Are these stealth drones?
I was led to believe that the police had a helicopter in the air - I'm a little puzzled how they are unable to follow the drone to its point of landing? Surely the drone has a much shorter possible flight time than a fuelled helicopter, and the heat from the ESC, motors and batteries can easily be seen/followed on FLIR camera, especially at night?
On a related note, despite the increase in "naughty pilots" (OK, imbeciles in this case), the airports and police still appear to have no strategy for dealing with this growing "problem" - like procuring and operating their own technology to aid in both the prevention of such issues and the locating and arresting of rogue operators? There are several possible approaches to this (ranging from capture nets, signal jammers; either for control or FPV, Blinding FPV cameras with lasers etc) that could form the basis of such a strategy. Is this simply an "acceptable risk vs cost" situation?