Why are we just learning about this now? The SS has been criticized for not having a drone up and they said nothing in their defense.
My neighbor uses a drone to spot deer prior to shooting season. He then knows where they hang out on my land. It is also great for finding a deer that is a runner after the shot. Unless it is a heart or head shot they can run 2 or 3 hundred yards before falling down dead. The drone spots the deer easily. How in the hell did that secret service drone operator not spot a shooter on a flat white roof? I hope it was just massive incompetence. If not, we have a real problem.
The acting head of USSS was asked if they had drones in the air. He denied it.