ALPR Audit Logs and Search Records

What a search log records

A plate read is created when a camera sees a car. A search record is created when a person queries the stored reads. These are separate records. Flock’s License Plate Reader Policy says “all queries of the LPR system are stored for auditing purposes,” including:

• username
• date and time
• purpose of the query
• the license plate and any other elements used to search, such as vehicle characteristics

Flock says each search is tied to a specific user and that a public-safety reason is recorded with it. In August 2026, Flock announced that by the end of the year officers will have to enter a case code for every search. Emergency searches that bypass the code will be flagged for review. Its Audit Assistance tool, which flags unusual searches for an administrator, will also become mandatory for law enforcement customers. These are vendor statements about Flock’s system. Other ALPR vendors log differently.

Agency rules: reasons, approvals and audits

Flock says it “encourages customers to adopt a use policy and implement a regular auditing schedule.” The actual rules come from each agency. The Knoxville Police Department’s policy is one example:

• Every inquiry must have “an associated report number documented and a specific reason for the request” (¶ 15).
• Searches run for another agency need approval from a lieutenant or above, documented with the approving supervisor, the requesting agency and officer, and the reason (¶ 15a).
• “All queries in the ALPR system will be logged and available for auditing and review,” with audits conducted monthly (¶ 27).

Other agencies’ rules can be stricter, looser, or missing. The policy in force at the time of the search is what matters.

How auditing has worked in practice

Rules on paper haven’t always been followed. In its 2020 review of four California agencies, the California State Auditor found that the agencies had “few safeguards for creating ALPR user accounts and have not audited the use of their systems.” None had a usage and privacy policy implementing every requirement state law had imposed since 2016. Flock’s 2026 announcement tied its mandatory audit tools to reviews that it said were associated with arrests of officers accused of misusing the system.

Why search records matter in a case

When stored ALPR data plays a role in a case, the search records can answer questions the plate read can’t:

• Timing. When was the vehicle first searched for, and did that come before or after other investigative steps or a warrant?
• Scope. Was the query for one plate on one day, or a partial plate or vehicle description across many cameras and weeks? Scope can bear on whether a search was a Fourth Amendment search. See is ALPR a search?
• Stated reason. Does the recorded purpose or case code match the investigation, and did it comply with policy?
• Who searched. Was it the investigating agency, or another agency through a sharing arrangement? See data retention and sharing.
• Completeness. Did the search return other vehicles or reads that the case file doesn’t mention?

These questions may support a motion to suppress, a challenge to a warrant affidavit, or cross-examination at trial.

Limits of the logs

• A log shows that a search happened and what was entered. It doesn’t prove the stated reason was true.
• What gets logged depends on the vendor and how the agency configured the system.
• A policy violation isn’t automatically a constitutional violation, and it doesn’t automatically lead to suppression.

How to ask for these records is covered in requesting ALPR records in discovery.