As one of the millions of teachers in America I know there is one thing I don't ever want to be...a fish in a barrel.
Think of the hero teachers who've thrown their bodies in front of students taking bullets fired by mentally deranged mass murderers. If these heroes had had a weapon does anyone doubt they would've used it to protect those students? Aspiring mass murders who seek out gun free zones to commit their atrocities are inherent cowards. And they're also untrained and unprepared for anyone with the ability to stand up to them. As soon as someone with a gun shows up they either kill themselves or die.