So let me get this straight.. there was a shooting in the area, a teacher goes outside and "forgets" to lock the door again. The shooter having a $5000+ gun, 1500+ rounds while being piss poor makes his way to the school. He happens to find the one door that is left propped open by the teacher, enters the door and begins murdering people. At that point, the police arrive and stand there, refusing to go in and deal with the active shooter against their protocols. They stand there for well over an hour actively arresting parents who want to go in and save their children.
I am sorry, but man does that sound suspicious as hell. If I were a conspiracy theorist, I would say this was done on purpose