If they want to train the teachers, then they need to have a student holiday and run some simunitions exercises. It would be great to include the teachers and administrators who won't carry just to show them how far away police help can be in the event that such attack occurred... And to show how well the "protective" measures that they have in place actually (don't) work at stopping a determined attacker.
^ this ^
Teachers aren't stupid, just uneducated.
.44 Special: For those who get it, no explanation is necessary. For those who don't, no explanation is possible.