We have trouble appreciating causal effects that are subtle, indirect, and cumulative over long periods of time. Today we have a lot of children infected with violence, but it's not a virus, it's a learned behavior. Someone taught the kids in the Trenchcoat Mafia to admire Hitler and how to make pipebombs rather than to tolerate differences and respect others. Finally, the means to carry out these violent plans is the ready availability of firearms. Without access to guns, none of these school tragedies could have taken place.
Guns are a critical risk factor.
There was no increase in juveniles stabbing or beating one another to death. Guns are not the cause of the violence, but they provide the means. A comprehensive policy to reduce youth violence and prevent more school shootings should address the motives, methods, and means I have just described. First, address the motives for violence through education and training for students and their parents. Conduct at least 1 hour of instruction each month on conflict resolution and understanding of violence.