Antioch Police | Gunshot detection
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.
At a glance
- How an alert is handled
- Corroborated activations are dispatched as Priority 1 calls; uncorroborated ones may be set to Priority 2 case by case [1]
- Monitoring
- At least two communications centre staff log in and monitor activations at all times [1]
- Required reporting
- Monthly and yearly updates counting founded and unfounded activations, community-reported gunfire calls, rounds fired with locations and dates, and significant cases [1]
- Follow-up
- Officers canvass the area; the policy says follow-up should include probation and parole searches when appropriate [1]
- Camera integration
- When practical, staff should use the public safety cameras with the alert to locate people or vehicles leaving the scene [1]
- Aerial support
- The policy lists requesting an air unit or drone support as an option when appropriate [1]
- Records requests
- The policy says the data is proprietary to the vendor and routes all requests to the programme manager [1]
- Sensor locations and count
- not in the policy, which refers to audio sensors placed in selected areas without saying where or how many [1]
- Published activation counts
- the policy requires monthly and yearly counts. We did not find them and did not sweep for them, so this is an open question rather than a finding that they are missing [1]
How it happened
- Context
Policy 344 carries a November 2024 stamp
The department's policy manual carries a Lexipol copyright stamp of November 26, 2024. Policy 344 governs the use of ShotSpotter, named in the policy as SoundThinking technology. [1]
What the policy establishes
Antioch’s manual carries a dedicated chapter on gunshot detection, Policy 344, which is unusual. Most departments that run this technology govern it through general dispatch or evidence policies. The chapter carries a Lexipol copyright stamp of 26 November 2024.[1]
The system is described as “audio sensors placed in selected areas to identify the location of gunfire”, relayed immediately to the communications centre and to officers’ mobile computers, phones and tablets.[1] The communications centre supervisor “should ensure at least two personnel will log in and monitor ShotSpotter activations at all times”.[1]
Alerts are dispatched by priority. Activations “corroborated by witness or officer accounts, shall be categorized and dispatched as Priority 1 calls”, while uncorroborated activations “may” be categorised as Priority 2 “as necessary and on a case-by-case basis”.[1]
What follows an alert
Two provisions describe what an acoustic alert sets in motion. On canvassing, the policy says “canvasing should be completed by the dispatched officers” and that “follow up should include probation and parole searches when appropriate”.[1] On cameras, “when practical, dispatchers and/or officers, should attempt to use incoming ShotSpotter activation information and the public safety cameras to locate suspects/vehicles leaving the scene and broadcast information to responding units”.[1] The policy also lists requesting “an Air unit or UAS drone support” among the options when appropriate.[1]
A microphone that hears a bang can therefore bring officers, cameras and an aircraft to a neighbourhood, and can prompt searches of people already under supervision there. That is the system as the department describes it, and it is a reason the accuracy figures below matter.
The measurement the policy already requires
Policy 344 tells the crime analysis unit to produce monthly and yearly programme updates including “the number of founded and unfounded ShotSpotter activations received”, “the number of gunfire-related calls reported by the community”, “the number of rounds fired, locations, and dates”, and a summary of significant cases initiated or supplemented by the system.[1]
Founded against unfounded, next to the number of times residents called in gunfire themselves, is close to the ideal public measure of whether this technology earns its place. The department’s own policy says the numbers are produced. We did not find them published and did not sweep for them, so we make no claim that they are unpublished.
What the record does not establish
Where the sensors are, how many there are, what the contract costs and how long it runs. The policy states that “ShotSpotter data is proprietary to the vendor” and routes records requests to the programme manager.[1] The Atlas of Surveillance snapshot in this repo separately records gunshot detection at this department.[2]
Where to ask
Ask for the monthly and yearly programme updates by the name the policy gives them. That request is specific, the documents are described in a published policy, and the answer would tell residents how often the system is right. Ask the council for the contract and its cost at renewal time. Antioch City Council meets in public and takes comment.
Questions
- What does gunshot detection actually do?
- The policy describes audio sensors placed in selected areas that identify the location of gunfire and relay it to the communications centre and to officers' mobile computers and phones. An alert is treated as a report of shots fired at a location and dispatched accordingly. [1]
- What happens in my neighbourhood after an alert?
- Officers respond and canvass the area, and the policy says follow-up "should include probation and parole searches when appropriate". When practical, staff are directed to use the public safety cameras alongside the alert to locate people or vehicles leaving the scene, and to request air or drone support where appropriate. An acoustic alert therefore has consequences beyond the response itself. [1]
- Does anyone count how often the alerts are wrong?
- The policy requires it. The crime analysis unit must provide monthly and yearly updates including "the number of founded and unfounded ShotSpotter activations received" and the number of gunfire calls reported by the community. Those two figures side by side are the most useful measure of whether the system works. We did not find the reports and did not sweep for them. [1]
- Can I get the underlying data?
- The policy makes that harder than usual. It says "ShotSpotter data is proprietary to the vendor" and routes all public records requests to the programme manager. A vendor's claim over data does not by itself decide a public records question, but it does mean requests take longer and may be contested. [1]
What we do not know
- The monthly and yearly counts of founded and unfounded activations the policy requires.
- Where the sensors are and how many there are.
- The contract, its cost and its term.
- How often a probation or parole search follows an activation.
What you can do
Show up
Systems like this one are approved by boards, councils and committees that meet in public. We have not yet confirmed where each of them meets in Contra Costa County.
What we have documented in Contra Costa County →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 →Sources
- 1. Antioch Police Department Policy Manual, Policy 344, ShotSpotter · Primary document · accessed · archived copy
- 2.
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