The unanswered questions that surround a dad's 1999 murder

Handyman Mick Marples was fatally punched outside a Sheffield clubhouse in June 1999, less than 24 hours before the Father's Day his son would come to grieve. A miscarriage of justice saw a "Good Samaritan" wrongly sent to prison for the attack and a court's decision to keep evidence secret means the unsolved case remains shrouded in mystery.

At Sheffield Trades and Labour Club on a Tuesday lunchtime, a stone's throw from the city's close-knit Park Hill estate, long-standing regulars are dotted around the main bar area. Some have met up with pals, while others drink quietly at tables alone, nodding to familiar faces as they come and go.

Talking to the BBC in a side room at the club, friendly landlord Sean Duddy recalls Mick Marples as "a very easygoing bloke".

"He was chatty," Mr Duddy says. "Everybody knew him. He wasn't full of himself. You can get some characters like that. He loved his pool."

Well-known for his love of fishing, Mr Marples had been a regular at the Trades and Labour Club for decades.

After popping in for a couple of pints on the evening of 19 June 1999, the father-of-one was found lying on the ground of the club car park shortly after midnight, with blood pouring from his head and face.

His home was so close to the club - a matter of yards - that the camera on the BBC Look North coverage of the incident at the time was able to pan directly from the outside of the venue to his property on Stafford Street.

The following day, Father's Day, his life support machine was turned off in hospital.

"I've never celebrated Father's Day since," Mr Marples' son, who was about to turn 27 the following week, says.

"I've never celebrated my birthday since. It's pointless. They just turned the machine off and that was it."

Mr Marples had been a pipe fitter for the Channel Tunnel when it was built several years earlier, but it was personality rather than profession which defined him to friends and family.

"If he could fish seven days a week, he'd fish seven days a week," his son, who we are calling 'Paul' because he did not want to give his real first name, adds.

"There were 250 people at his funeral. It was absolutely jam packed. The handshakes seemed to be never-ending."

Three years later, a man named Shaun Booker was convicted of Mr Marples' manslaughter following a trial at Sheffield Crown Court.

The prosecution argued Mr Booker was guilty on the basis of blood splatter found on his clothes.

He had been at a private function - a football presentation ceremony - in another part of the club that night and did not know the victim.

A trained first aider, Mr Booker had protested his innocence, insisting he had found the victim lying on the ground and that the blood had stained his shirt as he tried to help Mr Marples.

Mr Booker served a 21-month prison sentence before his conviction was overturned by the Court of Appeal in 2006.

He would tell the Sheffield Star afterwards how his "world fell to pieces" upon going to jail, where he shared a cell with an armed robber.

Abigail Rolling, who was Mr Booker's defence solicitor during the case, describes her client as the "quintessential Good Samaritan".

"It's not just an innocent man being convicted of something they hadn't done," she says.

"It's someone who went to help a stranger."

Ms Rolling, who describes Mr Booker's conviction as the "lowest point" in her professional life, says the defendant and victim "were strangers".

"There was no evidence their paths ever crossed that night," she explains.

"There was no motive for an assault. No witnesses. No CCTV."

In a bizarre twist, however, a panel of three judges ruled it was "not in the public interest" to disclose why they were now so certain he was not the killer.

The previous year, the CPS had written to his defence counsel, effectively encouraging them to appeal the guilty verdict. It's a move Ms Rolling describes as "unprecedented" in the legal world, as in almost all appeal cases the burden is on the defence to gather new evidence that might overturn a verdict.

She points out that such a decision by a court to withhold the evidence is "normally - not exclusively - but normally associated with high level terrorism and national security stuff" rather than a man punched outside a club.

Despite the emergence of the new evidence, which remains a mystery to this day, South Yorkshire Police say no-one else has ever been arrested or charged over Mr Marples' death since Mr Booker's acquittal.

Paul speaks of a sense of relief that he had made up with his dad just weeks before his death, after a row meant they had kept their distance from each other for a "few months".

But that relief is swamped by grief and frustration that the case remains unsolved.

"I was hoping on the 25th anniversary we might get answers, but we didn't," he says. "The longer it goes on, the more I think someone will take it to their grave.

"What makes it harder for me is because I used to drink in a lot of pubs, I might have sat beside that person, laughed and joked with them at a bar, not knowing I'm with the person that's done it. That's what winds me up most."

He adds: "I still don't know how they can sleep after all these years knowing what they've done. Not just killing a bloke but taking him from a family.

"They've ruined that family's life. Nobody knows why."

Mr Duddy says the "atmosphere was down" at the Trades and Labour Club in the weeks and months after it happened.

The incident remains a topic of conversation at the venue.

Mr Duddy, citing the fact "150 people were here" on the night of the murder, believes "someone must have seen something".

"In them days there was no CCTV like we have now," he adds.

"Technology has moved forward."

Mr Booker declined to give an interview when approached by the BBC, saying he wished "not to reopen old wounds".

In a statement, however, he said: "I still hope that eventually the truth will out, so that Michael's family can know the truth and the real person that was at fault. The family has been lied to and deceived by people in a system who hold the highest power, but who failed us all."

Mr Booker added: "Michael's life will never be returned, and I will never get the time back that I served. I served time for being a good person and trying to save someone's life. This ruined mine and my family's lives and haunts me to this day.

"I now have grown children and have a good life and have moved on to a better place since the overturning of my conviction."

Dave Stopford, joint head of the major incident review team at South Yorkshire Police, said: "Our most recent review into this case took place earlier this year and any new intelligence or information is investigated as it arises.

"Families of the victims of homicides are informed of any significant updates.

"Our thoughts remain with everyone affected by Michael's loss and I want to reassure his loved ones that this case does remain active.

"If you have information which may help us solve Michael's murder, please report it to us online or by calling us on 101."

The Ministry of Justice refused to confirm whether or not Mr Booker ever received compensation for his time in prison.

The Crown Prosecution Service said it was unable to comment.

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