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How Does ShotSpotter Differentiate Between Gunshots And Fireworks?

June 28, 2017

SACRAMENTO (CBS13) — The Fourth of July is coming up, and that means fireworks will soon be going off, and many of those explosions will likely register on Sacramento’s ShotSpotter system— its technology that detects gunfire in parts of the city. But police say it won’t be an issue because the technology has the sound of a gunshot down to a science.

In the coming days, the sounds of freedom will be ringing all over Sacramento. As fireworks go off, the city’s ShotSpotter gunshot detection system will be on overdrive, so how will it know the difference between gunfire and a firework?

Sacramento Police Sgt. Matthew McPhail said, “The system is designed to look at the very specific electronic signature almost like an EKG or a heart meter.”

ShotSpotter technology covers a six-square-mile section of the city, installed in both North and South Sacramento. Sensors can pick up the sounds of gunfire at the exact location it occurs. It then sends alerts directly to patrol officers. But, on holidays like the 4th of July, loud explosions from illegal fireworks can clog up the system. Sacramento police officers it’s not a big problem.

“The system is designed to be able to differentiate between sounds of gunfire from the sounds of other similar sounds like fireworks,” said McPhail.

To the human ear, it can be hard to tell the difference between the sound of a gunshot and an illegal firework, but shot spotter officials say the technology, which measures distance, direction and wavelengths of sounds, can.

ShotSpotter President & CEO Ralph Clark said, “We developed machine algorithms that use classification work that again distinguish things that are clearly gunshots.”

Police say if there’s an instance where the sound picked up by ShotSpotter is questionable, they will always air on the side of caution and respond. Police say safe and sane fireworks will not register on the ShotSpotter system.

CBS, 4th of July: Sacramento