It’s Time for Police to Stop Using ShotSpotter

by Matthew Guariglia

Matthew Guariglia is a policy analyst working on issues of surveillance and privacy at the local, state, and federal level. He received a PhD in history at the University of Connecticut where his research focused on the intersection of race, immigration, U.S. imperialism, and policing in New York City.

Court documents recently reviewed by VICE have revealed that ShotSpotter, a company that makes and sells audio gunshot detection to cities and police departments, may not be as accurate or reliable as the company claims. In fact, the documents reveal that employees at ShotSpotter may be altering alerts generated by the technology in order to justify arrests and buttress prosecutors’ cases. For many reasons, including the concerns raised by these recent reports, police must stop using technologies like ShotSpotter.

Acoustic gunshot detection relies on a series of sensors, often placed on lamp posts or buildings. If a gunshot is fired, the sensors detect the specific acoustic signature of a gunshot and send the time and location to the police. Location is gauged by measuring the amount of time it takes for the sound to reach sensors in different locations.

According to ShotSpotter, the largest vendor of acoustic gunshot detection technology, this information is then verified by human acoustic experts to confirm the sound is gunfire, and not a car backfire, firecracker, or other sounds that could be mistaken for gunshots. The sensors themselves can only determine whether there is a loud noise that somewhat resembles a gunshot. It’s still up to people listening on headphones to say whether or not shots were fired.

In a recent statement, ShotSpotter denied the VICE report and claimed that the technology is “100% reliable.” Absolute claims like these are always dubious. And according to the testimony of a ShotSpotter employee and expert witness in court documents reviewed by VICE, claims about the accuracy of the classification come from the marketing department of the company—not from engineers.

Moreover, ShotSpotter presents a real and disturbing threat to people who live in cities covered in these AI-augmented listening devices—which all too often are over-deployed in majority Black and Latine neighborhoods. A recent study of Chicago showed how, over the span of 21 months, ShotSpotter sent police to dead-end reports of shots fired over 40,000 times.

Read entire article at Electronic Frontier Foundation