Audio Analysis: Getting a Jump on Gun Violence
New York Times
By ELIZABETH SVOBODA
Published: May 11, 2009
Around 2 a.m. on March 8, 2008, officers at the East Palo Alto, Calif., Police Department received a computer alert. Barrages of gunshots had just been fired in the 2100 block of Capitol Avenue and nearby at the corner of University Avenue and Bell Street. Driving down Bay Road toward University Avenue, the sergeant who responded spotted a dark sedan pulling away at breakneck speed.
As the officer gave chase, he asked other local departments to help surround the fleeing sedan. Within minutes, the three occupants of the getaway car were surrounded: Chester Best, Stoney Gipson and Oliver Ware — all gang members, the police say. They were charged with resisting arrest, possessing firearms and evading an officer in a vehicle.
Such captures might seem all in a night’s work, but according to the East Palo Alto police chief, Ron Davis, this particular coup would not have been possible if not for an innovation in audio surveillance technology. In 2007, East Palo Alto installed the ShotSpotter Gunshot Location System, which consists of a network of rooftop acoustic sensors that capture gunshots and determine, within seconds, where they were fired. The system contains sophisticated digital filters that allow it to record gunfire and ignore other loud noises, so false alarms are relatively rare. The seconds or minutes that the police gain from receiving gunfire information in close to real time, Chief Davis said, can make the difference between catching suspects and letting them get away.
“When you look at a regular gunshot call for service, a person has to hear the shot, guesstimate where the shot is coming from, and by the time they get to the 911 relay, there’s a two- to-three-minute delay,” he said. “That makes it 99.9 percent unlikely that the call will result in any arrest.” In the March case, he said, “If we would have waited for the call, the car would already have been over the Dumbarton Bridge into Newark.” Two of the three men arrested that night are in police custody and awaiting trial.
A version of this article appeared in print on May 12, 2009, on page D5 of the New York edition.
Erin Lopez |
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