A number of police departments across the nation are integrating gun shot audio detection systems into high crime neighborhoods. A gun shot detection system uses microphones to determine the existence and location of gunshots.

Julia Layton from the How Stuff Works website explains nicely how the audio sensors function:

“Some sensors are designed to detect the sonic boom of a bullet that travels faster than the speed of sound. Others use sensors that pick up the optical characteristics of a muzzle blast, the explosion that propels the bullet out of the gun barrel.”

The GSDS has a number of useful services. First, they alert police to gun crimes faster than the typical 911 call. Once a shot is fired within the reach of a sensor, police know the exact location of a gunshot and can quickly move to the correct street or home. Whereas with 911 calls, the individual phoning in doesn’t always know precisely where the shot was fired.

They can also help correct witness reports about how many shots were fired, and how much time elapsed between shots. Which is important because 2 seconds between shots can present a much different circumstance than 10 seconds.

Camden, NJ Chief Scott Thomson told this story about GSDS at a Washington DC police conference in January. “The other night, we had four individuals go outside, fire off 15 rounds, and then go back into an apartment complex. The gunshot detection system immediately alerted us that the situation occurred and gave us a precise location. We sent officers into the building and ended up getting one of our most wanted criminals with five handguns in an apartment complex.”

It’s just another addition to a growing artillery of audio forensic surveillance systems and new crime fighting technology.