They arrested him and yet never checked his house?
THAT failure is the police's.
The villain’s name is Marc Dutroux, and searching for either him or “Belgian pedophile protests”.
He truly is a murderous monster that almost brought down the government and the opposition and the judiciary and the police at the same time.
(note: even the wiki is painfully graphic)
https://en.wikipedia.org/wiki/Marc_Dutroux