I was discussing in another thread how incredible it was that the social services let Fritzl take care of the children regardless of him being convicted of one actual rape (as well as an attempted rape, and indecent exposure). According to an article in the Guardian, these kinds of records only stand for 15 years in Austria, before they are deleted. Thus the social workers didn't find any record of the incidents, despite supposedly searching for them.
Here's the article (which is long, but really quite interesting): http://tinyurl.com/5jj2x3
How does this work in the UK anyway?