THATS WHERE THE PROBLEM STARTS!
Shouting for a reason. What you have stated, thats the problem. There is no responsibility, no self-responsibility. You've just removed it by asking who failed the boys. They failed. They failed society by their actions. They are old enough to know what they did was wrong.
Stop looking to shift the blame.
If these two kids were taken and publically shredded, and the footage placed on youtube, and well advertised that any doing the same would suffer the same fate. no one would do it again.
I am not suggesting brinign back hanging, but how about we bring back a little bit of responsibility, so the govt doesn't have to set a new law each week to tell us what we can and can't do. Let people make up their own minds on what they want to do, but utterly brutalise them if they go over the well predefined lines.
I would publically shred these two, I don't care what remorse they have shown, they could serve as a shining example of deterrant to everyone else in the country and it'll save the taxpayer half a million or more in jailtime and a similar amount to generate them new identities.