The Dark Knight's Dark Night (Shooting in Aurora)

Oh, so we train everyone who get's a gun now, so people actually know what they are doing when they have a psychotic break down. That's a fine idea, because you know, a trained gunman would have been able to get a clean headshot at this guy before unloading 2 ak47's onto an open crowd. Ya know, by surprise.

Seriously, have you people handled a gun before?

Not trained as in marksmanship, but trained as in gun safety.

Also, the gunman didn't want to die, making him much less likely to open fire if he knew there was a good chance that someone (or several people) in the crowd were armed.