People don't stop killers. People with guns do.

Excerpt from an article linked here:

Virginia Tech doesn't have that kind of trust in its students (or its faculty, for that matter). Neither does the University of Tennessee. Both think that by making their campuses "gun-free," they'll make people safer, when in fact they're only disarming the people who follow rules, law-abiding people who are no danger at all.

This merely ensures that the murderers have a free hand. If there were more responsible, armed people on campuses, mass murder would be harder.

In fact, some mass shootings have been stopped by armed citizens. Though press accounts downplayed it, the 2002 shooting at Appalachian Law School was stopped when a student retrieved a gun from his car and confronted the shooter. Likewise, Pearl, Miss., school shooter Luke Woodham was stopped when the school's vice principal took a .45 fromhis truck and ran to the scene. In February's Utah mall shooting, it was an off-duty police officer who happened to be on the scene and carrying a gun.

Police can't be everywhere, and as incidents from Columbine to Virginia Tech demonstrate, by the time they show up at a mass shooting, it's usually too late. On the other hand, one group of people is, by definition, always on the scene: the victims. Only if they're armed, they may wind up not being victims at all.

"Gun-free zones" are premised on a fantasy: That murderers will follow rules, and that people like my student, or Bradford Wiles, are a greater danger to those around them than crazed killers like Cho Seung-hui. That's an insult. Sometimes, it's a deadly one.