A man at the centre of one of the UK's longest alleged miscarriages of justice is making a fresh bid to clear his name after a legal fight spanning more than four decades.
Paul Cleeland, 75, of Kent, spent a total of 26 years behind bars for Terry Clarke's 1972 murder in Hertfordshire.
Lawyers claim nearly all the evidence against him has been discredited.
Damian Collins MP believes the case may be "one of the last great miscarriages of justice from the 1970s".
Suspected gangland boss Mr Clarke, a friend of Cleeland's, was shot twice in Stevenage after returning home from a bar on 5 November 1972.
Cleeland always insisted he was innocent and that he was at home with his wife when Mr Clarke was killed, but legal challenges over the years failed.
In the Administrative Court on Thursday, he sought permission for a judicial review of a decision by the Criminal Cases Review Commission (CCRC) not to refer his case to appeal.
Mrs Justice McGowan reserved judgment, telling the court there was "material that could benefit from a greater review by me before reaching that decision".
She said: "I know how aggrieved Mr Cleeland is and I know how deeply concerned and troubled he is.
"I don't want my decision today to lead him into any false hope. You mustn't take this as meaning one thing or another."
The CCRC was not represented at the hearing.
Speaking outside the court afterwards, Cleeland said: "All I want is for them to say: 'Mr Cleeland we're sorry.'
"If they wanted they could have closed this down today."
'I know in my heart'
Retired Kent detective superintendent Nick Biddiss said forensic work had advanced "by light years" since the Hertfordshire force investigated the case in the 1970s.
But he also pointed out a number of judges had decided there was nothing wrong with Cleeland's conviction.
Now out of jail for 20 years, Cleeland, who represented himself at his trial in 1973, said he was still fighting because "it was wrong".
He said: "I was the only one who told the truth. I know in my heart I was telling the truth.
"It's when you're the only one telling the truth and people look at you and go 'that poor fellow'."
The pensioner, a twice-married father-of-five, now lives alone in sheltered housing in Folkestone.
He has said he cut ties with his family after he was jailed so they could live their lives.
Cleeland said his late mother and aunt continued visiting him in prison and campaigning for him into their 70s, adding: "They drove the media and MPs mad."
Explaining their ashes had been scattered at sea, he said: "I want to be able to stand by the sea and say to them 'we've done it'."
The National Archives at Kew holds about a dozen files on the case, most of them closed - although three open files contain documents from Cleeland's first trial and retrial.
Cleeland's barrister, Edward Fitzgerald QC, has told the Administrative Court the original trial heard evidence Cleeland had a motive to kill; bought the gun and tried to obtain cartridges; that police heard incriminating conversations; and a forensics expert found lead contamination consistent with gunfire on his clothing.
But in a note to the court seen by the BBC, the barrister said: "Almost every one of these strands of evidence and all of the forensic strands have now been discredited."
Mr Cleeland's solicitor, Ricky Arora, said: "Mr Cleeland's case is one of the longest running miscarriage of justice cases in the UK but sadly his applications to the CCRC have not been dealt with adequately and therefore he continues to fight to clear his name."
He said if the matter was considered properly and referred to the Court of Appeal, there was "no doubt" Cleeland's conviction would be quashed, "given everything we have".
Folkestone and Hythe MP Damian Collins has raised his constituent's case with the Home Office and CCRC.
He said: "I believe that a good deal of the evidence that was presented in his original trial has been shown to be flawed and therefore I don't believe the conviction is safe.
"I think it's right that his case should go back to the Court of Appeal and I believe there are strong grounds to have his conviction overturned.
"I believe Paul's case could be one of the last great miscarriages of justice from the 1970s."
Following the Administrative Court hearing, he added that it could have "huge ramifications for a whole range of other trials in the 60s and 70s that relied on similar evidence".
"If Paul is successful in getting his conviction overturned there should be a full review or inquiry."
That decade saw a series of high-profile miscarriages of justice which included the cases of Judith Ward, the Guildford Four, Maguire Seven and Birmingham Six and directly led to the formation of the CCRC.
Still fighting after 45 years
- 1970s: Terry Clarke is shot and killed on 5 November 1972. Cleeland is convicted at retrial in June 1973 and jailed for at least 20 years. His first appeal fails in 1976.
- 1990s: Cleeland is released in September 1998 having served 26 years including time in custody before conviction. In October 1998, the newly-established CCRC refuses his first application to refer the case to appeal.
- 2000s: The CCRC decision is overturned and the CCRC refers the case to the Court of Appeal but a second appeal fails in 2002. The CCRC refuses Cleeland's second and third applications in 2003 and 2008.
- 2010s: The CCRC refuses a fourth application in 2013. Damian Collins MP makes the fifth application, which is refused in 2017. On Thursday, Cleeland will go the Administrative Court to seek leave for a judicial review of the CCRC's decision.
Cleeland has the backing of Paddy Hill, one of the Birmingham Six, who founded the Miscarriages of Justice Organisation (MOJO) after his own wrongful conviction for the 1974 Birmingham pub bombings was quashed.
Mr Hill, who served time in jail alongside Cleeland, said Cleeland served five years over his minimum tariff because he refused to admit any guilt.
"Any innocent man who keeps protesting his innocence is down for a hard time," he said. "They move them from jail to jail all the time.
"It's unbelievable. You become disorientated. They drag you out of the cell at any time. The next thing you know you're 300 miles away, with no explanation, no nothing.
"It had a great impact on all of us. You find it very hard to settle down afterwards. You're institutionalised."
Mr Hill said it had been well-documented that wrongful imprisonment caused irreversible psychological damage.
"You find it very hard to come out and fit into society. You don't feel a part of it. You can't handle relationships," he said.
On hearing Cleeland was making a further attempt to clear his name, Mr Hill said: "Quite rightly so. If you're innocent, you'll fight until you're dead."
It is thought the Clarke family later moved to London. The BBC has not been able to contact them.
The CCRC said it could not comment while proceedings were under way.
Mr Biddiss said: "Obviously a case that is now 46 years old will have difficulties as far as witnesses are concerned as I suspect some will now be deceased and forensics have been advanced by light years - DNA being one that no doubt would have been helpful if available at the time."
He added: "No doubt Mr Cleeland will have convinced some prominent individuals, including his now local MP, as to his innocence, but he didn't have any success with the judge and jury at his retrial when he was subsequently convicted.
"As for Mr Cleeland putting forward the fact that he spent an extra five or six years in prison because he would not admit his guilt, he could hardly do anything else given his protestations throughout the whole affair.
"It appears that a number of High Court judges have had a look at his case and none thought there was anything wrong with his conviction."