Notes on the Orlando mass murderer
1. He was a licensed security guard, working for a firm that provides security for nuclear facilities. So he passed (we may hope) some very tight background checks, and had a status that would have exempted him from most gun laws. (Even in DC, licensed security guards can carry. The peasants are to be trusted when they protect the nobleman's property).
2. He attacked (as seems to always be the case) in a gun-free zone. Must not have read the law. And this being Florida, home of "shall issue" concealed carry permits, gun free zones are about the only place where mass murder is feasible.