Mr Z was an elementary school French teacher I had for a year. Like many French teachers in peripheral Anglo-Canadian communities, he'd probably spent decades trying to teach French to kids who mocked him without mercy for his efforts. When I got him he was old, very angry, and verbally and physically abusive. Chalk-brushes, text-books, and sometimes chairs and desks impacted the bodies and heads of 10 year old children when he'd go apoplectic. Of course, this being a Catholic school, abuse of this and darker natures was ignored or covered-up.
I hate to think what might have happened if Mr Z had been armed during one of his fits.
The assumption that for the purposes of firearms possession and use teachers are universally saintly creatures, is beyond me.