New York

A New NYPD Gunfire-Detection System Is Coming to a Neighborhood Near You


New York Police Department commissioner William Bratton and Mayor Bill de Blasio announced Monday that the department would expand its use of a hi-tech crime-fighting tool designed to automatically detect the sound of gunfire.


The two-year pilot program, announced at a press conference at NYPD headquarters, will bring the technology, known as ShotSpotter, into use in seventeen precincts, with plans for expansion down the road.

The ShotSpotter system relies on a series of listening devices spread out across an area targeted for monitoring. When a microphone picks up the distinctive sound of gunfire, the stations triangulate the location of the shot — within an impressive-sounding 25 meters — and send an alert to a central database. After the alert is reviewed by an analyst, it’s passed to officers in the field, and cameras incorporated into the listening station can be activated for a nearly immediate, real-time view of the area.

The limited rollout will involve 300 devices that will be installed across fifteen square miles in various precincts in the Bronx and Brooklyn that contain known crime hotspots. Bratton said the cost for the first year was about $1.5 million. (In years past, Bratton served as a paid member of California-based ShotSpotter’s corporate board, resigning when he returned to once again head the NYPD in 2013.)

A ShotSpotter commercial released in October

When ShotSpotter works properly, it can alert law enforcement to gunfire even when no emergency call is made. But the system, which is currently in use in several other large American cities, has been reported as inaccurate with false positives. In fact, as the department’s deputy commissioner for information technology, Jessica Tisch, noted, the NYPD tried out similar technology in 2011. At the time, though, the system was so inaccurate as to be ultimately useless.

“We had so many false positives that it became, for lack of a better word, noise,” Tisch said. Part of ShotSpotter’s services include screening all alerts before they go to department dispatchers, an attempt to filter only genuine results. The ShotSpotter system also requires a shot to be heard by three listening stations, another safeguard against false positives.

De Blasio said that for residents of some of New York’s neighborhoods, gunshots are a “sad soundtrack to their lives.” Broad crime trends have continued to decline, but there have been 185 shootings already this year, up from 166 by this time in 2014, an 11 percent increase. (It’s a rise that Bratton, earlier this month, bizarrely seemed to attribute to the legalization of marijuana in Colorado and Washington.)

But as Bratton noted, as much as 75 percent of gunfire is never reported, for various reasons, so ShotSpotter may be able to provide a more accurate count of exactly how much gunplay goes down on New York City streets. Bratton also noted the possibility of using the system to predict violence; if shots are detected in a neighborhood associated with a particular gang, for example, police may be able to anticipate a retaliatory strike coming on a rival’s home turf.

De Blasio said he expected that, by being able to respond to shootings even before a 911 call comes in, the system would eventually have a deterrent effect.

“This is going to be a whole new ballgame,” de Blasio said. “The bad guys in this town are going to get the message that if they fire their weapon, the police will know instantly.”

There have been some privacy concerns raised about ShotSpotter in other jurisdictions. The American Civil Liberties Union, for example, in 2012, pointed to a case in Massachusetts in which police sought to use audio recordings of a street fight that ended in gunfire as part of their case against the shooter. As ACLU senior policy analyst Jay Stanley wrote at the time, referring to a New York Times report, “if the courts start allowing recordings of conversations picked up by these devices to be admitted as evidence, then it will provide an additional incentive to the police to install microphones in our public spaces.”

Post by NYPD

Email Jon Campbell at


Most Popular