So the point of this thread is that crimes are in fact much more the fault of society as a whole than the fault of the individuals committing those crimes?
As a consequence, we should put a lot more weight in preventing those crimes to happen, by making sure everyone "fits" into society (or at least doesn't feel rejected), rather than concentrating on the repressive part, i.e. punishing the criminals and locking them up where applicable?
I'd say that's not exactly a new idea, but it still has a lot of value. The only problem with it is a rather practical one: how do you implement it?
Education goes a long way, but is certainly not the ultimate solution. Oh the irony, those killings went on at education sites...
So, reeducating the whole society to make sure there's no bullying any more (impossible, I believe)? Assigning a big brother per citizen to follow your mental development (no thanks)? Training teachers, coaches etc to detect "abnormal behaviour" (difficult, VERY expensive, and possibly ineffective: difficult kids tend not to show their feelings to teachers, and teachers already have a lot of work)?
The best solution is probably just good old fashioned parenting. I believe parents expect too much from teachers and school in general. A socially failing kid is often a sign that parents failed at their task. But in a world where both parents need to work all day...