And I read she was a teacher’s aide. It seems the school’s website has been taken down so not sure if she was a teacher or not. So much we don’t know yet.
One of the early reports said that his mother had called in sick (or maybe he had called in for her, since by then he had probably already killed her). I guess that’s why they buzzed him into the building, because they knew him as her son and probably thought he was coming to tell them something about her or pick up something.