It's an inexpensive way to give teachers a chance to protect their flocks. It's not a weapon that requires training and it is not lethal. It's common sense.
It is also applicable in office settings. We've had as many workplace as school-related shootings.
Schools are different, though They are places of acceptance, learning, exploration and innocence. This makes them easy targets of those who act out their rage.
Just do the best your can, Claudia