He clearly reacted like a psychologically sick person.
The good news: the youth of today are more prepared than ever before in technical subjects (this piece of good news is just to soft up what is coming...)
The bad news: most young people today have had a very poor human relations education, and they're ill prepared to deal with the tough challenges facing them.
Expect more of this kind of tragedies in the future.
We are fuelling an incredibly dangerous fire. We don't give our children enough attention, but at the same time we teach them that "they're special". We inflate their egos since a young age. We bribe them. We can't beat them, we can't show them limits clearly. (not that I defend beating people up) We don't really know them. We don't understand them. We don't know who they are, because finding out is too hard. In many instances, like parents, we don't know who we are ourselves. How can we help someone else to know who they are?
And worst of all, when they go out on a killing spree, we make sure we publish it in all kinds of media, with all sorts of details. It doesn't take a rocket scientist to see that those frustrated paranoid teenagers that see all the "glory" and airtime that his man gets, may well choose to have a similar goodbye, knowing that after it all, they'll be famous...even for a few hours. They'll be somebody...someone will care for them.
Because that's what is really missing from their lives. Love, attention, understanding.
However, the killings in the future will be different in one crucial aspect: they'll be bigger. Expect to see more group killings, in which two or more of these people work together for bigger "glory". Expect to see explosives. Expect to see more meticulous and detailed operations documented before the killings.
It is natural: tough privatized high school system with high fees + absence of love from parents + continuous bombardment from the media with advertising that makes them feel ugly/fat/inadequate + video games + complex world + rising unemployment + easy access to weapons = paranoia, violence, suicide