The university should have advised the young women to get a restraining order against the kid, that would have kept him from taking the same classes as the girls, kept him from getting the guns, and brought the law enforcement into the picture. The teacher told the kid that he couldn’t behave the way he was in her class and he told that he could. The police would have informed him that he couldn’t, at least not within five hundred feet of the girls who complained.
Good point although, I don't know the details of how to go about that.