Mill Valley subcommittee trims Flock camera data retention to 72 hours, cites safeguards

An unidentified member of Mill Valley’s Police Governance Subcommittee told attendees the city is reducing how long it keeps license-plate reader data collected by Flock cameras from seven days to 72 hours and reaffirmed safeguards intended to limit data sharing and misuse.

The speaker, identified in the transcript only as a Police Governance Subcommittee member, said Mill Valley adopted Flock cameras in February 2025 to address public-safety concerns such as stolen vehicles, suspect vehicles and missing persons and that the city intentionally deployed a limited number of devices at three primary ingress and egress points rather than building a citywide grid. “We monitor 3 primary ingress egress points rather than building a citywide grid,” the member said.

The announcement follows public concern in other jurisdictions about widespread sharing of automatic license-plate reader (ALPR) data. The member said Mill Valley has “opted out of both nationwide and statewide lookup tools” and conducts ongoing internal audits to confirm there has been no unintended or improper access to ALPR data. The member also stated, “Mill Valley Police Department does not use facial recognition technology or AI software with its 2 PTZ” cameras.

Citing a decision already made by the subcommittee, the speaker said, “We have made the decision to adjust our data retention policy from 7 days. We're going to cut it in half to 72 hours.” The member framed that change as an additional safeguard to limit the amount of stored information at any given time.

The member acknowledged the trade-offs between risk and public benefit but described operational successes tied to the system, saying department use of plate-reader leads helped officers locate “at least 2 recent instances” in which a cache of weapons was found. The remarks were presented as examples of how the technology has produced investigative leads in Mill Valley.

The speaker also thanked community members for raising concerns during public comment and said those remarks motivated the subcommittee to revisit policies. The subcommittee asked detailed questions of Chief Navarro, who was present, and the member said Chief Navarro will prepare a written report with frequently asked questions to be posted on the city website.

No vote or formal ordinance was recorded in the transcript for this meeting; the retention change was described as a subcommittee decision and a policy adjustment rather than an enacted ordinance. The city’s next procedural step, according to the transcript, is publication of the chief’s written report and continued review of camera configuration, oversight and related policy.