Schools, governments, and people can do everything right 99.9% of the time and it only takes that .01% for the bad guy to get lucky. Like a teacher going to her car to get her cell phone and propping a door open. That was about the dumbest move I have ever seen by trained "professional". Next to waiting 40 minutes in a hallway.
kwg
Too fat to walk around the building to get back in.
