Two cents: American schools need to clean up their act when it comes to bullying. Some schools will outright do nothing about it, and when little johnny has a breakdown they wonder what caused it. Some schools like mine may even have teachers who'd tell children to grow up when they start crying because they can't take daily torment and abuse. Surely not the only cause for it, but I think it plays a role in some shootings. I also am a believer in the whole "guns being too easy to obtain" trend. I don't know what types of guns in specific these kids are using, but if I had to take a guess, I'd say at least a few school shooters probably get the guns they use from their parents which is a completely different animal in itself to attack, but some may also go more devious routes to get them so tighter restrictions won't do much. When there's a will, there's always a way. Especially when you have security measures such as the great ol TSA keeping dangerous shit from coming in and out.