[Cindy of Nashville]

If one person in that theater had a concealed carry permit and had their gun with them, the bad guy would not have been able to kill as many people.
Back 25 years ago when airplane hijackings were going on everywhere in the world, my dad had a remedy to stop them. He suggested that they issue a gun to everyone as they board the plane. There would be no more hijackings and no more hijackers.

[Tenacious 1]

If one person in that theater had a concealed carry permit and had their gun with them, the bad guy would not have been able to kill as many people.

I've given that some thought. In a crowded theater, as pandamonium erupted in the dark, with teargas spreading in the air, the tactical opportunity to get effective shots at the perp would not have been favorable unless there were several folks or at least one in a good position early in the event.

In short, I would have been sitting in the middle of the theater. By the time I realized what was going on, I expect bodies would have been going in all directions. I suspect that most of the folks that escaped unharmed didn't get a good look at the perp at all.