Has any media outlet posted the surveillance video that purportedly showed the perp entering the school? I want to know how he entered the building in the first place. I'm going to make a SWAG that the doors were open and that he just walked in -- which should be the very first thing anybody who wants to stop "these kinds of events" from happening should focus on. Too many administrators, boards of education, and architects pay lip service to school security but don't really want to do anything serious about putting it in place and making it work.
Yes, I have real-life, first hand experience dealing with the insanity of those folks.