and you're one of them...a suicidal shooter starts firing somewhere behind you or to your side...you turn to the sounds...all of a sudden multiple people join in with their own firearms...who is the bad guy you are going to aim at?...you have no idea, but you're carrying your gun for just such an occasion and you've just got to be one of the heroes...admit it...there's going to be chaos.
Better that major Malls hire more trained security officers (hey, you can sign up)...and let them handle the situation...or have metal detectors in all big malls with armed and trained officers nearby. Have everyone else keep their guns at home...period.
The 'Vector' we need to follow is one that eliminates Assault Rifles and sharply reduces the number of guns in circulation...just like all the other countries of this planet that have far fewer gun homicides than we do...thanks to their restrictive gun laws...we've got all the 'Militias' we need already.