Crime Tech That Spots Gunshots

L O S   A N G E L E S, July 5 -- In big cities, reports of crime and gunfire don’t bring the police to their feet as quickly as they should.

Now, thanks to a developing technology called Shotspotter, police can figure out exactly where a gun was fired. And they can do that faster than a panicky person’s fingers can dial 911.

“We’d drive around the neighborhood [and] we wouldn’t know, ‘Does this guy have the gun’?” said Deputy Thomas Fortier of the Los Angeles County Police Department. “Here, a gunfire event has occurred at this particular location about six to eight seconds before the dispatcher saw it here, and then the dispatcher can come over and play the sounds of that event.”

Now, technology tells the police when something’s going on, even when residents won’t. This system combines cutting-edge acoustic technology with computer programs used by nuclear power plants to track gunshots down, and possibly stop them.

Spotting Shots

Shotspotter consists of eight microphones, scattered on rooftops and utility poles, eight per square mile. Sharp, loud noises activate the microphones, which triangulate the location of the noise by comparing when they received the sound and how loud it was when it reached each microphone. They’re accurate to within about 40 feet, according to Los Angeles County Sherriff’s Deputy Darren Harris.

“We’re fascinated,” says Lt. Sid Heal, the officer in charge of the program. “We’re detecting things we never knew existed. Thirty percent of the gunshots are coming from one house. We think we’ll get a dramatic reduction.”

Once the location has been identified, the system can also be used to identify a surrounding area and call every resident, asking for information.

In Willowbrook, Calif., a neighborhood of one-story homes in Los Angeles County, near Watts and Compton, residents hear plenty of loud noises. One resident, retiree Martha Blaine has heard so many in recent days that she doesn’t bother to report them to police.