Crime Tech That Spots Gunshots

L O S   A N G E L E S, July 5, 2000 -- 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.

“I’ve heard some shots, all right. But I just considered, maybe it’s coming up to the Fourth of July ... maybe it was the fireworks, ”Blaine said.

In a six month experiment, the Los Angeles County Sheriff’s department installed Shot Spotter in an area where they had a lot of gunfire. But they found out there is much more than they thought: Only one in ten gunshots incidents are reported by the public.

“In about ten weeks we have confirmed about 260 confirmed gunshots in one square mile,” Heal said.

Officers listen to a sound bite of the sound to pick out which are gunshots and which are firecrackers. The gunshots then show up on a map that officers can print out and use to track down the culprits.

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

Los Angeles isn’t the first area to use the Shotspotter system from Los Altos, Calif.-based Trilon Technologies, but they’re the first to combine it with callback features used by nuclear power plants and tornado-warning services. Police circle houses near the gunshot on a computer, which then calls all the residents of those homes, asking them to call the cops and tell them about the noise.

Finally, the callback system from Dialogic Communications in Franklin, Tenn., gives officers an aerial photo of the gunshot location.

“You can see as you zoom in if that’s a street, a house, a side yard or a front yard where the gunshot came from,” says Dave Krikac, a vice president of marketing at Dialogic.

Testing, Testing

Unfortunately, Shot Spotter has been slow to catch on, and it has not been that useful for convicting criminals.

The program is also supposed to function as a deterrent, so the shooters know police are listening. But although police officials say they spread the word with meetings and flyers, there hasn’t been much awareness in the community of Shotspotter, says Glenda Wina, spokeswoman for Los Angeles County Supervisor Yvonne Burke. None of the longtime Willowbrook residents spoke to said they were aware of the project. They liked the idea once they’d heard about it.

“I approve of that very much. There’s a lot going on that we don’t know about,” said retired Willowbrook resident Burdette Harris.

But Shotspotter may fail in Los Angeles; it’s run out of money. Police need to continue the test and they’ve used up the funding, Heal said. Police are asking politicians for more money and if the department doesn’t find any by June 30, he said, they’re going to have to take the project down. The system would cost $85,000 to run for the next six months.

Not everyone is sold on the new technique, particularly privacy experts who worry that the microphones could be listening into to more than they should.

Any technology which records civilians without their permission must be looked at skeptically, says James Love, director of Ralph Nader’s Consumer Project on Technology.

“What’s surprising is that it’s a rather extensive deployment for something that hasn’t resolved into too much law enforcement activity—but a lot of data is being collected,” he said.

But Heal and privacy advocate Simson Garfinkel, author of Database Nation say the system is designed to assuage some concerns. The microphones can’t pick up conversations, only ‘acoustical spikes’ like gunshots, truck backfires, and loud, sharp screams. They only record for eight seconds at a time. And the police are being open about this surveillance tool, rather than hiding it from the community — a plus in Garfinkel’s eyes.

The key is to keep the data open to the public, Garfinkel says.

“We have very few protections with what is done with the information once it is obtained. We should have access to that database of gunshots,” he said.

Eyes on You

For the future, maybe Americans should look to England, where civilians are under almost constant surveillance.

“We have cameras everywhere, absolutely everywhere. We rely very heavily on [closed circuit] TV as a crimefighting tool,” says Alex Hathaway, spokeswoman for London’s Metropolitan Police.

London has done Willowbrook one better. In the high-crime borough of Newham, an advanced facial-recognition computer system continually scans through surveillance images for pictures of wanted criminals. When it comes up with a good match, it tells police to check the tape.

The police have no monopoly on video cameras in London. Local city councils run cameras. Shops put cameras in their doorways. Britons are constantly being watched. According to Hathaway, that makes them feel safer.

“The received wisdom is that CCTV [closed-circuit television] cameras in town centers do bring crime down, because people know they’re being watched,” she said.