It is 40 years since the bloodied bodies of three soldiers were found in a heap next to a reservoir in Scotland’s Pentland Hills.

A farmer came across the scene on 17 January 1985, after following a trail of blood in the snow from a crashed Land Rover he discovered with the engine still running.

With the IRA bombings at their height, the soldiers from Midlothian’s Glencorse Barracks were initially thought to be the victims of a terrorist attack.

But Tom Wood, then a police inspector who was one of the first on the scene, said the evidence quickly led them to a fellow soldier.

He has spoken to BBC Scotland News about his memories of the triple murder on the 40th anniversary of the so-called Glencorse Massacre.

The men were discovered beside a small derelict house at Loganlea reservoir, about 10 miles south of Edinburgh.

Staff Sgt Terrance Hosker, 39, and Pte John Thomson, 25, were in uniform. They were found alongside retired Major David Cunningham, 56.

“When I got there at the back of the house and at the bottom of the stairs were three dead bodies all lying on top of each other in a crumpled heap,” Mr Walker told BBC Scotland News.

“There was blood and cartridge cases lying around on the snow at the bottom of the stairs.”

He said they were shocked as it looked like a terrorist attack, which would have been the first of its kind in Scotland.

But very quickly the evidence pointed to Andrew Walker, a long-serving corporal instructor from The Royal Scots, who was 30 at the time.

Walker had been desperate for money. He knew that Thursday was pay day for the junior soldiers training at Glencorse Barracks, and they got paid in cash.

Every Thursday “regular as clockwork” a Land Rover and a crew of three soldiers would make the trip to the bank in nearby Penicuik.

No special security arrangements were made and the escort was unarmed.

Walker took a Sterling sub machine gun from the armoury and loaded it with ammunition he kept as spare.

Then, concealing the short barrelled weapon under his army coat, he flagged down the payroll Land Rover and asked for a lift back to the barracks.

Being known to the payroll crew, they allowed him to jump into the back of the vehicle.

He had planned to shoot all three of them deep in the Pentland Hills but as he hijacked them at gunpoint there was a scuffle in the back of the vehicle and Staff Sgt Hosker was shot.

Walker then also killed Maj Cunningham.

Next he forced Pte Thomson to take a detour into the Pentland Hills at Flotterstone and up to Loganlea reservoir.

There he made the young soldier help him drag the bodies to the back of the cottage.

However, if Pte Thomson thought his help would earn him mercy he was wrong.

Walker would leave no witnesses – Pte Thomson was executed, with a bullet in the head.

“This is a soldier shooting his brothers in arms. It’s diabolical, it really is,” said Mr Wood.

And all for just £19,000 – enough to buy two cars at the time.

Walker had been deep in debt and he had thought he could make it look like an IRA terrorist attack and robbery.

But his plan went wrong when his getaway vehicle skidded on the slippery path on his way out of the Pentland Hills to the main road – getting stuck in an icy ditch.

“He had probably planned to dump the Land Rover, clean the gun and quickly return to barracks before he was missed,” Mr Wood said.

“As it was, his plan and timescales were in tatters. He was now on foot with a bloodied uniform, an inconvenient gun he had to return, and a bag of cash he had to hide.

“Being skilled in the art of concealment he probably hid out for a while before making off across the snowy landscape.”

When it was safe he made his way back to barracks but by that time his movements were under scrutiny.

Shootings were uncommon in the east of Scotland, multiple shootings rarer still.

This was no ordinary crime, Mr Wood said.

“On the face of it, the crimes bore some of the hallmarks of a terrorist attack.

“The Provisional IRA were active on the mainland of Britain, they favoured military targets, and were always looking for funds.

“They weren’t averse to a bit of robbery in pursuit of their cause.”

However, there were problems with the terrorist theory.

“First the Provisional IRA had never carried out an attack in Scotland – seeing the Scots as Gaelic cousins they had privately declared Scotland ‘out of bounds’.

“Secondly, it was the habit of the IRA to claim responsibility for their attacks, so as to enhance their reputations as well as spreading terror.”

No-one had claimed responsibility.

Col Clive Fairweather, the commanding officer at Glencorse Barracks, worked with police officers investigating the murders.

An experienced military man, he had been second in command of the SAS operation that stormed the Iranian Embassy in London in 1980.

“No-one knew the Army or its soldiers better than Col Fairweather, and he quickly spotted the bullet cases in the back of the bloodied Land Rover,” Mr Wood said.

“He knew the type well, they were all 9mm parabellum cases, a calibre not usually favoured by terrorists but in common usage by the British Army for all its small arms, pistols and Sterling sub machine guns.”

The Det Ch Supt and Col Fairweather were beginning to suspect the robbery was an “inside job”.

A witness had also come forward to say they had seen four men in the Land Rover outside the bank – and three had been in uniform.

“It was a significant piece of information,” said Mr Wood.

There was also one gun that had been taken out of the armoury and replaced by Walker in the logs that day which matched with a bullet lodged in Staff Sgt Hosker’s shoulder.

“Each rifle barrel is different in minute detail and leaves distinct striation marks on the soft lead of a bullet head as it passes down the barrel,” Mr Wood said.

“The firing pins of individual weapons also leave distinctive marks on the detonator caps of bullet casings.

“It was best and conclusive evidence.”

Walker returned the gun before going absent without leave for three days.

He eventually returned to the barracks and attempted to bluster it out, denying all knowledge, and suggesting it had been the IRA that had been responsible but he was detained.

Shortly afterwards he was arrested when ballistic results arrived back from the lab.

Walker denied his crimes but a jury in the High Court in Edinburgh found him guilty of the murders.

Judge Lord Grieve recommended he serve at least 30 years in prison because of his “callous disregard for human life”. This was reduced to 27 years on appeal.

In 2011 Walker was released from prison on compassionate grounds, two years after a stroke left him severely disabled.

He died from a respiratory infection and suspected cancer in a care home in Wishaw, North Lanarkshire, in 2021 at the age of 67.

“Andrew Walker was a cold-hearted killer who set out to rob in the certain knowledge that to escape he would have to kill his three comrades in arms,” said Mr Wood.

“I suspect he was involved in some pretty brutal stuff in Northern Ireland because what he did was a cold-hearted execution.”

He doesn’t think Walker was mentally ill, he was “just a wicked guy”.

“He had absolutely no empathy for human suffering and that’s what makes me wonder what he had been exposed to early in his Army service.”

His planning of the crime was simple and audacious but poorly thought through, he added.

Mr Wood said, like many criminals, his plan of attack was much better planned than his plan of escape.

“As a military man he should have known that no plan survives contact with reality, yet when the first thing went wrong he had no back up plan,” he said.

“The simple act of skidding on an icy road derailed his brutal enterprise.”