Can I offer a different take? While not all school shootings, or "pre"shootings are the same, in a lot of them- Columbine being the most prominent- bullying is a factor. MSNBC mentioned that the boy was taken out of the school for being bullied. Eric Harris and Dillon Kliebold were bullied mercilessly as well. Now, being bullied does not justify murdering your fellow classmates, but in all honesty why does nobody ever investigate the bullies? You have to be bullied pretty damn bad to want to go back and shoot up your classmates. Moreover, why aren't the bullies, the ones who antagonized the kid, held to account? Not everyone in the world has the same capacities to deal with teasing. Moreover, teasing nowdays isn't like it was in the old days- it's no longer to get a simple rise- often, it's just to be horrifically mean just for the sake of hurting somebody else. We've reached the point where just telling a bully to "f- off" doesn't make them go away. A really bad bully can no longer be expelled. If the student reports a bully, they are accused of "snitching" and ostracized by their peers. If a kid is called, "weird" or "faggot" by their peers, the school counselor tells them to "embrace difference". I don't think all school shooters are "mentally ill" as the media labels them. Moreover, when a potential shooter, someone who is bullied mercilessly, sees a previous shooter labeled as mentally ill, what is he to think of himself? "Well, I'm teased, I think of hurting those who hurt me... oh God... I'm mentally ill... well, only one thing to do now I guess..." Nobody grabs the kid and say, "buddy, you're fine, the other kids are being jerks, it'll be ok..." Of course, one can't do that anyway, because it won't be ok, because nobody EVER deals with the bullies any more.
With the large increase in school shootings by students, one really needs to look at the situation... they can't ALL be mentally ill. I really believe that bullying plays a VERY large role in this. I think the reason behind the reluctance of parents to address this is that no parent wants to admit to themselves that their kid was the bully that antagonized the assailant to the point that he shot up his classmates. "Oh, my Jimmy is captain of the football team, he could never be..." wanna bet? "Oh, my Claire is on the yearbook committee, she could never..." uh-huh, girls can be worse than boys. Here's a notion... maybe some of the other parents should police their children. When growing up, I was told not to make fun of others. Granted, we all slip, but I was never party to outright mockery or slander. I think until the other-side of the coin is addressed, we will continue to see an increase in the number of shootings.
We had the same number, same type, and easier access to guns 30-50 years ago and nowhere NEAR the number of school shootings...