I'm a veteran urban high school teacher. A fellow teacher was repeatedly threatened by a violent student (a psycho white kid, by the way). So my colleague took to carrying a heavy 2-foot solid iron ring stand with him whenever he walled in the hallways. Since he was a science teacher, no one ever questioned him on that.
He never got attacked either.
I'm also a veteran high school teacher. I get threatened by urban high school students all the time. They gonna shoot me, stab me, end me, jump me, etc. My stock answer has always been, "You and whose army gonna do that?" Generally, it's all a bunch of hooey for the benefit of their fellow students in order to show off or gain street cred. My hands are usually too full of stuff to be carrying around a ring stand or anything like that. Let's see what this poor teacher's UNION does about this. Probably nothing, like most of them.