The conviction of James Hanratty still excites huge interest, and not just because of morbid fascination with how a married man was shot in cold blood at a spot called Deadman's Hill and his young lover left crippled.
For if, as many believe, Hanratty was wrongly convicted, there can be no belated Birmingham Six-style release for him: the small-time burglar was executed just two months after his trial in 1962.
The latest instalment in the Hanratty saga, which has been kept alive by his family and campaigners, is a potentially explosive Scotland Yard re-examination of the facts by Chief Superintendent Roger Matthews. His report is now with the Home Secretary, Michael Howard, awaiting a decision.
Although no details have been revealed, Ch Supt Matthews has intimated to people close to the case that his verdict is that Hanratty was wrongly convicted. His report is also likely to shatter the belief that just one person was involved in the killing.
Such a conclusion would almost certainly persuade Mr Howard to refer the case back to the Court of Appeal, where the conviction would be quashed. Even if he refused to refer the case, there would still be a legal hearing, because Hanratty's family say they would seek a judicial review against such an "unreasonable" act.
However, the posthumous clearing of Hanratty would not just build another plank in the argument against capital punishment, but would also raise the inevitable question: if Hanratty did not commit the murder, who did?
For many campaigners, including veteran investigator Paul Foot, the finger has long pointed at Peter Alphon, the man originally arrested for the August 1961 murder but later released.
Alphon made an alleged "confession" in Paris several years later. Foot, and others, maintain that he has - despite playing verbal games - stuck to this.
However, the former door-to-door salesman, now 66 and in poor health, claims that such people have "got the wrong end of the stick" and he wants a full inquiry into all the facts.
He told the Independent on Sunday: "I'm refusing to say whether I committed the murder or not. I do deny that I regularly confessed to it. I want a full public inquiry - I have nothing to fear."
His intention appears to be to encourage the authorities to examine all the background to the case, which is one reason why he does not want Hanratty to be granted a pardon. "I do not want everything that has transpired since to be brushed under the carpet. I want all the facts to come out," he said.
This is a clear reference to one of the most puzzling and important aspects of the A6 murder. How did the killer happen to be in the cornfield where the lovers regularly met?
The Scotland Yard report, which has taken 18 months to complete, is expected to address this point.
The apparent acceptance from the beginning that the scientist Michael Gregsten and his lover, Valerie Storie, were stalked, abducted and then attacked by a random killer - as Hanratty was described - has always seemed incredible.
One of the most implausible parts of the case against Hanratty - apart from an apparently sound alibi that he was in North Wales at the time of the murder - is what brought this urban-dwelling bit-part criminal to the cornfield near Maidenhead, in Berkshire.
Mr Alphon is unshakeable on this point. "There were other people involved. I know there were."
He believes that one of the other people was the murdered man's spurned wife, Janet Gregsten, who died recently, and at least one and possibly two others. He also maintains there was "corruption" which later prevented the wider truth coming out.
Mrs Gregsten, who certainly knew of her husband's affair, vehemently denied any involvement during a series of interviews with Paul Foot shortly before her death.
Mr Alphon insists: "I met her several times after the murder and it was always implicit between us that she was involved."
If the Scotland Yard report is as powerful and wide-ranging as rumours suggest, then the clearing of James Hanratty may not after all be the beginning of the end of the saga, but the start of a entirely new chapter.
The signs are that Mr Howard will make his decision soon, but Home Office sources, mindful of the case's long and controversial history, will not be drawn on a likely date.
Miss Storie, whose identification evidence helped convict Hanratty, told the Independent on Sunday last week that the findings were "of no concern" to her.Reuse content