A fell runner who dumped his lover's body in a shallow grave on bleak moorland was convicted of her manslaughter today.
Adrian Muir killed 55-year-old grandmother Pamela Jackson by fracturing her skull during a row at her home, then drove her 120 miles to the hills above Halifax, West Yorkshire.
The stonemason had placed a bunch of flowers on her body in the shallow grave he dug on Soyland Moor in late March. The cold late Spring hampered police's efforts to find her, and her resting place was only discovered in May.
By that time 51-year-old Muir, who met Ms Jackson on a dating website, had been charged with her murder.
He continued to deny being the killer at his trial at Newcastle Crown Court, despite overwhelming evidence, and today the jury found him not guilty of murder but guilty of manslaughter.
His phone was tracked making the journey from Chester-le-Street to the West Yorkshire moor on the night she disappeared, and he had parked up close to where he dug the grave, 85m off the B6138 near Ripponden.
Muir, of Calder Terrace, Halifax, told the jury he knew "every inch" of Soyland Moor, having regularly run, biked and worked as a beater on grouse shoots there.
His fingerprint was found on the plastic bag the flowers in the grave were kept in.
In the days after killing Ms Jackson at her home in Chester-le-Street, County Durham, Muir was suicidal and recorded a series of messages on his iPhone, saying he could not continue to live and that there had been a "disaster".
A CCTV camera at a Chester-le-Street supermarket car park captured him cleaning the back seat of his Kia car with products he had just bought in the shop.
In the witness box, Muir, who cut a pathetic figure at times in his battle with experienced prosecuting barrister Andrew Robertson QC, claimed he had both been set up by the real killer, and was also a victim of coincidence and bad luck.
Ms Jackson, a mother-of-three adult sons who suffered from bi-polar disorder, had a volatile relationship with Muir, and had taunted him in a series of texts, calling him "ugly" and boasting she had a new lover.
The police investigation into Ms Jackson's disappearance and death was one of the largest Durham Police has ever undertaken.
It began on March 7, when her son Joe reported her missing. That was five days after her death because Muir had successfully hidden the truth until then.
As well as the countryside around her home town, teams of up to 40 officers searched the bleak Pennine moors in West Yorkshire.
They focused on Turvin Road, having analysed where Muir's mobile phone had been, and scoured either side of the 2.6mile long road.
The terrain comprised of thick grass, bogs, pools of water and heather.
During the search Turvin Road was closed for a week because of snow which lay several feet thick.
Other specialists joined the effort, including dog handlers and aerial reconnaissance from the National Police Air Support and the RAF.
As the jury's verdict was read out gasps and cries were heard from the public gallery, where the family of Ms Jackson had gathered.
Muir, who was dressed in a blue top with a white t-shirt underneath, remained silent as he was led out.
Judge James Goss QC said sentencing would be delayed to next week and, as the courtroom emptied, members of the family began to sob as they left.
Outside the court a police liaison officer said they were currently too upset to give their reaction.
In a statement, Durham Constabulary said the investigation into the killing of Ms Jackson covered a six-month period and they spoke to 167 independent witnesses.
They said 165 police officers and staff had been involved in the case and a total of 683 documents were produced.
"This was an incredibly complex and challenging case, especially as we did not have the victim's body for the first three months," said Detective Superintendent Ken Donnelly.
"It was a team effort in the truest sense, with staff from Durham receiving invaluable help from West Yorkshire Police and a number of other agencies."
Help was also received from South Yorkshire Police as well as units in the North West and Humberside region.
Mr Donnelly, who was the senior investigating officer, said Muir caused great pain to Ms Jackson's family by refusing to say where she had been buried and tried to thwart the investigation at every turn.
He described Muir as "a calculating and resourceful killer" who "sought every opportunity to cover his tracks and put the blame on others".
"He had every opportunity to tell us where he had buried the body, but he chose instead to deny Pamela's family the chance to recover her remains in a timely manner. This caused them untold anguish and pain," he said.
"At no stage did he ever have the decency to admit his guilt and confess what he had done. He did all in his power to frustrate the investigation and it took a huge amount of resources, plus sheer graft and dedication, to bring him to justice.
Mr Donnelly said he knew how to lay foundations and dig quickly and, as a fell runner, knew the area like the back of his hand.
"He had all the skills to dig the grave and construct a series of layers, like a lasagne, of soil, clay and other material.
"He went to great lengths to ensure the remains stayed hidden and, in fact, we had already searched that area three times before the weather improved.
"Small cracks in the ground then started to open up which meant the sniffer dogs could get a scent. Without that breakthrough, it is very possible the body might still be missing."