I'm heart-broken for those families, who will ever after struggle for peace on Earth and good will towards men, I imagine.
I'm not saying they don't need help and support. I just think it's a little too easy to write off the killing of children by irresponsibility due to mental illness. If you ask me, those kids are just depressed and suicidal, and would rather go out in a blaze of glory, even if it means being labeled as monsters, than just off themselves and be unknown. We're not talking about somebody who wasn't fully aware of the atrocity of his acts here.