As an ex psychotherapist, I would like to say that people with psychological problems dont way up problems like, which school has the best security, before they go on a killing spree, they dont operate like that. They want revenge or to unleash their anger over whatever they have become focused on as their reason, for justifying their intent. The film and computer gaming industry de sensitize the emotional aspects of killing and the hero is always justified in his actions, and never suffers consequences or sees the emotional impact of them at the end of the film. Depending of what psychosis a person is suffering from they may not even have that ability to to connect emotionally with another being. Trumps lack of empathy for anything other than his own personal experiences is typical of a narcissistic sociopath, he may not have a gun, but he has a button, and if he could, he would have pushed it already to take out North Korea's president with total disregard for anyone else who would die as collateral damage and feel justified for doing it just because he wants to. People who have mental illness dont think like the majority of people because they operate in a different reality, and the majority of people cant understand that, because they don't operate in that individuals reality. If you arm the teachers the psychotics will still do the same thing but maybe up the stakes and use a bigger weapon of destruction that they can get hold of.Why dont they blow the schools up with Semtex or a grenade launcher...because its expensive and illegal and you cant get them without a lot of paper work and hassle. They use the best that they can get for the money they have and the least amount of hassle it takes.