The prosecution alleges that Mr Wilkin died in circumstances where he was violently assaulted between Killybegs and Slieve League, and his body was disposed of over the cliffs.
“Whether he was dead or not when he went over is undetermined, but you can be fairly sure he didn’t go over on his own,” Mr Condon said.
The prosecution’s case relies heavily on CCTV and DNA evidence, the court heard.
The court heard Mr Vial and Mr Wilkin were living together at the time, while Nikita Burns, who had no fixed abode at the time, had spent time in both men’s company in the run-up to the alleged murder.
It is the prosecution’s case that on the night of 24 June 2024, the three people were drinking together.
When they left a pub together in a car, they travelled west towards the village of Carrick and this is where the prosecution alleges the assault took place.
The court heard the car was then driven up to Slieve League and remained there for about 28 minutes, and later returned just before 03:00 local time.
On Sunday afternoon, the court heard Ms Burns and Mr Vial travelled to the town of Ardara, County Donegal, to the home of Alan Vial’s brother, Bruce Vial, looking for multi-purpose cleaner to clean the car.
After they left Ardara, the court heard that the car they were travelling in crashed, and Mr Vial was arrested for drink driving.
The court heard that Ms Burns was later arrested, and when interviewed, she initially denied all knowledge of what happened before admitting she helped clean the car, but denied the assault.
Mr Vial initially made an admission of assault but denied murder. The court heard he had visible injuries and said it was from a struggle.
The court heard that Mr Wilkin’s blood DNA was found in the car, while a pair of leggings found in a search turned up blood splatter that also was a match for Mr Wilkins.
Wet clothing and a pair of boots were also found; inside the boots was a phone belonging to him.
Also found at the scene on the cliffs was a bloody rock at the top of Slieve League and staining on it matches blood of the deceased.
Likewise, a white bloody blanket, a man’s watch, and a grey jumper with blood on it, found in the same search, matched his DNA.
The court heard that police also found a vacuum cleaner with blood on it at the home of Mr Vial’s brother.
BBC News