Did you know that in Connecticut it is legal for teachers to be armed, if the school system permits it?
Do you think the principal at Sandy Hook would have used a pistol if one had been available?
If your contention is that teachers are there to teach, not act as police, consider this.
Teachers are not firefighters, but every one is trained to use any available fire fighting equipment, such as fire extinguishers.
Before you say that teachers SHOULD NOT be armed, go out and ask the teachers.
Ask them if they feel that throwing their bodies between their students and a madman is their first choice.
Find out how many of them are already capable and licensed to carry firearms, and are only prevented from doing so by current ideology