The tech listening for gunfire and fighting crime
14 July 2014 Last updated at 01:20 BST
There are thousands of illegal shootings across the USA each year - the majority being in metropolitan areas where it can be difficult for the police to respond quickly and accurately to the sound of gunfire.
But some cities now have a bit of help on their side in the form of gunshot detection technology.
Sumi Das has been looking at the sensors serving as law enforcement ears on the street.