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Denver police want to expand ShotSpotter gunshot detection system

December 04, 2015

The Denver Police Department wants a half million dollars to expand a system that pinpoints gun shot locations for officers on the street.

Police officials on Monday will ask City Council to approve a one-year, $525,000 contract with ShotSpotter, a California-based company that developed the technology, according to a resolution request attached to Council's Monday meeting agenda.

The police department installed ShotSpotter in January through a partnership with the U.S. Bureau of Alcohol, Tobacco and Firearms. It covered a few square miles in the city, but police have kept the exact locations a secret, saying they did not want to tip off criminals.

The proposed expansion would triple the amount of territory covered by the system, said Capt. Steven Carter, who manages ShotSpotter.

The department analyzed data collected over the past year, determined the system was useful and decided to spend its own money on it for another year, Carter said.

Since mid-January, ShotSpotter has recorded 425 gunshot alerts, involving 1,472 rounds, Carter said. Police have made 29 arrests directly tied to Shot Spotter and captured 16 guns.

ShotSpotter uses acoustic sensors mounted on buildings to detect gunshots. Computers analyze sounds and then send suspected gunshots to human operators who verify the reports and then relay the location to patrol officers.

All of this takes less than a minute with patrol officers arriving about 38 seconds after the first shot is reported, Carter said.

The system can tell the difference between gunshots and other loud noises such as firecrackers or garbage bins clanging.

ShotSpotter guarantees it can pinpoint a gunshot's location with 82 feet, but Denver police are finding it much more accurate, he said.

In the past, a resident might call about gunshots in a neighborhood but it could be hard for officers to figure out where the shots had been fired because of the way noise travels, Carter said.

Just hours after installing the system in January, it helped police nab three suspects in a shooting.

Denver police and federal law enforcement officials have used ShotSpotter to combat gang violence. Investigators are able to find shell casings, which can help investigators link guns to multiple crimes.

Even though Shot Spotter provides an accurate location, police still want residents to dial 911 when they hear gunshots.

"People calling into us is hugely important," Carter said. "ShotSpotter is not a witness. It doesn't see cars. It doesn't describe a bad guy's clothing."

Even if police don't catch the bad guy, their presence in neighborhoods send a message that gun crime is serious, Carter said.

"We get the message out we are taking this stuff seriously and we are trying to figure out what is going on," he said.

Denver Post