A. AUTOMATED LICENSE PLATE READER (ALPR) CAMERAS DATA RETENTION
AND SHARING
It is recommended that the City Council receive and discuss the utilization of Automated License Plate Reader (ALPR) cameras and adopt a motion approving staff recommendations on data retention and sharing.
Cotati City Council
Agenda Staff Report
Item type: REGULAR AGENDA (ACTION)
To: Cotati City Council
Subject: AUTOMATED LICENSE PLATE READER (ALPR) CAMERAS
DATA RETENTION AND SHARING
Date: May 27, 2025
Written by: Chris Simmons, Chief of Police
Recommendation
It is recommended that the City Council receive and discuss the utilization of Automated License Plate Reader (ALPR) cameras and adopt a motion approving staff recommendations on data retention and sharing.
Background
On March 25, 2025, the Police Chief presented the annual Police Chief’s report summarizing public safety activities in 2024. At that meeting, the City Council discussed the Police Department’s use of Automated License Plate Readers (ALPRs), specifically the retention period of license plate images/locations. At the end of the conversation, the City Council requested that staff return with an agendized item to discuss the topic in more detail.
In prior City Council discussions around the use of ALPRs, the City Council raised concerns about holding license plate images and locations and balancing the potential data privacy concerns with public safety utility of ALPR systems. As a result of those discussions, the City Council directed that the data retention period be lowered from 1 year to 6 months and requested a report back in the next annual report discussing the observed benefits of the system during that time period. The intent, as understood by staff, was to determine if 6 months was in fact the optimal retention period or if a shorter period would still effectively accomplish the public safety purpose.
The City currently has four patrol vehicles upfitted with Axon dash-cameras that have ALPR capabilities. Currently, there are no fixed ALPR cameras and data sharing with neighboring law
FOR REFERENCE ONLY
enforcement agencies is not enabled.
Analysis/Discussion
Based on experience, ALPR cameras are often a key tool in providing real-time crime (inprogress) alerts and aiding police investigations, providing law enforcement with crucial evidence to identify suspects, witnesses, and the sequence of events surrounding a crime. ALPR cameras, whether installed at fixed locations or placed in a vehicle, record vehicle description data, location, and date/time. This technology is objective and unbiased, only recording otherwise public information and nothing about the personal characteristics or identifying information of drivers or passengers within camera view.
Once information is collected, the automated system checks the license plate data against the same state databases that police officers use to check vehicle license plates. This includes stolen vehicles and other crime-related vehicles listed in the database connected to crimes, missing persons related vehicles, and other authorized alerts that law enforcement agencies have placed in the system. Any license plates matching law enforcement identified vehicles that are within the authorized fields are relayed to officers and dispatchers monitoring the system as an alert.
Officers can then attempt to locate vehicles related to alerts. Every alert ultimately must be confirmed with the originating agency and the officer receiving the alert must confirm the information through CLETS before taking any enforcement action. ALPR data is also prohibited for immigration purposes. California law also prohibits law enforcement agencies from sharing data with agencies outside the State of California.
Recommendation
Data Retention
Based on local experience and experience from other agencies, staff believe that further reducing the retention period from 6 months to 1 month will still provide sufficient information to assist in solving the vast majority of crimes, while balancing the data privacy concerns as well as the costs to the City for retaining this data for longer periods of time.
Data Sharing
Another recommended change to the current procedure is to open up 1 to 1 data sharing with other California law enforcement agencies and be able to receive data from public ALPRs. In particular, police staff have found that access to neighboring ALPRs will provide a significant public safety benefit, including the ALPR cameras at Lowe’s Home Improvement, the 101 freeway, 116 highway/Stony Point, Rohnert Park, Petaluma, Santa Rosa, and other cameras in Sonoma County jurisdictions. Additionally, Sonoma State University (SSU) is in the process of installing ALPR cameras, and given our close coordination and dispatching of SSU, real-time access to vehicle flags will be critical. Without access, which is established with data sharing, the police have to rely on other agencies proactively contacting Cotati to inform us of vehicle flags in or around Cotati.
Financial Considerations
To enable data sharing with other local law enforcement agencies and receive data from public ALPRs, it would require enabling a subscription service. This service, with a 1-month data retention, would require a two year service contract at $6,000 per year that also includes 2 fixed ALPRs. Longer data retention significantly increases the annual costs and is not recommended.
Environmental Issues
This action is exempt from the California Environmental Quality Act (CEQA) because it is not a project which has a potential for resulting in either a direct physical change in the environment, or a reasonably foreseeable indirect physical change in the environment, pursuant to CEQA Guideline section 15378.