The tech listening for gunfire and fighting crime
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.
UK gun crime: Should police retry gun sensor technology?
Watch more clips on the Click website. If you are in the UK you can watch the whole programme on BBC iPlayer.