There is no doubt that cities such as New York and Chicago have put together ever-increasing numbers of public and private cameras into giant surveillance networks. There are impressive successes and some concerns. For example, New York City officials recently stated that about half of the 4,313 security cameras installed along its subways are not operating. “A lot of those cameras do not work, and maybe someday we’re going to get very badly hurt because of it,” Mayor Michael Bloomberg observed.

Still, with all of the coverage that security video in public places gets, it’s easy to neglect some other “on-the-street” technology that supports public safety in towns and cities. One of these approaches is gunshot detection.

Law enforcement in some California and Indiana cities use gunshot detection — fixed and mobile sensors — that communicate with a police van equipped with the visual feedback data from the sensors and dispatch equipment serving as the mobile tactical command center. This command center also had the added benefit of tracking capability, so dispatchers could see not only the gunfire on screen, but also the position of all officers. Dispatch can easily tell those officers closest to the incident where to respond.

The City of Gary, Ind., and the Gary Police Department recently expanded a ShotSpotter Gunshot Location System. The system now covers an 8.5-mile area and includes the addition of a mobile software client, which will allow the technology to be used directly by both 9-1-1 dispatch and patrol officers.

Such systems detect, locate, alert and track gunfire and other explosive events in near real-time. Each event is logged into a historical database for strategic and tactical crime analysis that reveals crime trends, patterns and hot spots within a coverage area. Data also has been used to corroborate and refute eye-witness testimony, establish a timeline of events, and aid in crime scene reconstruction.