An Ayrshire building firm boss brutally murdered a worker amid fears he was going to report him to police.
George McMillan choked Michael Thomson, 46, with cable ties at his business in Ayr in July 2020.
The 56 year-old ex-soldier then ferried Michael's body in the victim's Ford Fiesta before leaving both at a lay-by of the A77 road.
Jurors heard how a large-scale cannabis factory had been set up in the unit beside where McMillan's Style Builders firm was based.
Police carried out a raid there on June 11, 2020 — weeks before the death.
Prosecutors told how McMillan was a "trusted member" of those involved in the drug farm.
He faced arrest, but there had then been a plan to divert blame on his labourer Michael.
However, McMillan flew into rage when he learned Michael may instead "shop" him to police, leading to the horrific killing.
McMillan was today found guilty of murder, attempting to defeat the ends of justice and cannabis supply.
It emerged he already had a lengthy history of violence and drug crimes.
Lord Beckett today sentenced him to a minimum 21 years after the trial at the High Court in Glasgow.
The judge told McMillan: “It is plain that this was a pre-meditated murder of the most callous kind.”
Jurors heard how McMillan had been "actively involved" in the cannabis factory before police swooped.
He was then due to be quizzed by detectives about it in late July 2020.
But, a plan was hatched by McMillan and others to "foist blame" on Michael, who was hassled to go along with it.
McMillan later discovered, however, that his worker "threatened to shop him" for the cannabis cultivation.
In his speech to jurors, prosecutor Euan Cameron said the thug was then described by one witness as "really angry".
Mr Cameron: "He was so angry he looked as if his eyes would pop out."
The advocate depute said Michael had gone from a person McMillan could "exploit" to becoming a "threat" to his freedom.
Mr Cameron: "The existence of a possible motive could be viewed as significant."
The men ended up together at McMillan's business on the night of July 24, 2020.
It was there McMillan used cable ties to strangle Michael before dumping his remains into the back of the Ford Fiesta.
Just after midnight, the killer drove to the lay-by between the Holmston and Whitletts roundabouts in Ayrshire.
It is thought he planned to travel further afield, but feared the Ford was going to break down.
McMillan left both car and body — ditching the keys and Michael's phone — before traipsing back to Ayr in the lashing rain.
He also changed his clothes and tried to delete footage from his firm's CCTV.
McMillan returned to the area a number of times in his flat-bed truck — although told jurors he was only out checking if a light was working in the vehicle.
Michael's body was discovered still in the Ford later that day before a murder probe was sparked.
The court heard McMillan had claimed to his partner Caroline Williamson that he had received a "suicide" letter Michael had apparently written before his death.
Mr Cameron put to her: "Did you think something was not right about it?"
Caroline said: "At the time, I did not think it seemed like a suicide letter...there were a lot of a spelling and grammatical errors, which made it seem off."
She knew Michael as being more "articulate".
McMillan denied the charges and had lodged a claim of alibi for the murder.
He insisted he had not been in Michael's car and had been out walking a dog around that time.
It emerged he had four previous high court convictions including a six year jail term for drug dealing.
Ross Brown, defending, said McMillan had previously served in the army for five years including tours of Northern Ireland.
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