In Cincinnati, police used a system called Shotspotter to find and apprehend a 14-year-old boy who had a 40-caliber handgun.
Shotspotter is used by law enforcement offices and campus security offices to sense and record gunfire. The audio acoustics are recorded and time-stamped to triangulate the location and type of gunshots to within 10 feet. When the system makes a detection, it automatically notifies law enforcement and first responders.
Anyway, the juvenile was previously caught with a gun in January 2017 and was shot in the leg in the same Cincinnati neighborhood in September 2016. This time, the Shotspotter system recognized the same pattern of gunfire five times near a certain intersection since September 2017 (the intersection of Gilbert and Lincoln). After they made the determination that the gunfire was happening repeatedly in that area, some plain clothes detectives started doing surveillance work on that corner.
They located the juvenile and he was arrested for carrying a concealed weapon. Sounds like they got a problem kid off the streets.
Screenshot from video from wlwt.com