Law Enforcement Drones
Police use drones to collect evidence for cases of law being broken as it is able to reach places that is normally not accessible to law enforcement units. Not only that, drones are increasingly being used for search and rescue missions, particularly in flood disasters.
In a future scenario, drones will probably be armed for the purpose of apprehending criminals on the run as they can be armed with stunt guns to immobilize their victims. But one of the most useful feature of drones is that they can be used for surveillance work as they can be cheap to deploy.