My thought on it?
That is the way it should have happened ! IDIOT raises a gun to kill or injure person or people, some one is around with a weapon that knows when and how to shoot, removes the IDIOT from the scene!!
I had this same conversation with two of my Teacher friends, one Female, one Male. The Male told me he kept a gun in his vehicle and so did the Principal and I'm not telling where he teaches! The Female said she would be for training those Teacers that wanted it and having a weapon/weapons available in the Office for Principals/Admin, Teachers in emergency situations. Now I live in Texas but I bet there are other Teachers out there that would get trained and or certified to be able to handle certain situation.