Can’t open the door by turning the knob after it has been locked by key.
But you make a point. If there is no where to hide and there is not bullet proof glass you could just stick your gun through a shot out door window and kill them.
For that matter, you could be outside, pop up, and kill them all through an outside window.
But the reason a lawsuit will prevail if allowed to continue is because they did not follow adequate security procedures by giving the teacher a key so that she could lock the door . That was the Standard Operating Procedure for a lock down and they didn’t give her what she needed to lock it down.
“Can’t open the door by turning the knob after it has been locked by key.”
This may not be true. That would be a fire marshall issue. How do the kids get out if there is a fire and the door was locked from outside.
And why does the door have to be locked from the outside and not inside?? Not quite understanding that yet.
You can't open the door from inside when it is locked??
That doesn't sound legal by firecode.
Where I live, and in many areas, a locked exterior residential door must be able to be opened from the inside by turning the knob and never require a key to get out from the inside. Deadbolts must be able to be opened from the inside without a key, that is, by twisting the lever. You can't even have one that needs a key and you just leave the key in the lock when you are home. Someone might borrow the key and not put it back. In a fire, you can't get out through the door.
You might say, well, there will never be a situation like that in a school. Then it happens the next day. More lawsuits.