It sounds like something out of Minority Report, but the Los Angeles Police Department (LAPD) have already deployed a spy drone to monitor Compton, a small city with a higher-than-average crime rate. The single drone, the size of a Cessna aircraft, would fly high above the city, utilizing aggregated data from crime reports to predict where it would likely catch a crime in progress. The craziest part of the whole experiment: it actually worked.
As the drone circled the skies above Compton, a report came in of a woman's necklace having been ripped from her neck. Checking the video from the drone, the cops were actually able to not only see the crime take place, they were able to identify a getaway car as well. Depending on your viewpoint, the downside of the program (as the cops see it) was that the drone's camera was only good enough to watch the crime happen, not to identify the criminal or the car's plate number.
The LAPD meant to rely on traffic cameras and the like to identify the criminals, but the car made it out of their drone's surveillance radius before they could get a good look. If they had gotten a good look, the cops would have used facial recognition technology to gather a 50-person list of possible suspects. These images are gathered from not only mug shots, but just about any contact you might have with a police officer. That means that if you are pulled over for speeding, you could end up as a suspect for aggravated assault if you look like the person who did it.
The worry is that, contrary to how policing has worked up until now, people will now have to prove their innocence rather than being assumed innocent until proven guilty. Fingerprints, retina scans, palm prints and facial recognition data could all be used to pare down the suspects. But if you're incorrectly identified with these tools it might appear to a jury that you're guilty simply by the weight of evidence against you.
As for the drone program, its temporarily been put on hiatus, but the LAPD states that if the drones cameras are improved they'd be happy to get it in the air once more. Skip to the 8:30 mark in the video below to get a better look at the drone as it looked when last deployed.