Go back bit future and prevent the Columbine shooters. Done some studying on that day. Couple flat tires and a motail cocktail in the basement they hung out in before the shooting would have ended that.

That's dumb.

What would've really needed to happen is to speak to the parents and the school about "hey, your child and student is doing some pretty fucked up things and they're raising the stakes soon, so you may want to commit them somewhere or talk or smack some sense into them"