Ross Willox, 42, killed Emma Faulds, 39, after having a party with her at his Moncton, Ayrshire home on Sunday, April 28, 2019.
Ms Faulds, a youth worker, was reported missing by her family on April 30, 2019, two days after she was last seen.
Her body was found six weeks later in Glentrule Woods, Galloway Woods, Dumfries and Galloway, after a major search involving specialist officers and search dogs.
The couple had known each other from the time they worked together at Kilmarnock Prison.
Ross Willox denied the charges, but was found guilty of murder and attempting to overthrow justice following a High Court trial in Glasgow in May.
He was sentenced to life in prison and said he must serve a minimum of 20 years when he returned to court for his sentencing on Tuesday.
Judge Lord Mulholland told him: “You were convicted of the murder of a young woman, Emma Faulds .
“Only you will know what happened in your house that night, as a result of which you killed your friend.
“By killing her, you created an elaborate scheme to cover up your crime.”
He said Willox placed Ms. Folds’ body in a shallow grave, covered it up, and tried to make sure it decomposed faster by placing it in a moist place.
The judge said, “You hoped he would never be found and her devoted family would have to spend the rest of their life wondering where she is and whether she is alive or dead.”
Willox was convicted of the murder of Miss Faulds in an unknown manner at a home in Moncton, Ayrshire on April 29, 2019, and in an attempt to obstruct justice in various ways between April 29 and May 8, 2019.
He hid the dead body in Moncton and elsewhere, and then threw his friend’s naked body into the ground at the end of a remote forest trail in Glentrul Forest, hiding it in dirt, moss and other vegetation.
On April 30, Ms. Faulds’ parents were visiting relatives in Brighton when her mother received a call from Emma’s employer at the Kibble Education Center in Paisley to say that she had not shown up for work.
Margaret told the jury: “We were worried because it was completely out of character. She was in touch every day. We knew something was wrong. ”
Police eventually broke into Emma’s home in Kilmarnock that day, finding that only her beloved dog, Vesti Maverick, was unusually lonely.
A call was made throughout the country to try to find her.
Her younger sister Miriam flew in from her job as a nurse in Abu Dhabi to join the desperate hunt.
Prosecutor Paul Kearney asked the 34-year-old man if Willlocks had helped with any searches.
She replied, “Never. I thought it was strange. Why shouldn’t he try to find her?
After Ms Folds was reported missing, Willlocks told police that he walked with her in his apartment, but said that they then drove her car to her apartment in Kilmarnock, Ayrshire, where he said, he left her healthy and well.
However, police were suspicious of his movements when they found CCTV footage of a man driving her car back to her street.
They then found CCTV footage of Willlocks driving his Mercedes Jeep through Girwan on April 29 towards the Galloway Forest, a region where he had previously worked building wind farms.
He was also captured by CCTV in Era before heading out into the woods as he went to various stores buying bleach bottles, rubber gloves, shower curtains, cans of outdoor disinfectant and waterproof pants.
Taken together, police said it painted a suspicious picture of Ross Willlocks in relation to the disappearance of Ms. Folds.
The Galloway Forest covers an area of about 700 square miles, however, using special techniques, the police were able to focus on the search area.
Using cellular analysis from Willox phones superimposed on video surveillance data, as well as time and distance mileage with cars, officers were able to narrow the search to 10-15 square miles, and the body of the missing woman was found on June 12, 2019.
Willox, who befriended Miss Folds when they both worked at HMP Kilmarnock, was arrested on May 8, 2019 and later charged with her murder.
Judge Mulholland told Willox, “You weren’t as smart as you thought.”
He sentenced him to life imprisonment for at least 20 years on murder charges and six years for trying to overthrow justice in order to run at the same time.
Donald Findlay, QC representing Willox, said it would be inappropriate to express any remorse on behalf of the 42-year-old man when Willox says he is not responsible.
He said that although what happened would never be known, it looked like everything was fine when the drugs were brought to Mr. Willocks’ house early that morning.
Mr Findlay said: “He is not the type of person I would expect to find guilty of murder, murder of someone he knew and cared about – they cared for each other, not in any romantic sense, but as friends. …
“Something catastrophic happened early in the morning and one life was lost.”
Detective Inspector Peter Crombie, Deputy Chief Investigator for the Investigation, previously described Willox “a selfish, arrogant monster” and said the motive for the crime had not been established.