So you think this maniac stopped and thought, this is a gun free zone, no one will have a gun so I can shoot more people. Do you really think all the tough guys and girls carrying guns don't ever carry them into a gun free zone? I find it hard to believe in that entire Wal Mart, in Texas no one was armed.
Unless you are current or former military or a first responder, you have no idea how you would act when faced with this situation.
The NRA would just love everyone to carry a gun everywhere. That will never happen.