Fred and Rose West were a married couple who killed at least ten young British girls, some of them their own daughters. February 24, 1994 was the beginning of the end -- the end of the extraordinary things that had been going on in the ordinary three-story house in central Gloucester. But it was also the beginning of a discovery as the layers of secrets hidden at 25 Cromwell Street were slowly peeled away. Twenty years on, Sky News investigates the unanswered questions with an in depth documentary..