Well, you see, there were some incidents with some folks that were mentally unstable that were able to access firearms. So, society created "gun free zones." These "gun free zones" keep everyone that is logical, sane and law abiding from possessing firearms where they are prohibited. (*waves at Canada*)
I'm not sure where the answer really is. Even Chicago's Safe Passage program is failing. We certainly can't go all 'Better off Ted" and assign a cop to follow around every child.
Not to mention the whole, "who really trusts the police" issue that has been beaten to death by the media this summer.
Perhaps its not weapons that are the issue at all. Maybe its a social problem, where parents aren't doing their job. Maybe, just maybe if folks were held responsible for this type of activity we would see less of this.