in December 2018, inactive agencies did not appear on the report,
but Vigilant subsequently changed its user interface so that inactive
California State Auditor Report 2019-118 27
February 2020
agencies did appear. Although the ICE agencies could not access
Marin’s ALPR images because they were inactive, to effectively end
the share, Marin needed to remove the authorization for sharing
with the ICE agencies, which Marin has since done.
According to Marin’s ALPR administrator, it is now the
department’s position that it will not share images with ICE, but
if it had remained unaware that the sharing relationships existed
and the ICE agencies had become active again, it would have been
sharing its ALPR images with them without knowing it was doing
so. Had Marin kept its own records of the sharing to which it had
agreed, it would have been aware that it had agreed to share with
ICE in the past, and it would have been able to remove those shares
promptly. Sacramento had also authorized sharing to ICE agencies
in the past. When the current ALPR administrator reviewed the
list of entities with which it shared images with in response to our
audit, he removed those shares as well. In contrast, Fresno had
never authorized any sharing relationship with an ICE agency.
Although none of the agencies using Vigilant currently share
with ICE agencies, all three had authorized shares with entities
with border patrol duties. Despite not having implemented any
agreements related to this sharing since Justice issued its guidance in
October 2018, the three agencies were all sharing with the San Diego
Sector Border Patrol of U.S. Customs and Border Protection at the
start of our audit. During our audit, Sacramento removed the share
to this agency. Marin and Sacramento had also authorized sharing
with an agency listed as “California Border Patrol,” and although
Sacramento removed this share at the same time it removed the
shares to ICE, Marin continues to share with this entity. Fresno
continues to share with the Customs and Border Protection National
Targeting Center. Although Sacramento had also authorized a Justice’s guidelines for sharing data
share to this entity, it removed this share during our audit. All of are particularly relevant, yet Fresno,
these entities’ duties could potentially intersect with immigration Marin, and Sacramento were either
enforcement. Justice’s guidelines for sharing data are particularly unaware of these guidelines or had
relevant in these cases, yet the agencies were either unaware of these not implemented them for their
guidelines or had not implemented them for their ALPR systems. ALPR systems.
Of the four agencies we reviewed, only Fresno and Sacramento
share hot lists they create, and they do so through a more controlled
process than for sharing ALPR images. Vigilant’s user interface
enables hot‑list sharing in addition to sharing ALPR images. In
contrast to its wide sharing of ALPR images, Fresno shares the
hot lists it occasionally uploads with only three law enforcement
agencies in the nearby region. Sacramento has agreed to share
six hot lists with eight law enforcement agencies in California. With
each agency, Sacramento took the additional step of developing a
memorandum of understanding providing guidelines for sharing
the hot lists and the signature of the chief official at each agency.
28 California State Auditor Report 2019-118
February 2020
Although the memorandum does not specify which hot lists
Sacramento will share, it does provide a record of the entities
with which hot‑list sharing occurred, unlike its sharing of ALPR
images for which no independent records exist outside the Vigilant
user interface.
In contrast with the other reviewed agencies, Los Angeles has limited
its sharing of ALPR images to entities within a regional structure
established for its ALPR program through a federal grant that helped
fund its ALPR program. As Figure 5 shows, Los Angeles shares ALPR
images with 58 other law enforcement agencies in the region. It
does not have agreements to share its ALPR images with any federal
agencies, including ICE. According to the lieutenant who administers
the ALPR program, Los Angeles decided to share images only with
entities using the same software so that it could maintain greater
control over its ALPR images. It has a formal agreement with each
agency, which provides a record of its sharing decisions.
Figure 5
Los Angeles Shares Images With 58 Law Enforcement Agencies
SAN FERNANDO
THOUSAND BURBANK
OAKS
PASADENA
LOS ANGELES WEST COVINA POMONA
MALIBU SANTA MONICA
TORRANCE ANAHEIM
LONG BEACH
SANTA ANA
IRVINE
Source: Analysis of data‑sharing memorandums of agreement.
California State Auditor Report 2019-118 29
February 2020
The Agencies’ Image Retention Decisions Are Unrelated to How They Use
the Images
The four agencies we reviewed retain ALPR images for varying
periods of time. Our review determined that with the exception
of CHP, state law does not mandate a specific retention period
for ALPR images collected, accessed, or used by public agencies,
nor does state law delineate the factors public agencies should
use in determining those periods. Instead, state law requires that
public agencies other than CHP that use or operate ALPR systems
specify, in the agency’s usage and privacy policy, the length of
time ALPR data will be retained and the process that the agency
will use to determine if and when to destroy retained ALPR
data. Fresno’s policy is to retain ALPR images for a minimum
of one year, Sacramento’s policy is to retain ALPR images for a
minimum of two years, and Marin’s policy is to retain images for
two years. Although the agencies’ policies describe their retention
periods as minimums, in practice the agencies have configured
their ALPR systems to delete images older than their specified
retention periods. Fresno and Sacramento each download and
retain images for longer than their prescribed retention policies
if the images are relevant to investigations. Los Angeles does not
have an ALPR policy, but the lieutenant who administers the ALPR
program stated that it adheres to the city’s Administrative Code,
which requires data to be retained for a minimum of five years.
None of the agencies considered the images’ utility over time when None of the agencies considered
establishing their retention periods. Fresno based its ALPR image the images’ utility over time when
retention period on state law, which allows some cities to destroy establishing their retention periods.
certain video monitoring records after one year. Marin did not
cite state law in its policy; its former ALPR administrator stated
that when setting a two‑year retention period, he considered other
agencies’ retention periods and the retention requirements for
litigation related to investigations. Both Marin’s and Fresno’s ALPR
administrators stated that they were not aware of any studies of how
useful older images in their ALPR systems were to their personnel. In
its ALPR policy, Sacramento cited a general state law that prohibits
some cities from destroying records less than two years old. The
lieutenant who oversees Sacramento’s ALPR program acknowledged
that the agency has not conducted any statistical analysis to
determine how long it needs to retain ALPR images. However, he
stated that, although he was not involved in drafting the original
policy, two years made sense considering federal regulations, which
permit retention of criminal intelligence information for no longer
than five years. The lieutenant cited those federal regulations as a best
practice for retaining sensitive data, connecting the ALPR images to
a tenet of federal regulations that law enforcement agencies should
keep criminal intelligence information as long as it is useful, even
though ALPR data are not criminal intelligence.
30 California State Auditor Report 2019-118
February 2020
To develop a retention policy that better protects individuals’ privacy, an
agency might begin by considering the time period during which ALPR
data are most useful to law enforcement. To assess the usefulness of
these images over time, we reviewed the four agencies’ ALPR searches
over a six‑month period—between late January and September 2019,
depending on when we visited the agencies—and found that personnel
at three of the four agencies typically searched for ALPR images zero
to six months old. When searching ALPR systems, investigators can
enter search dates to target specific periods of interest. For example, on
March 29, 2019, a Sacramento investigator searched for ALPR images
from six days earlier—March 23—indicating that images less than
one week old were relevant to that search. As Table 2 shows, we found
that the searches agency personnel at the three agencies performed
infrequently included older images. In fact, when investigators at Fresno,
Marin, and Sacramento specified date ranges, most searches were of
ALPR images that were less than six months old. In contrast, Los Angeles
had a relatively even distribution of searches between those less than
one year and those more than one year old. The Vigilant system defaults
to showing the 50 most recent records when investigators do not specify
a search date range. We analyzed 46,000 records for searches that did not
specify a date range and found that investigators for Marin, Fresno, and
Sacramento frequently did not seek further than the 50 default records,
indicating that they generally were not interested in older ALPR images.
Table 2
The Agencies Usually Search for ALPR Images That Are Six Months Old or Less
PERCENTAGE OF SEARCHES FOR IMAGES OF A SPECIFIED AGE
TOTAL SEARCHES OVER
RETENTION 6‑MONTH PERIOD 6+ MONTHS TO MORE THAN
PERIOD ANALYZED 0 TO 6 MONTHS 1 YEAR 1+ TO 2 YEARS 2 YEARS
Fresno* 1 year 850 92% 6% 1% 1%
Los Angeles 5 years 28,874 42 8 29 21
Marin* 2 years 26 88 8 0 4
Sacramento* 2 years 4,262 84 4 11 1
Source: Analysis of search records from the agencies’ ALPR systems between late January and September 2019, depending on when we visited the agency.
* The percentage of searches listed in this table beyond an agency’s retention period are likely from their personnel searching data belonging to other
agencies with longer retention periods.
Other states have established retention periods that are generally shorter
than the lengths of time California’s local law enforcement agencies are
retaining ALPR images. The National Conference of State Legislatures
identified at least 13 states that mandate maximum ALPR image retention
periods. As the text box shows, these vary widely, from three minutes
in New Hampshire to three years in Florida. Nevertheless, the majority
of these states have retention periods that do not exceed six months.
California State Auditor Report 2019-118 31
February 2020
In contrast, 230 California agencies responding to
our survey reported that they use ALPR systems, ALPR Image Retention Periods for 13 States
and nearly 80 percent of these—180 agencies—stated
that they retain their ALPR images for more than New Hampshire 3 minutes
six months. About 20 of those agencies indicated that
Maine 21 days
they retain ALPR images for more than five years.
Minnesota 60 days
Figure A.2 in Appendix A summarizes these responses.
Montana 90 days
North Carolina 90 days
The length of time law enforcement agencies need to
retain ALPR images will vary depending on how they Tennessee 90 days
use the images. Narrow use—for one purpose only, Arkansas 150 days
such as locating stolen cars—could dictate a short Nebraska 180 days
retention window. Personnel we interviewed at each ‑‑‑‑‑‑‑‑‑ LONGER THAN SIX MONTHS ‑‑‑‑‑‑‑‑
of the four agencies stated that investigators rely
Utah 270 days
primarily on recent images to investigate some types
Colorado 365 days
of crimes, such as auto theft. In contrast, using ALPR
Vermont 540 days
images to solve complex crimes could necessitate a
Georgia 900 days
longer retention window. For example, first‑degree
murder can be prosecuted at any time; therefore, a Florida 3 years
homicide investigator may be able to use ALPR
Source: National Conference of State Legislatures, Automated
images of any age to help solve a case. The
License Plate Readers: State Statutes, March 15, 2019, and review
four agencies we reviewed have access to of the listed states’ ALPR laws and guidelines.
information they can use to evaluate whether their
Note: These states allow retention for longer periods for specific
ALPR retention periods are reasonable. Their reasons, such as data used in investigations.
systems record each time personnel search ALPR
images, and these search records show the date of
the search and the parameters used to narrow the
search, such as location, date, and time. Agency administrators can
analyze these activity logs to understand the images personnel are
searching for and their relative ages.
Marin and Sacramento have allowed expired hot lists to remain
in their ALPR systems for far longer than their specified retention
periods. Unlike ALPR images, hot lists cannot be automatically
deleted by the Vigilant system. Instead, the agencies define a period
after which the hot list becomes inactive—meaning the ALPR system
no longer generates alerts from the list—but the list remains stored
in Vigilant’s servers until the agency deletes it. We found that Marin
and Sacramento are retaining hot lists longer than necessary because
their administrators were unaware of the need to manually delete
them. They assumed that their Vigilant system would automatically
delete inactive hot lists according to the designated purge schedule,
as it does ALPR images. For example, Marin retained an inactive
hot list of sex offenders for five years—three years longer than its
two‑year retention period for ALPR images. Sacramento has retained
multiple hot lists for as long as six years—four years longer than its
retention period for ALPR images. The types of lists ranged from a
hot list of Sacramento County sex offenders to a warrants hot list.
When we brought the inactive hot lists to the agencies’ attention,
32 California State Auditor Report 2019-118
February 2020
the administrators at Marin and Sacramento acknowledged that the
age of the hot lists exceeded the agency’s retention period, and they
were willing to delete the hot lists.
Law enforcement agencies should consider both the usefulness of
the ALPR images and individuals’ privacy when deciding how long
to retain the images. Cost, however, is not a factor. According to the
lieutenant who oversees Los Angeles’ ALPR program, the images
are useful to investigators and the cost of storing ALPR images
is not a significant factor in determining how long to store them.
Nevertheless, two studies by a consultant to the National Institute of
Justice and the chiefs’ association concluded that law enforcement
agencies must consider the trade‑offs between privacy concerns and
the utility of retaining the ALPR images they capture and store.
The Law Enforcement Agencies Have Failed to Monitor Use of Their ALPR
Systems and Have Few Safeguards for Creating ALPR User Accounts
Instead of ensuring that only authorized users access their ALPR data
for appropriate purposes, the agencies we reviewed have made abuse
possible by neglecting to institute sufficient monitoring. ALPR
systems should be accessible only to employees who need the data
and who have been trained in using the system. However,
the agencies often neglected to limit ALPR system access, to provide
appropriate training to individuals with access, or to monitor
accounts. Similarly, to ensure that individuals with access do not
misuse the system, the agencies should audit the license plate
searches users perform. Instead, the agencies conduct little to no
auditing and thus have no assurance that misuse has not occurred.
The Agencies Need Stronger User‑Access Safeguards
Best Practice Safeguards for Establishing and
Managing User Accounts
The four agencies we reviewed all failed to follow
Account Setup one or more best practices related to user access.
• Supervisor approval is a prerequisite for account access. State law requires agencies to maintain reasonable
security procedures and practices to protect
• ALPR training is a prerequisite for account access.
ALPR data from unauthorized access, and the
text box lists five best practices for user access,
Account Maintenance
from initiating an account to disabling it when
• Accounts defined as inactive are suspended.
an employee separates from the agency. Figure 6
• ALPR training is required for users linked to inactive shows the four agencies’ status in implementing
accounts to regain active status.
these best practices. Each ALPR administrator
• Accounts are deleted when employees separate stressed the concept of “need to know, right to
from the agency. know” as a key for data security; however, no
agency followed all of the best practices that
Source: CJIS policy and the State Administrative Manual.
would help establish the need to know and right to
know. For example, no agency had a requirement
California State Auditor Report 2019-118 33
February 2020
• Who has access • Who has access • Who has access
• How it will monitor • How it will monitor • How it will monitor
• Which restrictions exist • Process for data destruction • Which restrictions exist
on data sales on data sales
that supervisors approve staff requests for creating ALPR user
accounts. Such a step would provide assurance that the staff
member receiving the account had both a need and a right to access
the information in the ALPR system. Los Angeles is particularly
lax in this area because the protocol of its IT division is to include
its ALPR software on each computer it assigns to staff, regardless
of their position. Thus, staff who do not perform functions related
to the ALPR system nevertheless have access to the system. In
contrast, Sacramento follows all but one of the best practices listed
in the text box. In doing so, it requires staff to prove their initial and
continued need for ALPR data, among other access requirements.
Figure 6
The Agencies Lack Many Best Practice Safeguards for Establishing and Managing User Accounts
FFRREESSNNOO LLOOSS AANNGGEELLEESS MMAARRIINN SSAACCRRAAMMEENNTTOO
LACKS LACKS LACKS LACKS
4 of 5 4 of 5 2 of 5 1 of 5
SAFEGUARDS SAFEGUARDS SAFEGUARDS SAFEGUARDS
2 ACCOUNT SETUP
SAFEGUARDS
• Supervisor approval • Supervisor approval • Supervisor approval • Supervisor approval
What’s missing
• Training • Training
3 ACCOUNT
MAINTENANCE
SAFEGUARDS • Training to • Inactive accounts • Training to
What’s missing reactivate account suspended reactivate account
• Accounts disabled for • Training to
separated employees reactivate account
Source: Agencies’ policies, applicable procedures and protocols, and interviews with the agencies’ management.
Agencies could reduce instances of unnecessary access by ensuring
that only those staff whose current work assignments require access
to ALPR data have that access. The ALPR administrators at Marin
and Los Angeles believe that supervisory approval is unnecessary
34 California State Auditor Report 2019-118
February 2020
because ALPR users are already privy to data they consider more
confidential than ALPR data, such as criminal justice information.
However, these views do not consider that ALPR systems capture
images indiscriminately, irrespective of the criminal history of the
individual who is driving the vehicle, and the images allow law
enforcement to track individuals. Given that agencies retain these
images for several months or years, a user could combine them with
personal information from separate data sources to produce a great
number of details about someone’s life, such as his or her political or
religious affiliation. Without proper safeguards, staff could conduct
this form of surveillance on any driver. In fact, the chiefs’ association
Limiting ALPR access to employees acknowledged this possibility and warned that increasing ALPR
with the needs and the rights to use and data sharing would enhance the potential for surveillance.
access these data is a good step Thus, as the chiefs’ association concluded, limiting ALPR access to
toward protecting the individuals employees with the needs and the rights to access these data is a
whose privacy would be violated if good step toward protecting the individuals whose privacy would be
the data were misused. violated if the data were misused.
Ensuring that ALPR users are properly trained is another weakness
among the agencies we reviewed. Three of the agencies do not
ensure that all of their ALPR users are properly trained. The chiefs’
association called the training of authorized ALPR users “a critical
accountability measure.” However, as Figure 6 shows, neither Fresno
nor Los Angeles requires all ALPR users to complete ALPR training
before initially obtaining system access. Although Los Angeles offers
ALPR training, the detective who conducts this training confirmed
that it is not required before users can access the ALPR system.
Fresno’s policy encourages such training; however, its ALPR
administrator confirmed that the agency does not provide training
to all of its users. Further, Marin’s ALPR administrator stated that
although Marin provides training when staff first receive access to the
ALPR system, it does not require staff to renew their training in order
to reactivate their accounts following long periods of not using the
system. Without sufficient training, there is little assurance that ALPR
users know and understand agency ALPR policies, including recent
changes, or are aware of the limits on how they may use ALPR data.
Although the Fresno ALPR administrator agrees that the agency’s
safeguards surrounding user access are currently inadequate and
plans to improve them, the ALPR administrators at Los Angeles,
Marin, and Sacramento believe their current practices are acceptable.
The administrators at Marin and Los Angeles are reluctant to alter
their agencies’ existing practices because they believe ALPR data
are not as sensitive as other law enforcement data. We disagree
with these views because, as we mention previously, ALPR data are
sensitive and state laws require reasonable security procedures and
practices to protect them. A basic protection for data that must be
treated as sensitive is to limit who can access them.
California State Auditor Report 2019-118 35
February 2020
In addition, as we mention earlier, the ALPR images law
enforcement agencies collect largely involve vehicles that are
not associated with crimes, and if the images were analyzed,
the data could reveal behavior patterns and preferences that law
enforcement could use to conduct surveillance on individuals.
For example, according to a 2012 newspaper article, the New York
Police Department collected license plate numbers of vehicles
parked near a mosque. The department was purportedly trying to
identify terrorist activities. Although the department justified this
data collection as part of its strategy to identify potential criminal
activities, it targeted mosques and collected license plate numbers
at times without any leads or proof of terrorist connections. Given
the sensitivity of the information collected in this example, access
safeguards would ensure that only those staff who have a need and
right to access an ALPR system would possess that privilege.
Law enforcement agencies could further improve safeguards by
disabling employees’ accounts once they separate or after long
periods of nonuse. We reviewed Marin’s and Sacramento’s processes
for disabling accounts of separated employees. Both agencies follow
a similar approach, relying on one part of the organization providing
information to another. Sacramento produces a personnel transfer
and separation list every two weeks, and the IT security group uses
it to identify accounts to close. Although the IT security group
generally disabled accounts promptly after receiving the list, we found
that the contents of the list were not always current. For example, in
one instance, a separated employee did not appear on the list until
46 days after his separation date in June 2019. According to a human
resources specialist, employees submit their resignation paperwork
late at times, which causes human resources to not process this
paperwork until after an employee has left the department. Marin’s
ALPR administrator said that he removes ALPR accounts once he
receives a department‑wide email notifying him of an employee’s
resignation or termination. He also stated that he checks ALPR
accounts every few months to verify that active accounts match
active employees. However, for one employee, the administrator The fact that Marin and Sacramento
did not disable his ALPR access until two months after he resigned did not disable some accounts as
in October 2019. In fact, the administrator did not disable this necessary is problematic because
employee’s access until our office pointed out that the account was the former employees could log
still active. The fact that Marin and Sacramento did not disable into their accounts and access
some accounts as necessary is problematic because the former ALPR data from the web‑based
employees could log into their accounts and access ALPR data from version of the ALPR systems on any
the web‑based version of the ALPR systems on any Internet‑capable Internet‑capable device, not just
device, not just office devices. office devices.
With regard to Los Angeles and Fresno, Los Angeles’ network
manager described an automated process for deleting accounts
linked to overall network access, which reasonably aligned with
best practices. Conversely, Fresno’s ALPR administrator said that
36 California State Auditor Report 2019-118
February 2020
he periodically reviews the names of employees with user accounts
but started doing so only in September 2019 when he learned
of our audit. We did not test deleted accounts at either agency.
Deleting accounts prevents separated employees from continuing to
access ALPR data and is thus critical to protecting ALPR data and
individuals’ privacy.
The Agencies Have Failed to Audit ALPR Users’ Searches to Ensure That
Individuals’ Privacy Is Protected
State law requires law enforcement agencies that operate, access,
or use ALPR systems to protect their ALPR data—including
ALPR images—from unauthorized access, destruction, use,
modification, or disclosure. The law specifically requires them to
describe and implement a policy detailing how they will monitor
their ALPR systems. According to state law, agencies that access
or use ALPR systems must also conduct periodic system audits.
In its reports on managing ALPR systems, the chiefs’ association
stated that conducting audits aids in discouraging unnecessary or
inappropriate use of the data; in addition, when agency policies
include a strong auditing requirement, this reassures the public that
their privacy interests are recognized and respected.
A primary form of auditing to prevent misuse is reviewing the
searches users conduct in the ALPR systems. Users conduct
Even though law enforcement searches for specific license plates. Even though law enforcement
agencies that use or access ALPR agencies that use or access ALPR systems can monitor searches
systems can monitor searches simply by reviewing search records for red flags, such as an
simply by reviewing search records unknown user account, they should also conduct audits as
for red flags, they should also required by state law. An audit entails a more rigorous approach,
conduct audits as required by including evaluating risk and randomly selecting test items for
state law. review. Developing an audit of license plate searches, for example,
would involve determining how many searches to review, how to
select test items, and how frequently to conduct the audit. Law
enforcement agencies have often found evidence of misuse of their
databases, showing the need for auditing. For example, a news
article reported that CHP investigated 11 cases of database misuse
in 2018, including three involving officers improperly looking up
information on license plates through CLETS without a need to
know the information. The large datasets of ALPR images, dating
back at least one year, that the four reviewed agencies maintain
can be analyzed to reveal the daily patterns of vehicles that can be
linked to individuals and their activities—most of whom have not
engaged in criminal activity. A member of law enforcement could
misuse ALPR images to stalk an individual or observe vehicles at
particular locations and events, such as doctors’ offices or clinics
and political rallies. Despite these risks, the agencies we reviewed
conduct little to no auditing of users’ searches.
California State Auditor Report 2019-118 37
February 2020
We asked key officials at the three agencies using the Vigilant
system why they had not audited the searches users performed and
found that either they were unaware of the auditing requirement
in state law or the auditing they did conduct did not include user
searches. Fresno’s policy states that it should conduct audits on a
regular basis, but the ALPR administrator told us he believed audits
are the responsibility of the Audits and Inspections Division within
the department. However, the sergeant responsible for audits and
inspections—who took charge in January 2018—responded that
he was not aware of the requirement until our audit. Similarly, the
Marin ALPR administrator was unaware of the state law requiring
audits of ALPR systems until our audit and thus had not been
conducting them. At Sacramento, the policy states that the ALPR
administrator will conduct periodic audits of user searches. Even
though Sacramento administrators had been monitoring some
system functions, they had not audited searches of the older ALPR
images. The officer administering the ALPR program until April 2019
said that she did not conduct these audits because her predecessor
had not informed her that it was necessary. The ALPR program
transferred to a new division in April, and according to the current
ALPR administrator, limited staff resources have prevented him from
instituting these audits.
Although the agencies have not been conducting audits, we
considered the possibility that an agency employee or member
of the public may have reported instances of ALPR misuse. We
searched each agency’s records of internal affairs investigations
from January 1, 2016, to the present for cases involving ALPR
misuse and did not find any such cases. However, we do not
consider this proof that no instances of ALPR misuse occurred.
Given that the agencies were not regularly auditing their
systems, ALPR misuse may have occurred and gone unnoticed
and unreported.
To engage in meaningful auditing of their system users, all All four agencies must address
four agencies need to address the quality of the information users the quality of information they
enter into the system as part of their searches. Before allowing will need to audit user searches.
users to conduct searches, Fresno, Los Angeles, and Marin require In Sacramento, for 66 percent of
users to enter case numbers and reasons for the search; however, searches, users left case number
this is not happening consistently. We reviewed six months of user and search reason fields blank.
queries at the three agencies and found that users entered a wide
variety of information in the case number field. For example, users
at Los Angeles simply entered “investigation” into this field as well
as descriptions of vehicles and actual case numbers. In contrast,
Sacramento does not require users to enter either case numbers
or reasons. Our review showed that in 66 percent of searches,
Sacramento’s users left both fields blank. When users fail to enter any
information or fail to include appropriate detail, identifying misuse
through audits becomes nearly impossible.
38 California State Auditor Report 2019-118
February 2020
Los Angeles faces additional hurdles in performing meaningful
auditing because its ALPR administrators do not have immediate
access to data on user searches. Instead, according to the chief data
officer, administrators need to request that a software engineer
from Los Angeles’ ALPR software contractor build and run a query
in the system to obtain these data. In 2015 Los Angeles recognized
a need to fix this software limitation to enable administrators to
audit user searches. The chief data officer for Los Angeles stated
that, although an initial upgrade provided an audit dashboard
tool for administrators, subsequent software upgrades made this
tool unusable, and the company that provides the software is
developing a new one. He said that it is Los Angeles’ goal to have a
new audit dashboard tool by the end of the first quarter of 2020, at
which point he will work with the appropriate division within the
department to develop an audit plan. Although we agree that an
audit tool will facilitate audits, we believe it was entirely possible for
Los Angeles to obtain the data on user searches, and thus it could
have implemented a process for periodic system audits as state law
requires, despite the difficulties.
Fresno, Marin, and Sacramento The other three agencies also do not have an adequate policy or
do not have adequate policies or process in place for conducting meaningful audits. For example,
processes in place for conducting Fresno’s ALPR policy states that it should conduct periodic audits,
meaningful audits. but its policy does not specify how frequently it will audit its
ALPR system, who will perform those audits, who will review and
approve the audit results, and how long it will retain the audit
documents. Specifics such as these provide a clear road map for
planning, conducting, documenting, and resolving audits. When
followed, the agencies will have records demonstrating their
necessary oversight. Marin’s latest policy—dated July 2019—also
fails to cover these necessary details. Fresno and Marin began
reviewing user queries subsequent to the beginning of our
audit, but in the absence of an adequate policy or formal plan,
their methodologies are lacking. For example, although Fresno
began conducting audits that included a random sample of user
searches, staff have not developed a formal plan and provided us
only with handwritten notes on their methodology. Marin’s ALPR
administrator has not instituted audits and is simply monitoring
license plate searches by looking for instances in which the user did
not enter a reason for the search or entered a reason that does not
make sense, such as an investigation that does not exist. In addition,
at both Fresno and Marin, the individual conducting the audits or
monitoring is also a system user, creating a conflict when acting as
a system monitor or auditor. Without sound methodologies, the
agencies cannot be confident that they have sufficient protocols in
place to detect misuse.
California State Auditor Report 2019-118 39
February 2020
Other Areas We Reviewed
To address all the audit objectives approved by the Joint Legislative
Audit Committee (Audit Committee), we reviewed two additional
subject areas: whether the agencies offered opportunities for
the public to comment on their ALPR programs and whether
the Sacramento County Department of Human Assistance
(Human Assistance) continues to operate an ALPR program.
Three Agencies Provided Information to the Public on Their
ALPR Programs
State law requires that public agencies implementing ALPR
programs after January 1, 2016, offer an opportunity for the public
to comment about those programs. These opportunities increase
public awareness that law enforcement agencies are using electronic
means to collect information about vehicles in the community and
offer a way for the public to provide feedback about the programs.
The four agencies we reviewed began using ALPR before 2016
and consequently were not required to offer an opportunity for
public comments. Nonetheless, three of the agencies took some
steps to communicate with the public about their ALPR programs.
Los Angeles and Sacramento published documents describing
their ALPR programs, and at a Fresno City Council meeting, the
public had an opportunity to comment on the selected ALPR
vendor before the council voted on a new contract. The minutes
from that meeting reflect that the public made no comments. This
transparency helps foster public trust in law enforcement and
government as a whole.
Human Assistance No Longer Operates an ALPR Program
Our audit scope included reviewing the ALPR program of Human
Assistance, which provides Sacramento County residents with
employment assistance and supportive services. Human Assistance
contracted with Vigilant for three years to access ALPR images.
Human Assistance did not operate its own cameras, and it used
the ALPR images to investigate welfare fraud. According to the
administrator of its ALPR program, Human Assistance ended its
program in 2018 after determining that investigative staff rarely
searched the images, so the program could not justify the cost.
On November 1, 2018, Human Assistance deleted its ALPR user
accounts, leaving the administrator’s account active for internal
review. On May 31, 2019, Human Assistance’s ALPR agreement
with Vigilant expired, and the administrator no longer has access
to the account. Therefore, we did not perform any additional audit
work pertaining to Human Assistance.
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Recommendations
Legislature
• To better protect individual’s privacy and to help ensure that
local law enforcement agencies structure their ALPR programs
in a manner that supports accountability for proper database use,
the Legislature should amend state law to do the following:
‑ Require Justice to draft and make available on its website a
policy template that local law enforcement agencies can use as
a model for their ALPR policies.
‑ Require Justice to develop and issue guidance to help local law
enforcement agencies identify and evaluate the types of data
they are currently storing in their ALPR systems. The guidance
should include the necessary security requirements agencies
should follow to protect the data in their ALPR systems.
‑ Establish a maximum data retention period for ALPR images.
The Legislature should also establish a maximum data
retention period for data or lists, such as hot lists, that are
used to link persons of interest with license plate images.
‑ Require periodic evaluation of a retention period for ALPR
images to ensure that the period is as short as practicable.
‑ Specify how frequently ALPR system use must be audited and
that the audits must include assessing user searches.
‑ Specify that those with access to ALPR systems must receive
data privacy and data security training. The Legislature should
require law enforcement agencies to include training on the
appropriateness of including certain data in an ALPR system,
such as data from CLETS.
Law Enforcement Agencies
• To ensure that their ALPR policies contain all of the required
elements as specified in state law, by August 2020, Fresno,
Los Angeles, Marin, and Sacramento should review their policies
and draft or revise them as necessary. Also by August 2020 these
agencies should post their revised policies on their websites in
accordance with state law.
California State Auditor Report 2019-118 41
February 2020
• To protect ALPR data to the appropriate standard, Fresno,
Los Angeles, Marin, and Sacramento should do the following:
‑ By August 2020, identify the types of data in their ALPR
systems and, as they review or draft their ALPR policies,
ensure that they clarify the types of information their officers
may upload into their ALPR systems, such as, but not limited
to, information obtained through CLETS.
‑ By August 2020, perform an assessment of their ALPR
systems’ data security features, and make adjustments to their
system configurations where necessary to comply with CJIS
policy best practices based on that assessment.
• To ensure that the agreements with their cloud vendor offers
the strongest possible data protections, by August 2020, Fresno,
Marin, and Sacramento should enter into new contracts with
Vigilant that contain the contract provisions recommended in
CJIS policy.
• To ensure that ALPR images are being shared appropriately, the
specific agencies noted should do the following:
‑ By April 2020, Fresno, Marin, and Sacramento should
review the entities with which they currently share images,
determine the appropriateness of this sharing, and take all
necessary steps to suspend those sharing relationships deemed
inappropriate or unnecessary.
‑ As Los Angeles develops its ALPR policy, it should be certain
to list the entities with which it will share ALPR images and
the process for handling image‑sharing requests.
‑ By August 2020, Marin and Sacramento should each develop
a process for handling ALPR image‑sharing requests that
includes maintaining records separate from the Vigilant
system of when and with whom they share images. The
process should verify a requesting agency’s law enforcement
purpose for obtaining the images and consider the requesting
agency’s need for the images. The process should be
documented in the agency’s ALPR policy and/or procedures.
‑ By August 2020, Fresno should revise its written procedures
for ALPR image‑sharing, as necessary, to ensure that it follows
those procedures.
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• To minimize the privacy risk of retaining ALPR images for long
periods of time, Fresno, Los Angeles, Marin, and Sacramento
should do the following:
‑ By August 2020, review the age of the ALPR images their
personnel are searching for and ensure that their retention
periods for ALPR images are based on department needs.
Each agency should reflect in its ALPR policy the updated
retention period and state in its policy that it will reevaluate its
retention period at least every two years.
‑ Include in their ALPR policies a retention period for data
or lists, such as hot lists, used to link persons of interest
with license plate images, and create necessary processes to
ensure that those data unrelated to ongoing investigations are
periodically removed from their ALPR systems.
• To ensure that ALPR system access is limited to agency staff who
have a need and a right to use ALPR data, Fresno, Los Angeles,
Marin, and Sacramento should do the following:
‑ By April 2020, review all user accounts and deactivate
accounts for separated employees, inactive users, and others
as necessary.
‑ Ensure that their ALPR policies specify the staff classifications,
ranks, or other designations that may hold ALPR system user
accounts and that accounts are granted based on need to
know and right to know.
‑ By August 2020, develop and implement procedures for
granting and managing user accounts that include, but are
not limited to, requiring that supervisors must approve
accounts for users, providing training to users before
granting accounts, suspending users after defined periods of
inactivity, and requiring regular refresher training for active
users and training for users before reactivating previously
inactive accounts. Each agency should also ensure that it has
procedures in place to deactivate an account immediately for
an account holder who separates from the agency or who no
longer needs a user account.
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February 2020
• To enable auditing of user access and user queries of ALPR
images, Fresno, Los Angeles, Marin, and Sacramento should do
the following:
‑ By April 2020, assess the information their ALPR systems
capture when users access them to ensure that the
systems’ logs are complete and accurate and that they form a
reasonable basis for conducting necessary, periodic audits.
‑ Ensure that their ALPR policies make clear how frequently
they will audit their ALPR systems, who will perform those
audits, who will review and approve the audit results, and how
long they will retain the audit documents. Each agency should
have in place by February 2021 an audit plan that describes its
audit methodology, including, but not limited to, risk areas
that will be audited, sampling, documentation, and resolution
of findings.
‑ By June 2021, implement their audit plans and complete their
first audits.
We conducted this performance audit under the authority vested in the California State Auditor
by Government Code 8543 et seq. and in accordance with generally accepted government auditing
standards. Those standards require that we plan and perform the audit to obtain sufficient,
appropriate evidence to provide a reasonable basis for our findings and conclusions based on our
audit objectives. We believe that the evidence obtained provides a reasonable basis for our findings
and conclusions based on our audit objectives.
Respectfully submitted,
ELAINE M. HOWLE, CPA
California State Auditor
February 13, 2020
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Appendix A
Summary of ALPR Survey Responses
The Audit Committee requested that we determine
Agencies That Did Not Respond to Our Survey
ALPR use among law enforcement agencies
statewide. Specifically, the Audit Committee asked • Anderson Police Department
us to determine whether agencies use ALPR
• Barstow Police Department
information, what vendors they use, and whether
law enforcement agencies have policies and • Del Norte County Sheriff’s Office
procedures to govern their use and sharing of ALPR • Lakeport Police Department
information. We surveyed 391 county sheriffs and
• Lodi Police Department
municipal police departments statewide. We relied
upon information from the California State Sheriffs’ • Mendocino County Sheriff’s Office
Association, the California Police Chiefs
• Mount Shasta Police Department
Association, and the FBI to obtain assurance that
• Oceanside Police Department
our list of statewide local law enforcement was
reasonably comprehensive. • San Francisco Sheriff’s Department
• Siskiyou County Sheriff’s Department
We received 381 responses (97 percent) to the
391 surveys we sent. Ten agencies we surveyed Source: Analysis of survey responses.
did not respond. The text box lists those agencies.
A breakdown of the law enforcement agencies’
responses to our statewide survey can be found
at http://auditor.ca.gov/reports/2019‑118/supplemental.html.
The discussion here summarizes the survey results.
Summary of Results From Agencies That Reported Using ALPR Systems
In responding to our survey, law enforcement agencies indicated
whether they use ALPR systems and, if so, what vendors’ systems
they use to collect and access ALPR information. Of the agencies
that responded, 60 percent, or 230 agencies, reported that they
currently operate or access information from ALPR systems.
Of those agencies, 96 percent said they have an ALPR usage and
privacy policy. Vigilant is the most common vendor for the agencies
that reported using ALPR systems. Figure A.1 summarizes which
vendors the 230 law enforcement agencies reported that they use.
Finally, 9 percent, or 36 of the agencies we surveyed, stated that
they are implementing or planning to implement ALPR systems.
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Figure A.1
Vigilant Is the ALPR Vendor the Majority of Law Enforcement Agencies Use
50 | OTHER*
ALPR
161 | VIGILANT VENDORS† 50 | NEOLOGY or PIPS
Source: Analysis of survey responses.
* The Other category includes vendors such as Genetec, ELSAG, and All Traffic Solutions.
† The total number of ALPR vendors used is greater than the 230 agencies that said they use
ALPR systems because some agencies use more than one vendor.
Law enforcement agencies that reported using ALPR systems
also answered questions related to their retention and sharing of
ALPR information. We asked how long the agencies retain ALPR
information not related to ongoing investigations or litigation. As
Figure A.2 shows, the retention periods varied, but the majority
of law enforcement agencies reported retention periods between
six months and two years. Additionally, we asked agencies that
operate ALPR systems if they share or sell the information
they collect with other law enforcement or public agencies.
Seventy‑three percent, or 168 agencies that use ALPR systems,
reported that they share ALPR images with other law enforcement
agencies; only three of those agencies also reported that they
share ALPR images with other public agencies that are not law
enforcement. None of the agencies we surveyed reported selling
images to other law enforcement or public agencies.
California State Auditor Report 2019-118 47
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Figure A.2
A Majority of Agencies Generally Retain ALPR Information for Between Six Months and Two Years
Length of Retention
seicnegA
fo
rebmuN
80
76
70
60
56
50
40
30
29
30
19
20 17
10
0
Less than 1+ day to 6+ months to 1+ to 2 years 2+ to 5 years More than
1 day 6 months 1 year 5 years
Source: Analysis of survey responses.
Note: Three responding agencies that use ALPR systems did not indicate a retention period for their information: Bakersfield Police Department,
Fountain Valley Police Department, and Pasadena Police Department.
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Appendix B
Scope and Methodology
The Audit Committee directed the California State Auditor to
conduct an audit of the extent to which local law enforcement
agencies are complying with existing law regarding the use of
ALPR systems. The analysis the Audit Committee approved
contained five objectives. We list the objectives and the methods
we used to address them in Table B.
Table B
Audit Objectives and the Methods Used to Address Them
AUDIT OBJECTIVE METHOD
1 Review and evaluate the laws, rules, and Reviewed relevant state laws, regulations, and other background materials applicable to the
regulations significant to the audit objectives. use and operation of ALPR systems by local law enforcement.
2 To the extent possible, determine the following • Surveyed 391 county sheriff and municipal police departments statewide.
for law enforcement agencies statewide:
• Obtained and verified a list of statewide local law enforcement agencies, using
a. Whether they use ALPR information and, information from the California State Sheriffs’ Association, the California Police Chiefs
if so, what vendors they use to access Association, and the FBI.
this information.
• Questioned agencies regarding their use of ALPR systems, including whether they use
b. Whether they have policies and procedures
or are planning to use an ALPR system; if they share or sell the ALPR information; if
in place governing the use and sharing of
their ALPR storage is CJIS‑compliant; which system they use to store, share, or access
ALPR information.
ALPR information; if they have a usage and privacy policy and post the policy on their
website; how long they retain ALPR information; how many department personnel
have access to the ALPR data; and how many total personnel their department has.
Full questions and a breakdown of the responses are on our website at
http://auditor.ca.gov/reports/2019‑118/surveys.html.
• Created an interactive graphic to display responses by county, assembly district, and
senate district at http://auditor.ca.gov/reports/2019‑118/supplemental.html.
• The survey responses were self‑reported, and we did not verify their accuracy.
continued on next page . . .
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AUDIT OBJECTIVE METHOD
3 Examine the use of ALPRs by the Sacramento
County Sheriff’s Office and Department of
Human Assistance, the Los Angeles Police
Department, the Fresno Police Department,
and the Marin County Sheriff’s Office by
performing the following:
a. Determine whether they have policies and • Interviewed the agencies’ ALPR administrators.
procedures in place regarding ALPR systems
• Obtained and reviewed ALPR policies and procedures and determined whether each
and whether those policies contain the
agency met state law requirements in this area.
elements state law requires.
b. Determine whether they have followed • Interviewed the agencies’ public information officers.
state law regarding all required public
• Obtained evidence of public notifications and public hearings and determined whether
notifications related to ALPR systems and
each agency met state requirements in this area.
information, including required public
hearings.
c. Determine whether they maintain records of • Interviewed the agencies’ ALPR administrators.
access to ALPR information from both within
• Reviewed access records from the agencies’ ALPR systems.
and outside the agency that includes all
required documentation and whether they • Determined whether the agencies conducted any audits or monitoring by interviewing
have ensured that ALPR information has only ALPR administrators, staff of internal audit divisions, and executive staff of any oversight
been used for authorized purposes. entities. We also reviewed relevant policies and procedures.
• Reviewed the agencies’ internal affairs files for any cases involving ALPR misuse.
• Reviewed Justice’s and the FBI’s audits of the agencies’ IT security and the safeguards
those audits identified.
d. Determine whether they have sold, shared, • Interviewed the agencies’ ALPR administrators.
or transferred ALPR information only to
• Reviewed reports and records about data sharing from the agencies’ ALPR systems.
other public agencies, except as otherwise
permitted by law, and whether they have • Reviewed existing memorandums of agreement and understanding for data sharing.
properly documented these activities.
• Interviewed executive staff at Vigilant regarding ALPR system functionality and their
procedures for verifying the law enforcement purpose of client agencies.
e. Determine the nature of any contracts • Interviewed Justice staff responsible for protecting criminal justice information.
with third‑party vendors related to
• Evaluated the agencies’ contracts with third‑party vendors and determined whether the
ALPR information.
contracts contained adequate protections for information in the agencies’ ALPR systems.
4 Evaluate whether current state law governing • Interviewed agencies’ investigators and ALPR program administrators.
ALPR programs can be enhanced to further
• Reviewed the information in the agencies’ ALPR systems and identified the necessary
protect the privacy and civil liberties of
protections for that information.
California residents.
• Obtained the agencies’ justifications for their ALPR data retention periods.
• Analyzed six months of the agencies’ ALPR search records— between late January and
September 2019, depending on when we visited the agencies—to determine how often
the agencies’ personnel searched for older data in their ALPR systems.
• Reviewed other states’ ALPR data retention laws based on a report from the National
Conference of State Legislatures and identified best practices for data retention.
• Analyzed laws pertaining to privacy, personal information, and criminal justice
information and determined whether changes to current ALPR law would further
protect the privacy and civil liberties of California residents.
5 Review and assess any other issues that are Reviewed informational material produced by law enforcement agencies, nonprofit
significant to the audit. organizations, and other entities to identify concerns surrounding privacy and
ALPR systems.
Source: Analysis of state law, policies, information, and documentation identified in the table column titled Method.
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Assessment of Data Reliability
The U.S. Government Accountability Office, whose standards
we are statutorily obligated to follow, requires us to assess
the sufficiency and appropriateness of computer‑processed
information that we use to support our findings, conclusions, and
recommendations. In performing this audit, we relied on electronic
data files we obtained from Fresno, Los Angeles, Marin, and
Sacramento. These files included reports from the agencies’ ALPR
systems. Because the agencies relied on remote third‑party systems
to produce the reports, our analysis of these reports was limited to
verifying that we had received the information we requested.
We did so by reviewing source materials such as user manuals,
interviewing vendor staff, and confirming with the agency staff that
the number of records in the files we received were correct. We also
used electronic lists from the California Police Chiefs Association
and the California State Sheriffs’ Association to compile a list
of statewide police and sheriff departments for our survey. We
verified the nature of the data with the associations’ staffs, and we
also verified record counts by comparing the provided lists with
FBI crime‑reporting data. We found the data to be sufficiently
reliable for our purposes.
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*
1
2
* California State Auditor’s comments appear on page 61.
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Comments
CALIFORNIA STATE AUDITOR’S COMMENTS ON THE
RESPONSE FROM THE LOS ANGELES POLICE DEPARTMENT
To provide clarity and perspective, we are commenting on
the response to our audit report from the Los Angeles Police
Department. The numbers below correspond with the numbers
we have placed in the margin of its response.
Los Angeles is the only one of four agencies we audited that did 1
not have the ALPR policy state law requires. As we describe on
page 15, state law requires law enforcement agencies to have written
usage and privacy policies and for the policies to include various
elements. As we describe on page 17, the program administrator for
Los Angeles initially believed that the agency’s many IT policies
cover the ALPR program, but we identified deficiencies in the
policies he shared with us. When we brought those deficiencies
to the administrator’s attention, he acknowledged the need for
Los Angeles to have an ALPR policy.
We stand by our conclusion that Los Angeles does not follow best 2
practices for granting users ALPR system access. As we describe
on page 33, of the four agencies we reviewed Los Angeles was
the most lax in its approach to authorizing user accounts. The
protocol its IT division follows is to include its ALPR software
on each computer it assigns to staff, regardless of their position.
Thus, staff who do not perform functions related to the ALPR
system and possibly have not had training, nevertheless have access
to the system. Moreover, on page 34 we state that the detective
who conducts ALPR training confirmed that Los Angeles has not
required training before users can access the ALPR system.
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*
1
2
2
* California State Auditor’s comments begin on page 67.
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4
5
5
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6
6
7
8
9
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Comments
CALIFORNIA STATE AUDITOR’S COMMENTS ON THE
RESPONSE FROM THE MARIN COUNTY SHERIFF’S OFFICE
To provide clarity and perspective, we are commenting on the
response to our audit report from the Marin County Sheriff’s Office.
The numbers below correspond with the numbers we have placed in
the margin of its response.
Marin’s response correctly notes that our review of its internal affairs 1
investigations records did not identify evidence of abuse or misuse
of ALPR data. However, as we state on page 37, we do not consider
this absence as proof that no instances of ALPR misuse occurred.
There is the possibility that misuse occurred and went unnoticed and
unreported, particularly since Marin does not conduct audits of its
ALPR system.
During our exit conference, we specifically informed Marin that 2
we would send it only those portions of the draft report that were
relevant to it. The text that we redacted pertains to the other entities
that were part of the audit and that we are required by law to keep
confidential. Further, during its review of the draft report, Marin did
not communicate with us to seek clarification regarding the report
content we provided, despite our providing multiple opportunities
for it to do so.
Marin is incorrect in stating that we contend that the license plate 3
images Marin collects qualify as personal information. On page 11, we
note that a law enforcement agency can enter additional information,
such as personal information, into its ALPR system. However, we do
not assert that the ALPR image alone contains personal information.
Marin has mischaracterized our finding. In its response, Marin states 4
that we based our conclusion on a free‑text box wherein a user could
enter an individual’s name and attach it to a license plate image.
However, as we describe on pages 18 and 19, we based our conclusion
on information that users enter into open text fields as part of license
plate searches, specifically the fields for case numbers and purpose
for the searches. On page 37, we note that Marin requires users to
enter both case numbers and reasons for the search before allowing
such searches. Although we did not find evidence users had entered
personal information in combination with other sensitive information
in the six months of search records we studied, the fact that these
text fields exist means that users could enter such information
during ALPR searches, as we point out on pages 18 and 19. Moreover,
Marin’s ALPR policy does not prohibit users from entering personal
information in combination with other sensitive information in its
ALPR system.
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5 We disagree with the focus of Marin’s response, which implies
that the vendor’s security controls are a suitable substitute for
specific contract safeguards. As we show in Figure 3 on page 22,
Marin’s contract does not contain any of the safeguards CJIS policy
recommends for contracts with cloud vendors. We note on page 21
that CJIS policy states that ambiguous contract terms can lead to
controversy over data privacy and ownership rights, whereas a
contract that clearly establishes data ownership acts as a foundation
for trust that the cloud vendor will protect the privacy of the
agency’s data.
6
We disagree with Marin’s belief that it has managed its image
sharing appropriately. Although Marin described in its response
the type of information that it could maintain to document
its image‑sharing decisions, it did not provide such evidence
documenting why it made past sharing decisions, and its ALPR
policy does not include a process for approving image‑sharing
requests, as we state on page 26. Moreover, Marin acknowledged in
its response the issue we describe on page 26 regarding ICE and the
fact that the status of Marin’s sharing relationship with ICE was not
always visible to Marin. This issue underscores the need for Marin
to maintain records regarding sharing decisions.
7
Marin appears to miss the point of our recommendation. As
we state on page 29, we concluded that Marin did not establish
its retention period based on when it uses the ALPR images it
captures. On page 31, we mention minor and complex crimes
as examples of ALPR data being used narrowly, such as for the
single purpose of locating stolen vehicles, or broadly, such as
for investigation of crimes in addition to stolen vehicles. Our
recommendation—based on our analysis of Marin’s search activity
as referenced on page 30—provides a method for Marin to better
align how long it retains ALPR data with whether it actually uses
the data as they age.
8
The reasons Marin cites in its response for not adopting our
recommendation are not valid. Requiring a supervisor to approve
a user for an ALPR account is a meaningful step in establishing
that user’s need to access ALPR data and right to know what the
data portray in an effort to avoid the ALPR data being misused. In
point 4 above, we describe that the existence of text fields in the
ALPR system allows for personal information to be linked to license
plate images. Further, we note that Marin has no policy prohibiting
its users from entering personal information in its ALPR system.
In addition, despite Marin’s claim of training all users, we state on
page 34 that Marin does not require staff to renew their training
when reactivating their user accounts following long periods of not
using the ALPR system. Finally, we found that contrary to Marin’s
assertion, it had not regularly audited its system. As we discuss
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on page 37, Marin’s ALPR administrator was unaware of the
state law requiring audits of ALPR systems, so he had not been
conducting them. Despite recent efforts to institute some form
of monitoring, as we describe on page 38, the limitations in its
approach led us to conclude that Marin does not have sufficient
protocols in place to detect the misuse of user accounts.
Marin’s assertion is incorrect. As we describe on page 35, we 9
reviewed Marin’s processes for disabling the accounts of separated
employees. Although Marin’s ALPR administrator informed us
of his approach for deactivating an account when he receives an
all‑staff email that an employee is separating from the department,
we found such an email dated August 6, 2019, after which
one separated employee continued to hold an active account as
of October 22, 2019. After we informed the administrator of this
employee’s continued access, the administrator acknowledged
that the account was still active, and we directly observed him
deactivating the account.
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*
1
1
* California State Auditor’s comments begin on page 77.
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Comments
CALIFORNIA STATE AUDITOR’S COMMENTS ON
THE RESPONSE FROM THE SACRAMENTO COUNTY
SHERIFF’S OFFICE
To provide clarity and perspective, we are commenting on the
response to our audit report from the Sacramento County Sheriff’s
Office. The numbers below correspond with the numbers we have
placed in the margin of its response.
We stand by the language we use to describe Sacramento’s ALPR 1
program. Our report provides appropriate context and sufficient
evidence to support our findings. Further, the Results in Brief
section of the report serves as a summary of the report as a whole
and as such it represents the overall conclusions for this report. The
details of our findings and conclusions are included in the Audit
Results section of the report.
We disagree with Sacramento’s contention that the department’s 2
current contract is thorough. On pages 22 and 23, we acknowledge
that Sacramento updated its contract with Vigilant in
September 2019. In reviewing that latest version, we determined
that it is missing some of the best practices outlined in CJIS policy,
as we show in Figure 3 on page 22. On page 21, we note that CJIS
policy states that a contract that clearly establishes data ownership
acts as a foundation for trust that the cloud vendor will protect the
privacy of the agency’s data.
Sacramento’s response implies that a process for approving 3
image‑sharing requests and maintaining records outside of
the Vigilant system was already in place. However, although
Sacramento states that it began developing a ticketing system for
handling technology requests more than four years ago, as we
discuss on page 26, Sacramento could not provide any evidence of
records outside of the Vigilant user interface demonstrating when
or why it agreed to share with particular entities. As we further
point out on page 26, Sacramento’s ALPR policy currently does not
include a process for approving sharing requests.
Sacramento’s proposed study of ALPR images may benefit its 4
ALPR program. Our analysis of the search records from the
agencies we reviewed—summarized on page 30 and in Table 2—
presents one method of identifying the age of the data personnel
are using. We point out on page 31 that the agencies’ existing
ALPR systems provide the ability to conduct such an analysis.
Nevertheless, our recommendation does not preclude the type of
analysis Sacramento describes in its response.
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5
We stand by our recommendation that Sacramento should have
a policy that clearly states the staff classifications, ranks, or other
designations that may hold ALPR system user accounts and that
accounts are granted based on a need to know and a right to know.
As we state on page 32, each ALPR administrator, including
Sacramento’s, stressed the concept of “need to know, right to know.”
Assigning an individual an ALPR account based strictly on his or
her classification or role—the practice Sacramento follows—does
not ensure that an individual has a need to know because of their
specific assigned work.
6
Sacramento’s concern about bias is unfounded. To meet generally
accepted government auditing standards, which my office
is obligated to comply with, we have and follow policies and
procedures for all audits to ensure that we identify and rectify any
threats to our independence, including bias. Moreover, we follow
quality control procedures on every audit that ensure that we
have sufficient and appropriate evidence to support our findings
and conclusions.
7
Sacramento received draft text that was relevant to our findings
about it. State law requires us to keep confidential information
about an unpublished audit. Consequently, we cannot share with
one agency information about another. Sacramento received a draft
audit report with redacted information regarding other agencies as
necessary to maintain confidentiality. During our exit conference,
we stressed that staff should contact us with questions they might
have about the draft report during the formal review period;
Sacramento did not contact us. We also contacted Sacramento’s
ALPR administrator during the formal review period to inquire
about questions staff may have, and he did not return our call.