The gunshot detection technology ShotSpotter rarely leads Chicago Police Department

The gunshot detection technology ShotSpotter rarely leads Chicago Police Department (CPD) officers to evidence of gun-related crimes and is used to justify over-policing in the primarily Black and brown communities it has been deployed to, according to a report released Tuesday by a city watchdog.

The City of Chicago Office of Inspector General’s (OIG) Public Safety section analyzed CPD and emergency management data between the beginning of 2020 and this May and found that only 9.1 percent of dispatches by the technology resulted in evidence of a gun-related criminal offense.

Among the 50,176 dispatched alerts in that time frame, only 1,056 appeared to indicate that an investigatory stop was the direct result of ShotSpotter.

“Our study of ShotSpotter data is not about technological accuracy, it’s about operational value,” Deputy Inspector General for Public Safety Deborah Witzburg said in a statement.

“If the Department is to continue to invest in technology which sends CPD members into potentially dangerous situations with little information — and about which there are important community concerns — it should be able to demonstrate the benefit of its use in combatting violent crime,” she added. “The data we analyzed plainly doesn’t do that.”

CPD is ShotSpotter’s largest customer, having signed a three-year contract worth $33 million in August 2018. The city quietly exercised an option to extend the contract through Aug. 19, 2023, despite protests calling for its cancellation. The secret extension has drawn scrutiny from Chicago’s City Council.

ShotSpotter’s sensors are deployed over 117 square miles of the city, spanning the 12 police districts with the highest proportion of Black and Latino residents.

The technology has come under increased scrutiny since officers dispatched by it killed a 13-year-old named Adam Toledo.