Israel used to have an issue with Palestine's running in and shooting up schools, they armed their teachers and wala, no more douches attacking schools. In this one event, it may have not done anything due to the perpetrator was in fact the teachers son. Even if teachers suck at shooting the fact of a school being armed will be enough to scare people away from this type of thing. Ever heard of a mass shooting at a gun show in Texas? I would not leave it in the desk as that is the actual drive against anti gun nuts. Kids could get to the gun if they try. If the school goes into lock down all the teacher has to do is put the kids at the corner and aim at the door way. The worse thing about this shooting is that there were little no survivors, this means they were all head shots which leads to a video gaming history. I'm not discriminating against video gamers, hell even I play battlefield 3.