Man said he was a Good Samaritan attacked by ex-school friend, but forensics revealed a frenzied murder

When Andrew Hamilton was found dead in his flat, his neighbour and old school friend Christian Williams told police he died in a struggle after Andrew attacked him and he was forced to defend himself.

But something didn't add up.

"His T-shirt, jeans, trainers were absolutely covered in blood. They were soaked, wet through," said former Det Supt Iestyn Davies.

Williams called police on 18 July 2018 and officers found Andrew lying on the hallway floor of his flat in Bagillt, Flintshire, covered in cuts and bruises.

When questioned by police, Williams said he had helped Andrew back into his flat as he had been drinking, only to be attacked once inside and Andrew's death had been an accident.

But, as the forensic evidence in a new documentary shows, Williams' words were a story concocted to hide the grim truth.

This story discusses graphic details of death and violence that some people may find distressing

Williams, 44, lived in a ground-floor flat, and Andrew, 42, was his upstairs neighbour - they were old schoolmates with no history of tension.

Margaret Owen, Andrew's mum, was woken at 01:30 by a knock on her bedroom window.

"Two policemen were there. I knew it was Andrew. You hope against hope they're going to tell me he's in hospital."

Margaret had to go to her daughter Nicola's home and tell her Andrew was dead, but it wasn't until the afternoon that they learned someone had been arrested for his murder.

Jez Hemming reported on Andrew's murder for the Daily Post newspaper in north Wales.

"I remember one conversation I had with a contact within the police who basically said 'it's horrific. You actually wouldn't believe the detail of it when you see it'.

"And I have to say it turned out not to be hyperbole. It was really the case."

Williams gave police a detailed account of what he said had happened that night.

He had seen Andrew and his girlfriend arguing in the flats' car park after he returned from buying a bottle of wine.

Andrew, who was a drug user, wanted his girlfriend to drive him to a dealer, but she refused.

Williams said he intervened, gave them his bottle of wine then returned to the off-licence for another.

The couple were still there when he returned and he helped Andrew, who had been drinking, up to his flat after his girlfriend left, only for Andrew to turn on him once inside.

Williams said he had to defend himself and Andrew died in the struggle.

But the state of Andrew's body was telling a different story.

He had 95 separate injuries, including head injuries that went down to the bone, and he was so badly beaten he could only be identified by dental records.

Former Home Office forensic pathologist Dr Richard Shepherd said the bruising was so bad, it would have affected Andrew's internal organs.

One of his eyes had been severely damaged, with the cornea cut. "It was a vicious and brutal injury," said Dr Shepherd.

The extent of the damage to Andrew's body made it hard to tell which injury actually killed him.

This was apparent when Nicola went to see Andrew's body.

"I knew it was bad because of how little we could see of him. It was this bit [the centre] of his face and the rest of him was bandaged.

"We couldn't touch him. He was behind glass. We didn't even get to say goodbye to him."

It was vital for the police to know if all those injuries could have been caused by someone defending themselves - they needed to understand more about the two men's pasts.

Davies described Andrew as someone who had been arrested a few times in the past, but wasn't "a major player in the criminal world".

He had problems with drug addiction and had drugs and alcohol in his system when he died.

Williams, though, did not present as an obvious candidate for a brutal killer.

"We spoke to people at the flat, who knew him. They described him as a very polite individual and an intelligent person."

Williams went to Liverpool University as a mature student and studied engineering, with Hemming describing him as "generally a quiet, perhaps even shy, individual".

After his degree, he returned to Bagillt and worked part-time in construction and a pub.

Davies said: "We couldn't identify a motive in this case. There was no previous bad feeling."

Forensics established that the confrontation began in the bedroom and moved into the hall.

Blood spatter patterns on the wall showed Andrew was still alive when he was on the floor and had been lying down "severely injured for much of the attack," said Shepherd.

Back at the flat, police recovered a knife, a damaged saucepan, as well as its bloodstained handle, and the remnants of a bottle of gin.

"The neck of the bottle was covered in blood," says Davies.

The knife matched with cuts on Andrew's body and had caused about 25 of his injuries, while pathology showed the saucepan had caused the bruising and had been used with such force the handle snapped.

The broken handle itself may well have caused the horrifying eye injury, while the jagged cuts on his arms, legs and neck were a result of the broken bottle.

Williams' account of "self-defence" simply couldn't be true.

Shepherd said the use of three different weapons "wasn't consistent with a frantic fight for survival when the only injury to Williams was a cut to his hand".

Andrew, one of four siblings and a father of three, had struggled with drug addiction, including heroin, for much of his life.

Nicola tried to keep the extent of it from Margaret.

"I didn't want my mum seeing Andy in some of the states that I'd seen him... I just don't think she ever knew how bad things got for him.

He tried to kick his habit a number of times and entered rehab again around his 40th birthday, which Nicola had hoped "was the time he was going to be clean".

Davies said there can be stigma attached to victims who take drugs, the idea being "well, they must have deserved it... You can't think that way when you're a professional organisation like the police investigating a murder".

The narrative of Andrew as a drug-fuelled aggressor wasn't adding up.

The pattern of injuries on his arms and hands suggested someone trying to defend themselves and the sheer number of wounds on his body also pointed to "overkill".

Forensic psychologist Dr Catrin Williams says: "It's usually that somebody has lost control of their behaviour and hasn't been able to cope with their emotions which has led to this frenzied attack."

Police and prosecutors agreed with this idea and, at his trial, jurors finally heard the horrifying details of how Andrew died.

As he lay battered on the hall floor, Williams cut his throat so severely that Andrew bled to death in seconds.

On 31 January 2019, Williams was convicted of murder and is now serving a life sentence with a minimum of 23 years.

What sparked the frenzied killing is a secret Williams refused to divulge, with the judge telling him: "What caused you to lose your temper, only you know."

After the trial, Hemming, who covered the whole case, received a chilling video that suggested Williams had already showed signs of the hidden rage that exploded the night he murdered Andrew.

A fellow student filmed him in a Liverpool bar years before when he reacted after he thought people were laughing at him.

The footage shows him being restrained while shouting: "I'll kill you. I'll eat you."

Hemming said: "He absolutely flipped into a deranged state."

Appearances are not everything. As Hemming noted of Williams in court.

"He was just your average guy, dressed in average clothes, of average build with an average haircut.