General Discussion

Not liking guns and having horrible thoughts about the things that COULD HAVE but DID NOT happen, as this person apparently was reasonably well trained and handled the situation well, is not an excuse to find ways to charge the person who killed the mass shooter.

The guy brought a gun in where guns are not allowed by the mall's rules, but even that is not a violation of any state law. So fine, the mall can ban him. Regardless, he did a good deed, and likely saved a number of people, and he did it well. You say "thank you" to him. You also can say "thank you, but you violated the same rule as the murderer you shot, so under our rules we don't want you back here again," if it's more important to you to enforce the mall rule than it is to appreciate the outcome.

Looking for ways to charge this guy is just as much an abuse of prosecutorial power as it would be to try to prosecute a bunch of BLM protestors for littering because the cops started firing tear gas and some of them dropped signs as they went down and tried to flee. It's fundamentally unjust.

What if this person had been unarmed, and instead had cracked the shooter over the head with a chair? Smashed him with a newly purchased baseball bat that a customer had dropped? Same dead shooter, same hero who kept more people from being killed or injured. I'm sure the mall's rules also forbid fighting, which that would have been. Still want the guy to get prosecuted for anything and everything if he'd used a chair instead? It's absolutely foolish to make the distinction.

A cop would not have been prosecuted for shooting the shooter, whether for "endangerment" or "manslaughter" or any other such nonsense. The guy who intervened may have had as much, or even more, training and know-how than a cop. Either way, he took care of it well, possibly as well or better than a cop. Once again, the ONLY way you prosecute this guy is if you just hate guns so much that you want to throw common sense and justice to the four winds, so that you can make an example of him just for having a gun.