ALPR Policy

San Marino Police Department

Policy 461 - Automated License Plate Readers (ALPRs)



The purpose of this policy is to provide guidance for the capture, storage and use of digital data obtained through the use of Automated License Plate Reader (ALPR) technology.


The ALPR technology, also known as License Plate Recognition (LPR), allows for the automated detection of license plates. It is used by the San Marino Police Department to convert data associated with vehicle license plates for official law enforcement purposes, including identifying stolen or wanted vehicles, stolen license plates and missing persons. It may also be used to gather information related to active warrants, homeland security, electronic surveillance, suspect interdiction and stolen property recovery. All installation and maintenance of ALPR equipment, as well as ALPR data retention and access, shall be managed by the Support Services Commander. The Support Services Commander will assign members under his/her command to administer the day-to-day operation of the ALPR equipment and data.


 The Support Services Commander shall be responsible for developing guidelines and procedures to comply with the requirements of Civil Code § 1798.90.5 et seq. This includes, but is not limited to (Civil Code § 1798.90.51; Civil Code § 1798.90.53): 

(a) A description of the job title or other designation of the members and independent contractors who are authorized to use or access the ALPR system or to collect ALPR information.

(b) Training requirements for authorized users.

(c) A description of how the ALPR system will be monitored to ensure the security of the information and compliance with applicable privacy laws.

(d) Procedures for system operators to maintain records of access in compliance with Civil Code § 1798.90.52.

(e) The title and name of the current designee in overseeing the ALPR operation.

(f) Working with the Custodian of Records on the retention and destruction of ALPR data.

(g) Ensuring this policy and related procedures are conspicuously posted on the department’s website.



Use of an ALPR is restricted to the purposes outlined below. Department members shall not use, or allow others to use the equipment or database records for any unauthorized purpose (Civil Code § 1798.90.51; Civil Code § 1798.90.53).

(a) An ALPR shall only be used for official law enforcement business.

(b) An ALPR may be used in conjunction with any routine patrol operation or criminal investigation. Reasonable suspicion or probable cause is not required before using an ALPR.

(c) While an ALPR may be used to canvass license plates around any crime scene, particular consideration should be given to using ALPR-equipped cars to canvass areas around homicides, shootings and other major incidents. Partial license plates reported during major crimes should be entered into the ALPR system in an attempt to identify suspect vehicles.

(d) No member of this department shall operate ALPR equipment or access ALPR data without first completing department-approved training.

(e) No ALPR operator may access department, state or federal data unless otherwise authorized to do so.

(f) If practicable, the officer should verify an ALPR response through the California Law Enforcement Telecommunications System (CLETS) before taking enforcement action that is based solely on an ALPR alert.



The Support Services Commander is responsible for ensuring systems and processes are in place for the proper collection and retention of ALPR data. Data will be transferred from vehicles to the designated storage in accordance with department procedures. All ALPR data downloaded to the server should be stored for a minimum of one year (Government Code § 34090.6) and in accordance with the established records retention schedule. Thereafter, ALPR data should be purged unless it has become, or it is reasonable to believe it will become, evidence in a criminal or civil action or is subject to a discovery request or other lawful action to produce records. In those circumstances the applicable data should be downloaded from the server onto portable media and booked into evidence.



All data will be closely safeguarded and protected by both procedural and technological means. The San Marino Police Department will observe the following safeguards regarding access to and use of stored data (Civil Code § 1798.90.51; Civil Code § 1798.90.53): 

(a) All ALPR data downloaded to the mobile workstation and in storage shall be accessible only through a login/password-protected system capable of documenting all access of information by name, date and time (Civil Code § 1798.90.52).

(b) Members approved to access ALPR data under these guidelines are permitted to access the data for legitimate law enforcement purposes only, such as when the data relate to a specific criminal investigation or department-related civil or administrative action.

(c) ALPR system audits should be conducted on a regular basis. For security or data breaches, see the Records Release and Maintenance Policy.

461.6 POLICY

The policy of the San Marino Police Department is to utilize ALPR technology to capture and store digital license plate data and images while recognizing the established privacy rights of the public. All data and images gathered by the ALPR are for the official use of this department. Because such data may contain confidential information, it is not open to public review.


The ALPR data may be shared only with other law enforcement or prosecutorial agencies for official law enforcement purposes or as otherwise permitted by law, using the following procedures:

(a) The agency makes a written request for the ALPR data that includes:

1. The name of the agency.

2. The name of the person requesting.

3. The intended purpose of obtaining the information.

(b) The request is reviewed by the Support Services Commander or the authorized designee and approved before the request is fulfilled.

(c) The approved request is retained on file.

Requests for ALPR data by non-law enforcement or non-prosecutorial agencies will be processed as provided in the Records Maintenance and Release Policy (Civil Code § 1798.90.55).



The Support Services Division Commander should ensure that members receive department approved training for those authorized to use or access the ALPR system (Civil Code § 1798.90.51; Civil Code § 1798.90.53).