There's people I've seen already on facebook saying "If the people in the crowd were allowed handguns in the concert, this wouldn't have been ended before it started..."
1. The shooter was 32 floors up on the other side of the road, look at facts before spruiking the your preset answers.
2. Pull a gun out in a crowd with shooting going on, others are going to look around after hearing shots, see you holding a pistol and think they need to take YOU down on hero reflex... 3rd guy is going to see 2nd guy murdering you and shoot him on hero reflex, chain reaction.
The whole country is stuffed, if this was the Sims I'd delete the save file labeled 'America' and just start from scratch with the Goth Family.