Ok.
So, there are more points of armed individuals, than say a school.
SpatiallyAware wants teachers armed. Or, some sort of amred individual(s) on schools. Point being, that even with folks like that,.. you still can't prevent a crazy person from going around killing people.
You are right... You can't prevent crazy. What you can do it give people a chance - *Legally* to defend themselves or change the outcome from 8 stabbed to 1 or 2. That is what gun grabbers won't admit will happen.
http://www.freep.com/article/20140325/NEWS04/303250094/Syringe-Roseville-Home-Depot-gun
We have no way of knowing who the next person is to snap and cause carnage. We just don't. Our system of mental health and healthcare in general is so fragmented and locked down tight with privacy concerns that even when there are signs of instability the system fails to catch that individual before it is too late.
Gun grabbers want to take every means of defense away from law abiding citizens which further enables those bent on destruction to exercise their demons. I'd rather have a choice in the matter if I am ever confronted with it. Just my opinion but also my right - as defined by our laws at least today.
