I mean for obvious reasons there is no scientific study here, but I get the feeling WAY more deaths would result from these guns being stolen and used in anger by students, by teachers being mistaken in the heat of the moment and being shot, by teachers who lose their cool in the heat of being bullied etc, than would ever possibly be saved by those guns. We know more people die of gun accidents in homes than are ever saved by them, so why would a classroom situation be different?