I think it's an incredible "luxury" that we know who and where this shooter is. Most folks involved in such situations are victims of the fog of war, which makes the situation far more difficult to deal with.

Normally, I think we'd have to deal with questions like: What's going on? Who's doing the shooting? I wonder if that's the police shooting? Where exactly is the shooting happening--I can't see anything? I don't hear any shooting--will I run into the shooter on my way to an exit?

Given the scenario outlined, and with a clear path to an exit, is there any sane option other than to immediately grab the family and sprint out of there back the way we came? No thinking, no analyzing the tactical situation, no counting rounds waiting for a reload, just ACT! Nothing short of rounds knicking the finely polished marble floor around my feet as I'm running away are going to steer me off my straight beeline for the exit.

Of course, I'm open to hearing other ideas and I don't mean to shut down further discussion by sounding so sure, but to me, the choice is pretty black and white given the facts presented.

Let's not underestimate the power of an overwhelming, loud, horrifying, life-and-death situation to paralyze you into freezing up and thereby opening yourself up to becoming fish-in-a-barrel shooting victim #8 for this guy. Except for folks with actual training in such situations who have some idea of how they react in such situations, I think your average civilian needs to mentally rehearse just getting out of Dodge when the hot lead starts whizzing around so that when the S hits the F, your mental rehearsing kicks in.

I think Sanford Strong and his book Strong on Defense is a good primer on how to deal with violent situations in daily life that doesn't really have anything to do with weapons or gadgets or techniques or heroics. It's just about surviving a violent situation, period.