As I noted earlier, I’m a retired urban public high school teacher. Arming teachers as shown in the picture from post #5 would not work at all. Some kid would grab that gun before the lunch bell rang.
I’m not saying that kid would necessarily be a lunatic, bent on shooting up the school. No, it would be more like putting a can of beer on the hallway floor. Somebody would go for it, just because.
I can see armed teachers working in private schools. But not in schools like where I taught. The risk/reward calculation would not be favorable. That’s why I argue for giving teachers quick access to firearms instead.
Firearms safety class is mandatory.
If you do not want to bre killed with your own gun, the rule #1 to prevent it is that you keep your gun in your possession and under your control at ALL times. Never ever forget it.