Gunshot Detection System Wastes N.Y.P.D. Officers’ Time, Audit Finds

ShotSpotter, a system the Police Department uses to detect gunfire, is overwhelmingly inaccurate and leads officers to spend hundreds of hours each month investigating nonexistent shots, according to an audit the New York City comptroller released Thursday.

The Police Department has spent more than $45 million on ShotSpotter since it started using it in 2015, even as cities around the country have stopped using the system. New York must decide before December whether to renew its contract with SoundThinking, the California company that owns the system, and the audit advises officials to decline until the system can be fully evaluated.

Auditors studied ShotSpotter’s accuracy over several months in 2022 and 2023. When it was performing at its best, only 20 percent of ShotSpotter’s alerts actually revealed shootings, they found. Often, it did even worse. Of the 940 alerts officers responded to last June, only 13 percent corresponded to confirmed shootings.

And in 2022, the audit found, the system also failed to detect more than 200 real incidents of gunfire in Manhattan.

The Police Department “is wasting precious time and money on this technology and needs to do a better job managing its resources,” the comptroller, Brad Lander, said in a statement. “Chasing down car backfires and construction noise does not make us safer.”

Several major cities have moved away from ShotSpotter in recent years and others are grappling with whether to renew contracts that will expire this year. Chicago’s mayor campaigned on a promise to jettison the technology and blamed it for the death of an unarmed 13-year old shot by officers responding to an alert in 2021. In Boston, the mayor and police department are on the defensive after three members of the state’s congressional delegation signed a letter that called for a national probe into the system.