Good idea, but needs to go further.

Train all teachers and staff (that want to participate) in a defensive firearm training program and provide them with a handgun of their choice. No one knows who these teachers/staff are except the training program administrator and the security guard. Refreshers yearly. Replace the "Gun Free Zone" signs with "Warning - Security guard, teachers and staff are armed and are trained to shoot to kill."

The perps are crazy, but they aren't stupid

The transcript...