Why weren't all the doors to the classrooms locked? They kept the police out, but not the shooter.
There was an end-of-year awards ceremony that morning, many attending parents picked up their kids afterwards. We know that one teacher left his room open so parents and kids could pick up backpacks etc before they left. We also get that the classrooms the shooter occupied were connected. Maybe one of them was that room.
We also hear now that the infamous outside door was one used commonly by parents picking up/dropping off kids. On that day maybe it was left unlocked.
Time should tell.
