The guns aren't it, and neither is mental health. That said I wouldn't mind tighter background checks and more limits on semi autos, or not, I don't think that will change much either way. Nor do I think armed teachers is the answer; I'd bet a dollar to a hole in a doughnut it causes trouble before it saves anyone, we shall see.
The thing that's causing this is the one thing NOBODY wants to look at, nobody want to take this blame because this blame can only be placed when looking in the mirror!
Parents these days, its not lack of religion or faith, or any of that, though that stuff can be good or bad like anything, depending on it's apllication. I've seen agnostics and religious folks alike sucessfully raise great kids. The simple fact is though, most of us, well intentioned as we are, are either to caught up in making a living, the daily grind or whatever it is, and have too little idea of how even to relate to our kids much less parent. All too often parenting consists of paying not a ton of attention, till the kid gets in trouble, then getting emotionally bent, punishing too severely, maybe taking it bakc later, being inconsistent, maybe, whatever it is. Sometimes it's mild physical abuse (which does not work ultimately) maybe it's neglect.
See they barely teach balancing a check account, interest rates, all the basic crap a kid needs to learn to adult much less prosper in this society anymore. Boys are shunned from home ec, if even it's offered anymore, and parenting classes? You gotta be kidding me, but even if it's a good kid, not having sex or making kids, how bad could a parenting course in health be for them?
Then there's bullying, overworked, underpaid teachers not connecting. Don't get me wrong, I give this maybe 10% to teachers, 20% bullies and peers, but a good 70% of the blame is at home. Even the best intentioned parents stuggle, and kids come with no operators manual. It's time we get to acknowleging the real reason our kids get so isolated, frustrated, and feel so alone,. Most of these kids aren't sociopaths, or even necessarily bad seeds, but neglect these problems long enough and they fester, when just learning to involve ourselves, be aware what is going on with our kids, not over disciplining, and definitely not neglecting disciple (worse). No I do not suggest trying to be your kids best friend, but something between authority and friend seems about right. That extra effort to connect with opur kids, if anything can reduce these incidenst, that is the one thing that will work.