Teenage girl lured ex boyfriend to his death before lover brutally murdered him

On 7 June 2018, the body of 27-year-old Steven Donaldson was discovered in a nature reserve park in Scotland.

The oil worker had been stabbed 26 times before his remains were hidden underneath his own car, a BMW, which was subsequently torched.

In the weeks that followed, investigating officers determined that the Arbroath local - who had a passion for motoring - had been lured to the area by his ex-girlfriend, Tasmin Glass, before her new lover Steven Dickie and his friend Callum Davidson viciously ended his life.

Now, what became one of the UK's most harrowing murder investigations is being rehashed in a brand new Channel 4 documentary, which sees officers recall how it was they eventually pinpointed the killer.

Steven was murdered in June 2018. (Channel 4)

Upon retrieving and identifying Steven's body, police were initially at a loss over who would have a motive to murder a man who was seemingly so well loved by those around him.

This was because the villainous trio had partially wiped the digital trail they'd left behind during the run-up to the killing.

Glass, Dickie and Davidson had also been careful not to leave any forensic evidence that investigating officers could follow up by torching Steven's car.

This meant that police were unable to delve into commonplace leads, like DNA on clothing, or the victim's phone records.

As the new documentary explains, it was only after police looked into Tasmin's whereabouts on the night that the truth began to become apparent.

Glass claimed she'd been with Dickie, Davidson and Davidson's girlfriend Claire Ogston on the night of the murder.

Then she said she'd gone to meet Donaldson at a car park in Kirriemuir, but he never showed up.

She insisted that she'd returned home to bed - something which was confirmed by her Wi-Fi router - whilst her Apple Watch confirmed she'd gone to sleep just after 11pm.

Tasmin wasn't an initial suspect. (Channel 4)

Unconvinced, the detectives the took a punt by acquiring Dickie and Davidson's phones after which they achieved a huge breakthrough in the case.

Despite the pair claiming to have been at home in bed after midnight on the evening Steven was killed, call data from their phones suggested not only that some content had been delated, but that they'd been out in the centre of Kirriemuir between 12.39am and 12.51am.

Furthermore, the Health app on Dickie's phone showed him as having carried out the equivalent of climbing 11 flights of stairs or other significant exercise in the middle of the night.

This correlated with a coroner's report that Steven had died after his spinal cord was cut with repeated blows to the back of his head or neck with a weapon.

After subsequently reviewing CCTV footage from the night in question, Davidson could be seen riding his bike through the town centre at 2am.

After acquiring the bike, traces of Steven's blood were discovered on the handlebars.

Steven Donaldson was murdered by his ex's new lover (Police Scotland)

They subsequently discovered that Steven's ex had owed him a significant amount of money prior to his murder.

According to court records, Tasmin been indebted to the victim to the total of £1,000 for a car she'd had written off, and he'd been hounding her for payment.

After all three were arrested, officers determined that Tasmin had led Dickie and Donaldson to the area of Peter Park park in which she'd planned to meet up with her ex.

The two boys then took Steven to the nature reserve where they brutally murdered him, while Tasmin returned home for a peaceful night's sleep.

After an emotional trial, Dickie and Davidson were handed life sentences for the murder of Steven Donaldson, while his ex-girlfriend Tasmin has sentenced to 10 years behind bars.

In November 2019, Dickie died while still in prison. Glass, meanwhile, is soon due to be considered for parole.