Police opened fire in Plainfield this week to test out a new ShotSpotter system, a set of highly sensitive audio-sensors that pinpoint the location of the shot.

Tom O’Reilly is the Executive Director of the Police Institute at Rutgers. He says these systems help officers get to the scene faster than waiting for a 9-1-1 call.  

“They help gather evidence and in many cases are a significant plus in terms of apprehending the individual who’s doing the shooting.”

Paterson, Irvington, East Orange, and Newark all have ShotSpotters, but it hasn’t worked everywhere. Earlier this year, officials in Trenton stopped an expansion of its gunshot detection program after several false alarms and one device failed to detect a shooting just blocks away.

O’Reilly says like any technology, there are always kinks to work out.

He says they’re a helpful tool at a time when police departments are tightening their belts.