I realise this is a huge subject and possibly not in the correct section, but can anyone give me a little understanding?
I went to school with a man who still lives nearby. He has an older brother and a much younger sister. Parents married and still together (relevant?) Mum is a district nurse and dad does something white collar in the building trade. The older brother was very bright and went to Oxbridge, this man was averagely bright, always into computer and that's what he does for a living. The family always seemed "normal", quiet suburban family, kept themselves to themselves, but normal. (nothing here that hasn't been reported in the press)
He has just been found guilty of child abuse. It's come as such a shock. He lives very near me (and my DC) and both his siblings have little ones. He still lives with parents (aged 40+, the only not so "normal" thing about them?) so the GC will have been around him a lot 
Anyway, am I looking for an explanation where there will be none, or is it likely that he experienced something that lead to this?