Police and prosecutors are in new talks about the prime suspect in the 1978 murder of schoolgirl Genette Tate.
Devon and Cornwall Police have long suspected serial child killer Robert Black of murdering 13-year-old Genette, who was last seen in a rural lane in Aylesbeare, Devon, in 1978 but whose body has never been found.
There is now new hope of a prosecution in the case after Black last year lost an appeal against his latest conviction for the murder of nine-year-old Jennifer Cardy.
He had argued that his trial was prejudiced because details about three other child murders he had already been jailed for were revealed to the jury.
Police said they are now liaising with the Complex Case Unit of the Crown Prosecution Service to see if the appeal court ruling has "any bearing on the Genette Tate case".
It could pave the way for police to launch a case against Black based on his previous convictions.
Devon and Cornwall Police said they were "liaising with the Complex Case Unit of the Crown Prosecution Service to ascertain if the 2013 Court of Appeal judgement following the murder of Jennifer Cardy in Northern Ireland [in which Black's conviction and the use of bad character evidence was upheld], has any bearing on the Genette Tate case".
The force added: "This liaison is still at a very early stage and will take some time to complete."
Black was found guilty in 1994 of the three child murders in the 1980s - those of 11-year-old Susan Maxwell, from the Borders, five-year-old Caroline Hogg, from Edinburgh, and Sarah Harper, 10, from Morley, near Leeds.
His reign of terror finally ended in 1990 when he was caught red-handed with a six-year-girl hooded, bound, gagged and stuffed in a sleeping bag in the back of his van in the village of Stow. He had sexually assaulted her moments earlier.
But in 2012 he was prosecuted for a fourth murder, that of Jennifer, who was snatched as she cycled to a friend's house in Ballinderry, County Antrim, Northern Ireland, in 1981.
The paedophile is serving a total of 12 life sentences for murder and kidnap.