California
Contra Costa County
On record
Checked 20 Aug 2026- Technologies
- 3
- Systems
- 6
- Devices mapped
- 594
Contra Costa County, California. Device data © OpenStreetMap contributors (ODbL), with community reporting via DeFlock. Open the full map →
Contra Costa County’s research pass read four plate reader policies and found four different answers on how long the data is kept: thirty days in Richmond, six months in Concord, one year at the county Sheriff, and a minimum of one year in Antioch. It also read Antioch’s gunshot detection policy and its published military equipment inventory, and Richmond’s monthly plate reader statistics, which run back to 2023 and are the fullest published record of plate reader activity we have found in California. The Sheriff’s own website and Vacaville’s answer our tools with access-denied pages, and the Flock transparency portals could not be read; a check by hand found no plate reader policy posted for the Sheriff later than the 2013 revision. Richmond’s readers were offline from November 2025 until a 4-3 council vote in March 2026 restored them through the end of the year, which the pass records from local reporting quoting the department’s own press release and its chief, not from council records we have read. The county has many more agencies than the five covered here, and they were not swept on this pass.
What's in use here
Antioch's plate reader policy keeps data for at least a year and directs officers to canvass plates around homicides and shootings. The chapter carries no immigration or out-of-state clause, where the Richmond policy in the same county does.
The plate reader policy the county publishes was last revised in November 2013. It keeps data for a year, shares it through a regional exchange, allows trained volunteers to operate the equipment, and predates the state law that governs plate reader sharing today.
Concord wrote its own plate reader policy rather than adopting a template. It sets a six month retention limit, requires purging from backups as well as live systems, and lists exactly what an audit record must contain. The posted version is dated January 2016.
Richmond's police chief took the plate readers offline in November 2025 after learning a Flock setting had made the city's data searchable nationwide. The council voted 4-3 in March 2026 to turn them back on through the end of the year. The city publishes monthly statistics throughout.
Antioch's military equipment posting lists six drone models with quantities and unit costs, from a $450 hobby-sized aircraft to a $6,500 thermal model. Every page of the file the city publishes is watermarked as a draft.
Antioch has a dedicated gunshot detection policy, which few departments publish. It requires the crime analysis unit to count founded and unfounded alerts every month, and it sends officers to canvass, with probation and parole searches as follow-up where appropriate.
Who runs it
The agency is the accountability unit: who voted, whose policy applies, and who answers a records request.
| Agency | Jurisdiction | AB 481 policy | SB 34 policy | Systems |
|---|---|---|---|---|
| Antioch Police Department | City of Antioch | On file | On file | 3 |
| Concord Police Department | City of Concord | — | Posted | 1 |
| Contra Costa County Office of the Sheriff | Contra Costa County | — | Posted | 1 |
| Richmond Police Department | City of Richmond | — | On file | 1 |
| 4 agencies on record. A jointly run system counts against each of its operators, so this column is not a county total. "Posted" means the policy is published where the law requires it. "On file" means we hold the document. "Not posted" and "not found" mean we could not find it on the agency's own website on the date shown; they say nothing about how the system is used. An agency with a dash has not been checked, which is not a finding. | ||||
Trackers
Meetings, contracts, records
Nothing listed yet. The trackers launch here, and facts appear only with their sources.
How the inventory works →What you can do
Civic action
Show up
Public comment is open to any resident, and you do not have to be an expert to use it. We have not yet confirmed where the bodies that decide for Contra Costa County meet. How the inventory works explains what we check and how to check it yourself.
How the inventory works →Personal protection
Protect yourself
Practical steps to shrink your personal data trail. Our guides publish at launch; until then, EFF's Surveillance Self-Defense is the best starting point.
Surveillance Self-Defense ↗Get the digest
A regular digest of what changed in the world of surveillance: the counties we published, the devices that appeared on the map, and the public meetings where these decisions get made. We send it when there is enough to report.
One click to unsubscribe. What we do with your address is on the newsletter page.