A Weapon Against Crime

Tracking the sound of gunfire

The situation was dire. A sniper was terrorizing the area around Columbus, Ohio, firing randomly at drivers and buildings near I-270 beginning in November 2003. One person had been killed, others had been wounded, and more casualties were expected unless they could find the culprit. But weeks into the joint investigation, the Franklin County Sheriff’s Department and the FBI still had no solid leads.

Finally, during a strategy session with our law enforcement partners, FBI Supervisory Special Agent Ron Chavarro offered a possible solution—a private sector technology called ShotSpotter that he’d overheard others talking about at a conference.

ShotSpotter, he explained, is a new crime-fighting tool that helps locate and track gunfire using “acoustic triangulation”—caused when sound waves are recorded at two or more locations.

Employing a network of hidden microphones linked to a central computer, the system is designed to detect a shot within seconds. It can “hear” a gunshot, provide accurate location information within several miles depending on the number of sensors deployed, and archive the audio for forensic analysis. The technology is also capable of determining information relating to the direction and speed of shooters on the move.

But would it work in this case? Although initially skeptical, the task force leadership decided to deploy the system along I-270. Within hours of becoming operational, ShotSpotter began to register the sound of gunfire. The resulting data led investigators to pinpoint the location of the shots, where shell casings were recovered. Armed with this information, we were later able to locate and arrest the shooter—Charles McCoy, Jr.—in March 2004. McCoy later pled guilty to the shootings.

Impressed by the technology and its potential value in other shooting investigations, Chavarro brought ShotSpotter to the attention of our Washington Field Office Criminal Division. Working closely with the company, our Washington office devised a plan to offer it as a pilot program in the D.C. area to help agents and local police in more violent neighborhoods.

A partnership was set up between the FBI and the Washington Metropolitan Police Department in late 2005. Since then, the system has helped locate gunshots fired in urban environments and has guided authorities there to several homicides. In addition, because it differentiates between and filters out other sounds frequently heard in noisy cities, like car backfires or fireworks, it has cut down on police having to investigate unnecessary false alarms.

Soon the word began to spread to other FBI offices. Currently, the system is deployed in a dozen cities nationwide where shooting incidents occur more frequently. Special agents working these cases hope that by integrating technologies like ShotSpotter they will be better able to locate violent criminals and produce valuable forensic data in court to help convict them.

“This technology has been an invaluable tool in helping us fight violent crime,” says Chavarro. “We’d welcome the opportunity to partner with other law enforcement agencies in deploying and utilizing this system in other jurisdictions.”