True, you didn't actually say it but I got the impression that's what you thought from your posts.
I think that in order to do something that evil you've got to have something majorly wrong in your head somewhere & I just don't buy into the whole "It's their upbringing's fault" crap. Lots of people have messed up childhoods & as sad as that is, most don't kidnap & then torture a young child over a prolonged amount of time before trying to make his death look like an accident. Those are the actions of complete & utter [Poor language removed] sickos & no matter how bad somebody's upbringing is, it doesn't excuse them.
I see what you're saying about everyone being capable of being a killer, we all react to each situation differently but this wasn't just a "Moment of madness" reaction type thing, this was something they'd planned to do (as I think someone else has mentioned, they'd tried to abduct another kid before they got James) & even when they were going through with the vile crimes, not once did it click in their twisted minds that what they were doing was wrong.
I have sympathy for anyone who has a tough childhood, I really do but to just blame a set of crimes of this magnitude on it & say they should be forgiven is wrong. It's an insult to everyone else who's also had a tough childhood & has gone on to create a successful life for themselves & most of all an insult to the family of James & all who knew him. "Your son was tortured & killed but it's ok because the people responsible had a tough upbringing so you'd have probably done the same thing in the circumstances"