BALTIMORE - Someone fires a gun on a violent street in Baltimore...
Officers will hear about it with the help of a new crime-fighting tool -- the ShotSpotter, a system that uses a network of microphones and cameras to detect gunfire and alert police.
Police say it’s unlike anything they’ve used before in city.
THURSDAY @ 11 p.m. ABC2 NEWS gets an inside look at what ShotSpotter will do in Baltimore.
More than 70 jurisdictions in the country have the technology, according to ShotSpotter’s website.
In Minneapolis, the police department has been using the technology for about eight years, said Sgt. Mark Koenig of the department’s business and technology division.
In 2013, the devices, which cover about three square miles, reported 1,058 incidents. Koenig said 232 reports were for single gunshots or fireworks; before the system got an upgrade late last year, the devices picked up fireworks as possible gunfire. The remaining incidents were reports of multiple gunshots.
The biggest benefit, Koenig said, is having independent evidence to show where shots might have been fired, he said. The reports are routed through a central dispatch system now, but later this year, Minneapolis police officers will be able to pick them up in their cars.
“If we go out and people tell us there were no gun shots, then we find casings in the street, we know someone wasn’t telling us the truth,” Koenig said.
In Milwaukee, which has been using ShotSpotter for several years, the police department did a study that found as few as 14 percent of residents were likely to call 911 for gunfire, said Lt. Mark Stanmeyer, department spokesman. That’s either because they’ve grown desensitized to it, or they’re afraid of retaliation, he said.
Stanmeyer said there was concern from residents who feared the microphones would be used to listen to their conversations. The system, though, doesn’t get activated until it hears a suspected gunshot.
“Could people be having a conversation and it picks up something? It could,” he said. “But it’s not like Big Brother is listening to conversations in the neighborhood.”
ShotSpotter covers three and a half square miles in Milwaukee and the city is trying to get funding to cover another three square miles, Stanmeyer said.
The technology has been used in smaller cities, too.
The police department in Wilmington, N.C. got a $300,000 federal grant in 2011 to install ShotSpotter over three square miles, said Capt. Jim Varrone of the department’s administrative services bureau. The city, with a population of 108,000, is planning to expand ShotSpotter over another three square miles this year.
It costs about $140,000 per year to maintain. Last year, police responded to 408 gunfire alerts.
“It’s not a silver bullet to a problem,” Varrone said.
But it allows officers to immediately jump on an incident rather than waiting for someone to call 911, he said.
The police department in Trenton, N.J.—population 85,000 -- installed ShotSpotter in 2010, but discontinued its use this year because of ongoing financial problems in the city.
Lt. Mark Kieffer, who works in the criminal investigations bureau of the city’s police department, said the technology works if there’s the right infrastructure in place.
“You need a good video camera system, and we never really had that,” Kieffer said. “If you have that, it’s excellent.”
There were some issues with false positives. For example, ShotSpotter would detect sounds from car crashes or dump trucks dropping off loads at the city recycling center. Initially, police dispatchers were sending officers every time there was a report of gunfire, and sometimes it turned out to be nothing at all.
ShotSpotter was good about sending technicians to recalibrate the devices to cut down on these problems, Kieffer said.
“It doesn’t happen a lot, but you have to work the system a little bit,” Kieffer said.
Koenig said false alarms were more common before the technology was upgraded. Now, the reports are filtered directly through ShotSpotter’s headquarters in California, where technicians who are trained to listen to the noise and decide whether it’s actually gunfire or something else.
Varrone said false alarms could be a problem on Fourth of July and New Year’s Eve, when people are shooting off fireworks. During those times, the system can be put into a suppression mode to avoid picking up these sounds.
“The system is not 100 percent perfect,” Varrone said. “But it’s pretty good.”