In the days since the Sandy Hook shooting, several people have been suggesting we put guns in the hands of school staff, including teachers. I think this would only lead to more school shootings.
My daughter, a high school teacher, has told me some of the things that go on in the schools. At one time, she had a substitute teacher actually choke one of her students, and another substitute filling in for a colleague of hers left in the middle of the day crying due to the horribleness of the students. Even some of the teachers are at their wit's end. If these teachers had access to guns in these situations, there may have been shootings instead.
Teachers are under a lot of stress, being expected to reach unobtainable goals such as those in No Child Left Behind, and students often don't face any consequences for bad behavior. Students can be brazen and confrontational, and I could easily see one of them trying to take a gun from one of the teachers.
I have worked in schools for seven years and there are teachers I would not want to see have a gun. I just do not think that guns in schools is a good idea. Give teachers training in shooting situations. Help them avoid the conflict if possible. We should be focusing more on the mentally ill that are exhibiting violent tendencies and working on getting them help and making sure they are not in a position to obtain the weapon in the first place.