Short answer
Each agency that uses Flock sets its own retention period, within any limits in state law. Flock recommends 7 days, though agencies that already had an approved period kept it. Many published policies set 30 days. After that, Flock says the data is permanently deleted unless it was preserved as evidence for an investigation.
Who decides
Flock says the customer “sets its own data retention period, based on its own policy and applicable law.” In August 2026, Flock lowered its recommended default from 30 days to 7. Existing customers kept the periods already approved in their jurisdictions.
State law can cap it. Knoxville’s police policy, citing Tennessee law, says captured plate data “shall not be stored for more than thirty (30) days” unless it is part of an ongoing investigation. Other states set different limits or none.
When data is kept longer
Data preserved as evidence for an investigation is kept past the normal period. Flock’s Evidence Mode lets investigators preserve specific records before they would otherwise be deleted. Everything else is deleted on schedule. That’s why the records in a case are usually only the ones police chose to keep, and why defense preservation requests should come early. See requesting ALPR records in discovery.
How to find out for a particular agency
- Look for the agency’s published ALPR policy.
- Check whether the agency has a Flock transparency portal. Flock says more than 1,500 agencies have published one showing retention periods.
- If you have a pending case, ask your attorney. The policy in force on the relevant date is what matters.
For more on retention, preservation and sharing, see ALPR data retention and sharing.
Law varies by state. State constitutions, statutes and courts may treat this issue differently from federal law. A licensed attorney in your jurisdiction can tell you how it applies.
Sources
- VendorFlock Safety, “How Flock Protects” (data privacy and trust page)Accessed 2026-11-05
- SecondaryPolice1, “Flock Safety sets 7-day default for ALPR data, adds mandatory misuse safeguards”August 14, 2026
- PolicyKnoxville Police Department, General Order No. 4.26, “Automatic License Plate Readers”Revised July 28, 2026 · ¶¶ 15, 27, 29–30
Related
- ALPR Data Retention and SharingHow long license plate reader data is kept, who decides, how records are preserved, and how widely agencies share ALPR data, with Flock, Tennessee and California examples.
- Requesting ALPR Records in DiscoveryHow the defense obtains license plate reader records: Rule 16, Brady, subpoenas, what to ask for, and why preservation requests need to come early.
- What Data License Plate Readers CollectThe records an ALPR system like Flock creates: plate images and reads, vehicle characteristics, timestamps, locations, hotlist alerts, search logs, and how long they're kept.