Surveillance Technology Helps Boston Police Find Location Of Gunfire

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In October 2007, the Boston Police Department went live with ShotSpotter, an acoustical technology that provides an immediate notification when shots have been fired. Since then a network of electronic ears has been monitoring some of Boston's high-crime neighborhoods, listening for the telltale sounds of gunfire.

Police say the ShotSpotter technology helps improve response time, identify hotspot areas, recover evidence and locate individuals in possession of guns.

But some say funding for the expensive technology is better spent on preventing gun violence in the first place.

An Example Of ShotSpotter At Work

The crime was horrific: five people shot; four of them fatally, including a 2-year-old boy and his mother. The victims were found strewn along a Mattapan street. By the time calls poured into the Boston Police Department, cruisers were already on the way.

The Boston Police Department said the city paid about $1.5 million to install the technology, with annual maintenance costs running $150,000 to $175,000.

The department's first notice of the shooting came through its ShotSpotter.

"In police work, the quicker we can get to a scene the easier it is to identify victims, to talk to witnesses and to collect evidence. ShotSpotter gets us there faster," said John Daley, deputy superintendent of the Boston Police Department. “It tells us precisely where the firearm discharge took place."

ShotSpotter technology was first proposed by Boston City Councilor Rob Consalvo.

"On average, one to two minutes before a calls comes in for a 911 shot, ShotSpotter has picked up the shooter and we’re dispatching a police cruiser and ambulance on the scene," Consalvo said.

In some cases, there have been no calls. The only notification has been ShotSpotter technology, currently a network of more than 100 acoustical sensors deployed over a six-square-mile swath of the city most susceptible to gunshot violence, "from Mattapan Square, through corridors of Mattapan, Dorchester and Roxbury, down to the South End," Consalvo said.

Expanding The Reach Of ShotSpotter

The Boston Police Department said the city paid about $1.5 million to install the technology, with annual maintenance costs running $150,000 to $175,000.

Part of the area under surveillance is represented by Boston City Councilor Charles Yancey, who said it's worth the investment, but, "I don’t believe that we should oversell the idea because it deals with incidents after the fact. The city’s focus must be on the prevention, the preemption of violence rather than arriving after the fact, which by it’s nature is what the ShotSpotter is all about.”

Again, Councilor Consalvo responds:

"Well, we do both, and I think it’s necessary that you do both. We pour hundreds of millions of dollars into prevention the piece and I am a strong supporter of that. But the sad reality is that no matter how much money your pour into prevention, you’re still going to have instances of gunfire in our city.”

The Boston Police Department has proposed expanding the technology to other areas of the city, but an effort to include the expansion in the city budget failed last summer.


It's taken some time to figure out the acoustical signature of the city. Sounds picked up by sensors are fed into a computer at police headquarters.

"They triangulate those sounds and then analyze to filter out things like backfires from cars, motorcycles, anything that can produce that can produce a loud sound," Daley said.

The department sites an incident last year where acoustical and video technology led police to a crime scene providing vivid detail on the gunfight and location of ballistic evidence.

"In some locations we've tied ShotSpotter in with video cameras, so that when the ShotSpotter detects a gunshot it directs a nearby camera to turn to those coordinates to collect information," Daley said.

While police say the system is not designed to pick up on private conversations, the American Civil Liberties Union of Massachusetts said it has some questions about the technology, but so far has taken no action.

The technology is being used in scores of other cities across the country, including in Springfield and New Bedford here in Massachusetts.

This program aired on December 23, 2011.

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Delores Handy Reporter
Delores Handy was formerly a host and reporter at WBUR.



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