Why do criminals attack gun free zones? The answer is simple. They can not be shot back at. It is not often that a gunshop is robbed. More responsible gun carriers on a large school campus makes since. Columbine is a fairly big school, and the expectation of one armed guard protecting it all is ridiculous. No, schools do not know when they are going to be attacked. However, they can be more prepared with faculty and staff being armed and knowledgable about what to do if a threat ever occurred.