Myra Hindley has been dead a decade. Ian Brady, 74, has campaigned for even longer to have the feeding tube removed so he too can die. But the failure to find Keith Bennett, the boy with the cheeky grin forever remembered from his photograph, has ensured the story of their murderous campaign remains alive.
Brady and Hindley, who died in jail in 2002, tortured five young people, killed them and buried them on Saddleworth Moor above Manchester. While the remains of four of the victims have been found, Keith Bennett's never were.
The first victim, Pauline Reade, 16, disappeared on 12 July 1963, and John Kilbride, 12, was snatched in November the same year. Keith Bennett was the third child to be taken, on 16 June 1964. Lesley Ann Downey, 10, was lured away from a funfair on Boxing Day 1964, and Edward Evans, 17, was killed in October 1965.
Twenty years after their convictions for the murders, Brady and Hindley were taken to the moors to help the search. One year later, the remains of Pauline were found.
David Kirwan, a solicitor who used to represent Winnie Johnson, Keith Bennett's mother, and had a series of face-to-face meetings with Brady at Ashworth Hospital in 2007, said: "I believe Ian Brady knows the exact whereabouts of Keith Bennett's grave and is capable of directing police to it.
"However, it is important to remember who we are dealing with and how he seems to enjoy bizarre mind games and manipulation.
"During interviews, Brady told me mischievously how, when he was on the moors with the police in 1986, he walked them across the graves of his victims. We are dealing with a highly unusual and unpredictable person."
Police believed that photographs taken by Brady of Hindley at the crime scenes were key to finding Keith Bennett's body. A remote area known as Shiny Brook, stretching up to five square miles, was identified from the photographs and was notable because it was up to a mile away from the burial sites of the other bodies.
Any attempt to find the body would be done without Brady's assistance. He refused to co-operate with police when they launched a covert operation to find the body nine years ago.
When he saw officers arrive on the ward, he waved them away without uttering a word.