there is also a system in place called "shot spotter" that helps triangulate gun shots to a specific location
I dont live in the worst part of the city but on ocassion we get to hear gunshots. Sometimes at night I'll listen to the police scanner and they receive the info before the someone calls it in and it is usually accurate within a stones throw.
it is quite amazing but at the same time the amount of surveillance that doesnt do shit to curb any violence is annoying.
There are cameras littered across the city, shot spotters, and Im sure a host of other shit we dont know about