How much ALPR retention is enough?

The question

What retention window balances investigative utility against privacy for license-plate readers — and who should decide (vendor default, city council, state cap)?

Why it matters

Flock shifted default 30→7 days claiming ~90% of crimes solve within a week (CEO-claimed aggregate). States already diverge (NJ five years, CA max, WA 21 days per Langley). Democratic legitimacy and vendor defaults interact.

What we currently believe

Open. Langley's 90%/seven-day figure is single-source, not independently verified here. Do not close.

Evidence we have

• garrett-langley in 2026-08-18-all-in-podcast-flock-ceo-garrett-langley-on-controversy: "we think 90% of crimes will get solved within seven days of data retention."
• garrett-langley in 2026-08-18-all-in-podcast-flock-ceo-garrett-langley-on-controversy: "city councils should have that final say."

Evidence we need

• Independent solve-rate studies by retention bucket.
• Abuse rates vs retention length (beyond Langley's audit anecdotes).

How to resolve

Publish or cite law-enforcement data sets with retention policy metadata; compare cities that changed defaults.

Related

• license-plate-retention-privacy-vs-safety
• alpr-retention-default-to-democratic-crime-solve-tradeoff
• flock-safety