ShotSpotter technology does little stop gun crime: Chicago watchdog

The gunshot detection technology ShotSpotter rarely leads Chicago Police Department (CPD) officers to evidence of gun-related crimes and is used to justify overpolicing 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.

A spokesperson for the company stressed that CPD “continually describes ShotSpotter as an important part of their operations.”

“We would defer to the Chicago Police Department to respond to the value the department gets from being able to precisely respond to criminal incidents of gunfire,” they added in a statement.

The results of the OIG’s report line up closely with another released earlier this year by the MacArthur Justice Center.

The civil rights law firm found that 89 percent of deployments initiated by the detection technology turned up no gun-related crime over an 18-month period using emergency management data.

ShotSpotter has previously pushed back aggressively against criticism of its accuracy. 

It commissioned an analysis of the MacArthur Justice Center’s report earlier this summer that concluded the data used in the study was “inappropriate” and thus “not a reliable measure” of efficacy.

The company also commissioned Edgeworth to conduct an analysis of its 97 percent accuracy claim, which confirmed it, though ShotSpotter has declined to share the data to back up that claim. 

Local Chicago activists have also argued that even if ShotSpotter is accurate, the way it is placed in overexploited communities and deploys officers prepared for an armed confrontation is dangerous. 

“ShotSpotter doesn’t make me, my friends, or my family safer. It makes us less safe and, in fact, makes us fear for our lives each time a ShotSpotter alert sends a police officer rushing into our neighborhood,” Anderson, a member of the Little Village community where Toledo was killed, said at a protest last month. “If we want to really stop gun violence in our city, the answer isn’t to rely on flawed and costly tech.”

The OIG’s report notes that officer perceptions of the frequency of ShotSpotter alerts may be changing their policing behavior. The report includes a handful of examples of officers using perceived gun violence frequency to justify pat-downs.

—Updated at 3:24 p.m.