Won't matter. My school has cameras in all hallways and the exterior. With nice high def color pictures.
We've showed video to parents showing their kid destroying school property, right on video clear as day. The response was "you're wrong. That's not my kid, my kid wouldn't do that."
You are arguing with someone that believes the problem of gun violence won't be fixed if there are no guns.
Stop trying to argue, reason doesn't work with someone that thinks this way.
If that's true that is completely against accepted procedure. Years ago they eliminated code words, signs slid under the door or anything else that can give away a hiding position.
The procedure in our school is that you stay hidden in lockdown behind a locked door and do nothing to let on where you are. You ignore PA announcements to come out, even from a trusted voice or the principal since they could be under threat of death.
You aren't cleared to exit lockdown until someone comes with the keys and personally releases your room.