Don't know the specifics of what the OP is referencing, but some police departments are experimenting with some wild tech. Check out the Baltimore "Spy Plane", for instance. It used high-altitude Cessna airplanes (rather than drones) equipped with a massive array of cameras, that recorded everything.
It allowed analysts to:
- Watch and record a 30-square-mile area of the city simultaneously, in real-time.
- If a crime occurred, they could "go back in time" to see where a suspect came from. Ie. track a vehicle from its destination back to its source.
- Or they could follow a vehicle "forward" in time to see where it parked, identifying potential hideouts or residences.
Of course, it was recording everyone, not just criminals.