Acoustic Triangulation Reducing Gunfire in American Cities

By March 07, 2008

A Silicon Valley tech startup is helping police respond faster to illegal gunfire with a gunshot-detection system providing real-time accurate location.   ShotSpotter Inc., a Mountain View based company established 10 years ago,

developed technology that accurately locates gunfire through wired or wireless sensors (microphones) deployed throughout a city by geographically triangulating the sound. Police are given real-time information about the number of shots fired, the number of shooters, the direction of travel in moving gun battles, and a reliable location to respond. A police dispatcher receives an audible alert within 10-15 seconds of the gunshot and can send officers to respond. It’s faster than waiting for 911 calls that usually come in 2-3 minutes after a gun shot is fired.  Besides separating real from false alarms, the system also makes up for unreported gunfire. For example, 15 percent of gunshots go unreported in New Haven, Connecticut, meaning 85 percent of the time no one is reporting gunfire either out of fear or indifference. Since Boston installed ShotSpotter in 2007, police are now alerted to gunfire 80 percent of the time.   Still, police rely on 911 calls and ShotSpotter enhances their response to gunfire and verifies eyewitness accounts. Minneapolis Police Chief Tim Dolan, for instance, credits ShotSpotter with disproving an alibi of a suspect involved in gang-related gunfire.   Police respond faster, make more arrests, and discover more evidence to prosecute suspects. In turn, the rate of gunfire decreases. Shotspotter confirms they have reduced gunfire “by up to 75 percent in cities in which it has been deployed for the past decade”. Oakland, Calif. reported a nearly 50 percent drop in gunfire in the year after ShotSpotter was installed.    ShotSpotter technology has also provided reliable information to authorities in some high-profile cases.  In January 2008, the FBI revealed that ShotSpotter technology aided in the recovery of shell casings in the 2003 shootings near I-270 in Columbus, Ohio. Unable to find the location for the shooter, 90 miles of the Interstate were covered with sensors. Recovery of the shell casings tied several shootings to the rifle of the suspect.   According to their web site, “ShotSpotter has deployed more gunshot location systems, detected more gunfire, and saved more lives than products from any other company. Our systems are deployed in more than a dozen cities in the US, in addition to contracts with the US Army, the US Air Force and the US Joint Forces Command. With nearly a decade of experience deploying urban gunshot location systems, we have the experience with allows us to deliver consistently good results, excellent system uptime and unparalleled forensic assistance both to investigators and prosecutors.”    ShotSpotter is a recognized leader in its industry. Their partners include Bishop Rock Software, ThinkGeo, Digital Surveillance Solutions, and Enforsys, among others.   Find out more information about ShotSpotter technology on their website.   Kathleen Clark L’Atelier   FEEDBACK For comments on this article, email us at

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