Yes

If there was a mass shooter who was hiding in a building and h was not complying i feel that it should be necessary to have access to C4 explosives to be attached to a drone or RC to blow up the shooter. This strategy was used by our american counter parts. The Dallas Police Department was forced to use this method because the shooter was hunkered down and armed with a rifle. He had already Killed 5 police officers and injured 7.