Shotspotter CEO Answers Questions on Gunshot Detectors in Cities

Note that that's extra tricky, because there are two generally sounds: the first received will be from the shock wave of supersonic bullet, then the report from the rifle.

Not every gunshot has a victim (or is intended to).

[Edit: I misunderstood]

Ah, I might have mistook your surprise for an assumption in the other direction. I agree, I do not think that crime levels justify this sort of expenditure or monitoring. Maybe part of the appeal for law enforcement here is something that emergency hotlines can't replicate: this sort of system allows the police to be virtually omnipresent. An emergency hotline requires an engaged citizenry, one that would call the cops when a shooting happens, something that many pundits would argue crime-ridden communities are lacking.

Witnesses calling the police can't reliably locate the source of the gunfire. Wind, hills and buildings carry, echo and deflect the source beyond any hope. That's why a triangulating system like this is essential.

I don't doubt that you can hear gunshots in the rough parts of Oakland or LA, but this idea that people in the US are constantly in fear of getting shot is just so ridiculous.

I happened to start working with a similar system today. For our customer there are several factors they are interested in:

# Mapping gunshots in both time and space. These types of sensors can attempt to classify the type of weapon used based on the audio signature. If there are are several shots from similar-sounding sources moving through the city at a certain, or in a certain area over the period of days (or month), this can tell you more than you could determine from just emergency calls.

# Tieing the gunshot sensors in with other input devices, like cameras. You can reduce the time spent looking through, say, traffic camera recordings that happened in the vicinity of the gunshot looking for related video.

# Automatically pointing moveable cameras to look in the direction of a gunshot. Means you don't need as many camera for the same effective coverage.

Depends where you live. We've had gunshots in our neighborhood every day (or very nearly so) for 2+ weeks. I lost count of fatalities sometime around 9. Bit of a gang war going on here.

The ShotSpotter they put in last fall is definitely seeing some use here.

Gun violence is made up.

> That, in fact, is what sparked the American Revolution, when the British attempted to seize or destroy gunpowder, cannon, etc. (they did manage to damage 3 cannon).

This is a pretty absurd over-simplification of the causes of the American Revolution. Lexington and Concord certainly involved a British march on militia supplies including weapons/ammunition, but those weapons/ammunition were being gathered not for their own sake, but because of decades of tension over taxation, quartering, limitations on public gatherings, things like the Boston Massacre, etc. leading up to war. The Massachusetts militia weren't just a bunch of gun collectors who got pissed about gun control.

> it is my impression, such bad areas are much more compressed

I'm not sure ghettoization should be pointed to as a success story.

Even when the homicide rate by guns is 10 times higher than the next developed country, you still don't see a problem.

That's also not the relevant number. In places like Chicago, what you end up with is a tiny proportion of the population (say 2000) that is perhaps 100 times more likely to be murdered and is a major drain on your city's image. This is fuelled by revenge killings; someone gets shot or shot at, their family/friends round up the posse.

So what you want to do is get people off the street before they start shooting, or if that fails, you get them off the street as soon as they start shooting in order to break the cycle.

At the moment, with the dispatching of officers etc, you find that it takes about 2 minutes from receiving a call to an officer being dispatched (that's from the London Ambulance Service). A lot of this is just the time between the call arriving and the operator working out where the person is. Before the call, there are perhaps 15 seconds where the bystander who calls up is getting their phone out and dialing.

In this case, with the new system you can in principle have two squad cars each half a mile away knowing where the gunshot is to a reasonable level of accuracy, perhaps within a couple of seconds of the shot itself.

Within a minute of the first shot, the police can be on the scene. In this case, the suspects have only just jumped into their cars, and so are picked up easily.

There's no opportunity for any kind of revenge, because the suspects are in a cell.

Of course it's not a fantastic idea for every city; but if you're a company that focuses on military hardware, filtering off into LA, Chicago and NY can easily be an advantage for all.

To my thoroughly trained ears they sound very different.

Thinking about it, to avoid false positives, companies doing this need to filter out fireworks, the proverbial car backfire (do they do that any more???), etc.