As morbid as it is to say, I wonder if this guy, Ostrem, just walked up behind people and shot them in the back of the head. That's kind of scary to think about. I've thought of how at times, we are vulnerable, even the most secured-minded people.
I think there was once some sort of incident in a Walmart where some troublemaker was taken down by a person carrying a weapon. Of course, all of this gets into "no gun zones" and all of that and this event will prove to be a headache for Walmart and other similar stores.