With more than 80,000 AI-powered cameras across the U.S., Flock Safety has become one of cops’ go-to surveillance tools and a $7.5 billion business. Now CEO Garrett Langley has both police tech giant Axon and Chinese drone maker DJI in his sights on the way to his noble (if Sisyphean) goal: Preventing all crime in the U.S. In a windowless room inside Atlanta’s Dunwoody police department, Lieutenant Tim Fecht hits a button and an insectile DJI drone rises silently from the station rooftop. It alr...