How difficult is it to get a conviction in a case like this (historic sex abuse)?

[nandio]

I'm not sure if this is the right place for this thread but I was wondering if any of you on here had any experience of this kind of case. How do you prove individuals like this guilty? What sort of evidence could there possibly be? Is the victim's testimony enough?

www.bbc.co.uk/news/uk-england-suffolk-42894462

Things such as;
Victims account, detail and credibility, consistant recall.
Witnesses, disclosure witnesses- who was told and when, other witnesses- people who were aware that he was visiting the house, or parents, other youngsters they may have propositioned.
Suspect interview- sounds like they incriminated themselves here with nonsense such as they "boy sexually assaulted me in the shower"
Bad character evidence, previous allegations and convictions
Any disclosure to made to professionals

The level of detail in the interview would be incredibly important

Thanks @Missymoo, those are the sorts of things I was thinking. Any idea what sort of sentence might be imposed?

Your welcome Nandio. I couldn't say about sentencing because it can vary- but I'd like to think it would be substantial in this case.