[Casseres]

Yes, designed to expand in order to stop, not designed to expand in order to harm.

I do feel for the teacher; the situation is not ideal and I wouldn't want to have to shoot someone I'm supposed to take care of either.

I think it's good that this teacher sounds like someone who doesn't want to use his gun (not "trigger-happy"), I just hope in the unlikely situation where he would have to use it, that quality doesn't prevent him from stopping a threat before more harm is done.