[Skybird]

You can be a symptom of a social community or culture, nevertheless still be responsible for your deeds, since you are no totally instinct-driven lower animal, but a creature capable of self-reflection and realising the difference between suffering and not-suffering in oneself, and in others (there is this thing like sociopathy which means a person being really unable to see that difference, what often even is to be noted in certain brain areas not being normally functional). Events like school shootings are a symptom for media culture, society's state, and disfunctional families (which often are a symptom themselves, for the state of the greater social community they are embedded in). Nevertheless, the shooters are still responsible. In a way they are victim and perpetrator at the same time. You really should hold them responsible by the terms of the law.

What you should not do is: learning from them, by hating them. Determination in stopping, countering them, and force them to accept the legal responsebility for what they have done, is enough.