A jury has found Calderdale man Adrian Muir guilty of the manslaughter of his girlfriend Pamela Jackson but not guilty of her murder.

The fell-runner was accused of murdering his lover and burying her in a shallow grave on moorland near to the M62.

Adrian Muir, 51, from Calder Terrace, Halifax, West Yorkshire, denied murdering Pamela Jackson, 55, from Chester-le-Street.

The mother of three vanished from her home in March and her body was discovered on bleak Pennine moorland near Ripponden, in May.

Site where Pamela Jackson's body was found on moors at Blackstone Edge Road, near Cragg Vale
Site where Pamela Jackson's body was found on moors at Blackstone Edge Road, near Cragg Vale
 

By then Muir, a stonemason who said he knew every inch of the moors, had been charged with her murder.

The jury at Newcastle Crown Court was told he fractured her skull following a row at her home and he dumped her body 120 miles away that night.

He continued to deny being the killer despite overwhelming evidence.

Adrian Muir
Adrian Muir
 

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.

His fingerprint was found on the plastic bag the flowers in the grave were kept in.

Police searching for Pamela Jackson find body on Calderdale moors
Police searching for Pamela Jackson find body on Calderdale moors
 

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.

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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.

Muir denied the charges, claiming he loved Miss Jackson and that the real killer had tried to implicate him in the murder.

He will be sentenced at a later date.