How about this: An armed citizen walks around the corner and sees a man holding a rifle a 30 yards away. The man fires, and down range it can be seen he hit an unarmed person. Armed citizen pulls out handgun and shoots terrorist 5 times.
The only way this will stop is for a armed good guy to be there when it happens, see it happen, and be close enough to return fire. The odds of this are much greater the more armed good guys are out there. The police are not enough.
Agreed. More guns, less nutcases.