Gun Shot Detectors

Schneier thinks these are a good idea. Personally I think they are a waste of money.

They hope a new tool will help get them to the scenes of shootings more quickly and with greater accuracy.

The tool is a gunfire detector gadget. Its wireless sensors pick up the sound of gunshots and differentiate from other loud noises, such as fireworks.

When a gun goes off, a sound wave registers on the device, which sends a message within seconds to the police dispatch computers. It can detect gunfire as close as 10 feet away in a two mile range.

Yeah, that and the gun shot was fired outside of a building. So if you're attacked in your home you're out of luck. From their own website:

ShotSpotter utilizes the principle of acoustic triangulation to locate gunfire across wide areas. Because of its patented spatial filter technology, ShotSpotter systems are not fooled by noises which sound like gunfire but are misleading (like car backfires, firecrackers, etc.). Similarly, the technology filters out echoes and other acoustical anomalies. Using a continuous feedback loop which constantly adjusts sensor trigger and other parameters, ShotSpotter is able to deliver instantaneous system reports to dispatchers within seconds of a weapon being fired.

So gun shots in a house are substantially muffled and altered, so this won't be of any effect.

Back to that article:

"We want to create the impression, if not the reality, that if you fire a gun in Minneapolis, you are going to get caught," Reinhardt said.

Yeah, nice propaganda, but completely false with regards to reality.

Schneier:

Recently, I was asked about this system on Winnipeg radio. Actually, I kind of like it. I like it because it's finely tuned to one particular problem: detecting gunfire. It doesn't record everything. It doesn't invade privacy. If there's no gunfire, it's silent. But if there is a gunshot, it figures out the location of the noise and automatically tells police.

I suppose it's a wonderful solution to outdoor crime like drive by shootings, but it's so limited in use for other issues that it's questionable as to whether the cost is justified.