Law-enforcement technologyShotSpotter helps Washington, D.C. police track gunshots

Law enforcement officers in Washington, D.C are better equipped to track and monitor gunshots in the city’s most violent neighborhoods by using rooftop sensors which recognize sounds from gunfire.

ShotSpotter technology was developed in the early 1990s acoustic sciences expert Robert Showen, who teamed up with scientists at the U.S. Geological Survey who were working to apply earthquake location systems to gunfire

 After successful experimentation, the first ShotSpotter system was deployed by police in Redwood City, California. Contracts for the device followed in Los Angeles County and Glendale, Arizona. Sixty-five police agencies use ShotSpotter in the United States, along with police in Rio de Janeiro.

The Washington Post reports that law enforcement officials can track shooting incidents and also predict locations and time of future shooting incidents by analyzing records provided by ShotSpotter. The Los Angeles County Sheriff’s department reported that a murder occurred every twenty-nine hours in Los Angeles County in 2008. ShotSpotter allows police to respond to incidents especially in areas where locals fail to contact police after a shooting incident. “We’ve had numerous cases in which we’ve actually found victims laying there bleeding from gunshot wounds,” Los Angeles County Sheriff’s Deputy Chris Kovac  told  ABC Los Angeles. “We’re able to medically treat them, solely based on this alert. If we wouldn’t have been notified via this ShotSpotter system, there’s a good chance some of these people would’ve died,” said Kovac.

The Post notes that police in Washington, D.C. adopted ShotSpotter in 2005 following a federal grant of $2 million to place sensors across the 7th Police District in Southeast Washington. “The 7th District was selected for ShotSpotter because it led the city in homicides,” said Joel Maupin, who was police commander of the district.

ShotSpotter enables officers to respond to shootings more quickly, and it also validates claims of gunfire from local residents, since ShotSpotter can distinguish between sounds from a gunshot and backfire from vehicles. “ShotSpotter gives you a specific location,” said Kristopher Baumann, president of the D.C. police union. “You can go there and get out of the car. You can find a victim or shell casings.”

Washington, D.C. expanded ShotSpotter to six of the seven police districts and the network now covers about one-third of the city. The Post reports that Washington, D.C. has spent about $3.5 million to maintain and expand the system, which now operates at least 300 acoustic sensors across twenty miles of the city. Since its installation, ShotSpotter has recorded 39,000 separate incidents of gunfire, according to an analysis by the Post. Concentrated in the eastern half of Washington, D.C., the ShotSpotter network has captured 18,700 incidents in Southeast, 10,600 incidents in Northeast, 6,400 incidents in Northwest, 1,600 incidents in Southeast, and an additional 1,600 shooting incidents along the edges of the city.

In 2009 alone, ShotSpotter captured more than 9,000 incidents of gunfire in Washington D.C. That figure has decreased by 40 percent in recent years, following a reduction in homicides rates. In Washington D.C.’s Northeast, the neighborhood surrounding Clay Terrace has witnessed 302 shooting incidents between 2008 and November 2013. Shooting incidents peaked at 129 in 2009, but dropped to seventeen incidents in 2012.

Greg Stewart, a neighborhood resident who serves on the local Advisory Neighborhood Commission, is aware of the ShotSpotter network and noted the change. “Right now, you don’t really hear complaints,” said Stewart. The city’s Northwest has limited ShotSpotter coverage and a targeted portion of the area experienced 299 shooting incidents between 2008 and November 2013. Shooting incidents peaked at ninety-nine in 2009 but dropped to forty-six last year.

When ShotSpotter does occasionally miss a shooting, a rigorous review is initiated by law enforcement. Circumstances that may escape detection from sensors include the use of silencers or when shots are fired into a vehicle and the vehicle absorbs the acoustic energy of the gun blast. The same is true for “execution style” shootings in which the gun is inches away from the victim. “We don’t offer a 100 percent ironclad guarantee to capture 100 percent of all the shootings,” said Ralph Clark, ShotSpotter’s chief executive. “What we provide is a lot of gunshot intelligence that otherwise would not be attainable by any agencies.”

ShotSpotter in Washington, D.C is linked to a network of closed-circuit cameras which provides law enforcement real time footage of covered areas. The location and appearance of ShotSpotter sensors are not publicized to guard against vandalism. ShotSpotters sensors are wrapped in weatherproof containers roughly the size of a watermelon and each sensor includes microphones, hardware, software, and a GPS linked clock which provides law enforcement precise times and locations.