Surveillance Technology Impact Report
Automated License Plate Recognition
October 17, 2023
315 Fourth Avenue, MS P-200, Chula Vista, CA
91910 www.chulavistapd.org (619) 691-5150 fax (619) 585-5610
SUMMARY
Automated License Plate Recognition (ALPR) systems involve the use of digital camera systems paired with software to identify license plate numbers. ALPR systems function by automatically taking a photographic image of a vehicle’s license plate and transforming that image into alphanumeric characters using optical character recognition or similar software.
The images often include the license plate as well as enough of the car to allow for identification of the make and model.
The images and data about the license plate number and geolocation of the image are stored in the ALPR system for a pre-determined period, after which the images and data are automatically purged from the system. No personal identifying information is generated or stored in the ALPR system.
ALPR technology originated in the United Kingdom in the mid-1970s and has been widely used by law enforcement worldwide since 2001. A January 2012 Police Executive Research Forum (PERF) Technology Summit in Washington D.C. showed 71% of surveyed police departments in the United States employed ALPR systems to some extent and 85% planned to acquire or expand their use of ALPR systems in the next five years.
Today, most law enforcement agencies in San Diego County also use ALPR systems in some facet. In recent years, many municipalities in San Diego County have expanded their ALPR programs to include fixed ALPR systems and have publicized numerous success stories attributed to the use of ALPR technology.
The above table shows San Diego County Law Enforcement agencies that currently have ALPR systems and the number of fixed/mobile devices. The “ * “ shows agencies that are in the process of procuring ALPR systems.
Since it was originally authorized by the City Council in 2007, an ALPR system has been a component of the Police Department’s crime-fighting and investigative strategy and has been used to identify vehicles associated with criminal suspects, missing persons, and other vehicles related to official police investigations. ALPR improves the Department’s ability to narrow the focus of investigations managed by its limited investigative resources, deter the occurrence of crime, and enhance public safety.
Surveillance Technology Impact Report: Automated License Plate Recognition
Currently, the Police Department operates a maximum of four marked patrol cars equipped with ALPR camera systems that operate while the vehicles are in use. Patrol cars are assigned to patrol officers on an available basis and are not assigned based on geography. Due to shift overlaps, patrol cars may not be used on some shifts (i.e. a day shift officer drives one, making it unavailable for the next shift, but available for an officer on the overnight shift to drive).
ALPR systems do not collect nor store sensitive personal information.
As a result of state grant funding that includes the expansion of the Police Department’s ALPR system, and under an action item brought before the City Council on October 17, 2023, the Police Department proposes to expand the Department’s ALPR program to add 150 fixed-location ALPR cameras.
Unlike mobile ALPR cameras, fixed ALPR systems cannot be readily moved throughout the city to drive through crime scenes or areas with an increased risk of crimes such as shopping malls. (Mobile ALPR systems are sometimes operated in an area where a significant crime has occurred, and potentially help detectives to identify vehicles associated with suspects.)
Fixed ALPR cameras also have a reduced capability for immediate interdiction of crimes in-progress. While fixed ALPR cameras have the capacity of alerting personnel to a crime in-progress, the alerting process is multi-layered, is dependent on which users are logged into the system at any given time, and often goes through third-party personnel in the Police Department’s communications center. In mobile systems, an officer driving an ALPR-equipped patrol vehicle can be immediately alerted to a potential criminal offense or criminal offender, allowing the officer to take immediate action to investigate the alert and potentially stop a crime in progress, locate a missing person, or identify a wanted vehicle.
But fixed ALPR cameras can be mounted on traffic lights and poles in major thoroughfares, points of ingress or egress into or out of the city limits and positioned in areas with high traffic density. Since criminal offenders aren’t bound to stay within a particular location within the city, or even within the city limits, a fixed ALPR camera’s ability to capture images from key locations 24 hours a day provides detectives with significantly improved capability to identify and locate vehicles involved in crimes that have victimized members of our community.
POTENTIAL FOR DISPROPORTIONATE ADVERSE IMPACTS, AND MITIGATION
The Police Department is aware of concerns that ALPR data will be shared with other agencies that engage in immigration enforcement. Community members have also expressed concern that ALPR data will be used for purposes other than law enforcement, or could disproportionately affect specific communities or cultures. The Police Department is also aware of concerns that ALPR data may be used to track the movements of people around sensitive areas, such as houses of worship, health clinics and may be used to infringe upon the First Amendment rights of individuals.
The Chula Vista Police Department has had an ALPR program since 2007. At the inception of the program the department put safeguards in place to minimize or mitigate potential disproportionate impacts. Access to the ALPR system is limited only to employees with a justifiable need related to their official duties, such as sworn officers, dispatchers, and crime analysts. The department established a comprehensive use policy requiring that all users attend a minimum of 2-hours training. The department requires that only authorized users may access the system, and then only when necessary to conduct their official duties, otherwise known as a need-to-know and right-to-know basis. Authorized users can only access the system for the purposes of a police investigation, and user activity in the system is logged for auditing by supervisory or management personnel.
Surveillance Technology Impact Report: Automated License Plate Recognition
The department’s use policy also specifies which law enforcement agencies we may authorize to search Chula Visa’s ALPR data. The ability to share ALPR data with other agencies is restricted to command personnel for the department.
As a matter of practice, the department shares ALPR data with only California state law enforcement agencies. The department does not share data with federal law enforcement agencies, nor with any law enforcement agency for the purpose of immigration enforcement. The department’s use policy was recently updated based on the proposed expansion of the ALPR System, and includes a change to the department’s retention guidelines. The department proposes to reduce the retention of ALPR data from one year, to 30-days. The ALPR system will be configured to automatically purge ALPR data after the 30-day period expires.
ALPR is content-neutral; it does not identify the race of the driver or the registered owner of the vehicle. To ensure that the Police Department continues to build trust in the community and mitigates any potential disparate impacts, the Police Department will continue to adhere to its use policy of limiting access and use of the ALPR system to official investigations or community caretaking functions, and limiting access to the ALPR system to trained and authorized department personnel. Further, the Police Department will continue to audit the ALPR system on a regular basis to provide a measure of proactive accountability. In doing so, the department can mitigate the likelihood of disparate treatment of individuals based on factors not related to true police investigations and simultaneously minimize perceived oversurveillance of specific communities or demographics of our city.
The department does not collect data on the demographics about the owners or operators of vehicles. The ALPR program operates as a stand-alone system and does not capture nor store personally identification information.
The department recently decided to expand the ALPR program to add fixed camera locations throughout the city. These locations were determined based on population density, traffic patterns, ingress locations, egress locations into and out of the city and crime data, and locations were identified so as to distribute ALPR cameras in such a way to minimize the potential for disparate impacts on local communities.
POTENTIAL FOR ADVERSE IMPACTS ON THE SECURITY AND ACCESS TO SENSITIVE PERSONAL
INFORMATION, AND MITIGATION
ALPR systems do not collect nor store sensitive personal identifiable information and are stand-alone systems. The system also does not access outside or third-party databases that contain personal identification information.
Nonetheless, the Police Department tightly controls access to the ALPR system and logs user activity in the system for proactive audits. Access to the system is granted only with authorization, after training, and only through unique usernames and passwords for each authorized user. Department policies prohibit sharing usernames and passwords.
FINANCIAL IMPACTS AND FUNDING SOURCE
Approval of the Police Department’s proposal to accept $3,037,986 in grant funds from the Board of State and Community Corrections for the Organized Retail Theft Prevention Grant Program, and to therefore expand the Police Department’s ALPR system, will designate $1,372,500 of grant funds for the expanded ALPR system.
Because the grant period covers three fiscal years, subsequent budgets will include allocations for the expanded ALPR system based on costs provided by the provider. Currently, these costs are estimated at $472,500 in year one and $450,000 a year for year two and year three. This is in addition to the annual costs of the Police Department’s pre-existing ALPR system, estimated at $73,000 per year.
Surveillance Technology Impact Report: Automated License Plate Recognition
POTENTIAL TECHNOLOGY ALTERNATIVES
ALPR is a technological capability rather than a specific tool. While a variety of tools exist that can perform the functions of ALPR, the Police Department is not aware of any other technology that does what ALPRs technology can do.