Keeping ear cocked for gunshots

A sophisticated acoustic gunshot detection system that has helped detectives in North Charleston, S.C., solve a homicide, and police in Gary, Ind., make 15 gun arrests in a single night may be on its way to Boston.

Councilor Robert Consalvo wants to equip the city with a network of acoustic sensors, each the size of a 1-pound can of coffee, which can pinpoint the sound of gunfire within 30 feet of its origin and dispatch police to shooting scenes in less than 10 seconds. Consalvo said he believes such a network can help police make arrests and stem Boston's wave of gun violence, particularly since much of it is concentrated in small ''red zones" that total about a half-square-mile.

''This will allow the police to respond in cases where people are afraid to call 911," Consalvo said. ''It also tells the criminals that are out there: 'We're watching you.'"

The Hyde Park councilor is talking to Mayor Thomas M. Menino's office about the technology, and Menino's spokesman said yesterday that the mayor will seriously consider it.

''We're at a time when we're being very aggressive about looking at proposals to minimize gun violence in our city," spokesman Seth Gitell said. ''Certainly we will take a look at this one."

Consalvo said he will also invite Police Commissioner Kathleen M. O'Toole and representatives of the company that makes the system to a public hearing in the next two weeks to discuss how it might help Boston.

It is the latest idea to respond to a surge in gun violence. Authorities are also sweeping through high-crime areas to seize guns, going after gun smugglers, planning to put monitoring bracelets on violent offenders, and talking about new bullet-tracking technology.

Last year, Boston hit a 10-year high of 75 homicides, 51 of them committed with a gun. Overall shootings increased by 28 percent last year, and by Feb. 16, they were up by 125 percent over the same period in 2005.

The gunshot detection technology relies on a network of acoustic sensors that its manufacturer says can track gunfire from as far as 1 1/2 miles away and can isolate shots from other sounds.

James G. Beldock, chairman and chief executive of ShotSpotter Inc., the manufacturer, said the system costs about $250,000 for the first 2 square miles of sensors. He said after the initial deployment, the cost drops to about $3,000 to $5,000 per sensor. For the system to work effectively, cities are required to install about 10 to 12 sensors per square mile, Beldock said.

Beldock said that one batch of 10 to 12 sensors would cover several of Boston's ''red zones" that are less than a mile apart. Many of the city's highest crime areas are clustered close together.

''I don't think we could break 2 square miles into 10 pieces, but we could certainly break it into a few pieces," Beldock said.

Consalvo said he recognizes that the system's cost may be a limitation, so he is also inviting Boston's homeland security chief Carlo Boccia to the hearing so that officials can explore the possibility of seeking federal grants.

Police Chief Garnett F. Watson Jr. of Gary, Ind., said federal grant money has helped his city pay for the system, which he says is so precise when recording where shots are coming from that officers have arrived at crime scenes and found suspects, gun in hand.

Watson and several other law enforcement officials in cities using the technology said police can deploy officers more effectively and efficiently when they're not relying on residents to report shots fired.

Watson said officers have begun leaving notes at houses telling suspects that the ShotSpotter system alerted police to gunfire. He said police have also had special units target houses where shots are fired routinely.

In Rochester, N.Y., a small city with a relatively large amount of gun violence, police are using federal money to install the system on both the east and west sides of town.

In Columbus, Ohio, Beldock said, the FBI hired ShotSpotter to cover 90 miles of Ohio highway with the system to help trap the highway sniper who struck there in late 2003 and early 2004.

Beldock said the FBI is currently installing the company's technology in Washington, D.C., to fight violent crime. And in North Charleston, S.C., police Sergeant Karen Cordray, who runs the crime analysis unit, said police credit ShotSpotter with a 31 percent reduction in violent crime last year in a high-crime neighborhood covered by the system.

Cordray said police there credit 21 arrests since 2003 solely to ShotSpotter. She said that in five instances, police have arrived at a crime scene and found the suspects still present.

''Our response time is two to three minutes to a shot spot call," Cordray said. ''ShotSpotter has already got the guy en route at the point when the citizen is calling. . . . It's never going to take the place of actual police work, but it's a great tool."

Suzanne Smalley can be reached at ssmalley@globe.com.