Thornton police outline tightened ALPR audit rules after council questions

The Thornton Police Department on Tuesday described changes to how it audits and oversees its automatic license‑plate reader (ALPR) system, saying the goal is to increase accountability after council and public scrutiny.

Police chief Jeff said the department will make a secondary reason field mandatory and convert it from free text to a dropdown so searches more consistently include case numbers or call‑for‑service identifiers. "By making these mandatory, ... we should start seeing significantly more case numbers and call for service numbers included with the searches," he said, adding the change will make omissions stand out "like a red flag, during the audit process."

The department also plans to expand its internal audit capacity from a single administrator to a five‑person audit team, run audits weekly, and create an audit log that records audit date, time frame reviewed, findings, how concerns were resolved and who completed the audit. Chief Jeff said auditors will be able to compare officer schedules and search timing to spot anomalous use and that so far the department has "not found any evidence of misuse by department employees."

The presentation included background on the ALPR program — the department began using an LPR system in 2019 and expanded deployments and vendors in 2022 and 2024 — and a vendor comparison that found all three major products (Flock, Motorola and Axon) claim CJIS compliance and offer agency‑controlled multi‑factor authentication. Chief Jeff emphasized the city IT department is conducting a full cybersecurity review of Flock and that Flock has cooperated with that review.

Council members asked detailed questions about how audits will verify the accuracy of reason codes, how the department will evaluate external agencies’ search requests, and what sample sizes auditors will review. "With the inclusion of that additional information, we will be able to take a sample of all of the searches that are completed and actually search and pull up the specific case report number to make sure that the search ... is in fact related to that specific case," the chief said. He said staff will train the new auditors in a step‑by‑step process and provide written guidance for each audit.

Councilors also raised the public‑engagement question: whether to hold a community meeting on ALPR and the department’s use of Flock cameras. Staff said they updated an online FAQ and made presentation materials available; communications staff Connie reported the web page had 675 visits and social posts reached roughly 15,800 impressions but, to date, the online question form had yielded no additional submissions. Several council members urged arranging a dedicated forum so residents could speak directly to council before the contract renewal date.

Next steps: staff said the current Flock contract expires June 3 and that renewal costs are included in the department’s 2026 operational budget; the department plans to renew the service but will continue to evaluate alternatives and can cancel with 30 days' notice. Council also asked staff to follow up with other agencies that require case numbers to understand how those policies affect investigative operations.