I'd wager that since the FAA considers drones as aircraft, even if you crash one inside a building they might investigate if damages suffice, much as they do for normal aircraft inside a hanger that hit each other, people who are struck by a spinning prop (I know one guy who got a metal plate on his skull for doing that trick!), or on ground collisions. Doesn't have to be in the air, just something to do with aircraft and some injury. I don't think the local aircraft mechanic calls the police should he forget to chock the wheels and accidentally starts it and flies into the shop wall.
Since the feds put the FAA in charge of these things, no doubt their involvement is greater, or will become greater, than we think. Local level is still pretty much still "Duh!" and they may call them anyway. Flying one inside a church that goes out of control and slices up a few people may be a FAA call under their reckless endangerment call or rule for flying over people inside or not.