Stewart Blackburn denies murdering 17-year-old Jessica McCagh
A murder trial has heard that a 17-year-old girl who died after having petrol thrown on her and being set on fire was probably kneeling at the time.
Graphic images of the injuries to Jessica McCagh's body were shown to jurors at the High Court in Livingston.
They revealed that the teenager suffered between 80% and 85% burns as a result of the incident on 25 April.
Stewart Blackburn, 18, from Arbroath, has admitted culpable homicide but denies murder.
Pathologist Dr David Sadler, of Dundee University, who carried out an autopsy on Miss McCagh on 26 April, described her as a healthy teenager who died as a result of receiving "unsurvivable" burns.
He said that the major mechanism of death was widespread burning of her skin, leading to subsequent acute complications, combined with smoke inhalation and carbon monoxide poisoning.
The court heard that Miss McCagh had received "full thickness burns" over most of her body, with only areas of skin covered by one sock and her underwear unaffected, together with the front of her right shin.
He said the pattern of burning was consisted with "an accelerated clothing fire", caused by "some liquid fuel" in contact with Miss McCagh's clothes.
He added: "The most noteworthy thing about the pattern of burning was that there was almost complete sparing of the front of the right shin, which might lead us to believe she was kneeling or partly kneeling when the fire was set."
He confirmed that one of the preliminary ideas he had been informed of by the police before the post-mortem examination was that Stewart Blackburn had poured petrol on her and set her alight.
When he said he found it difficult to estimate the volume of accelerant that might have been used, the solicitor-general Frank Mulholland QC, prosecuting, held up a tumbler he was sipping from and asked: "You see some water in this glass?"
Dr Sadler replied: "I'd envisage a much larger volume than in a glass."
Pointing to a carafe beside mounds of law books and documents, he added: "More like the volume of water in that jug."
Dr Sadler said he also noted minor bruising on Miss McCagh's scalp, above the eye and towards the hair line, which could have been caused by "a fall, a punch, or a slap."
Consultant plastic surgeon Mr Anas Hassan, who treated Miss McCagh at Ninewells Hospital in Dundee in the hours after the fire, said that large areas of her skin had been burnt completely.
He said an anaesthetics team made her comfortable, and she died in the presence of her family in the early hours of the afternoon on the same day as the fire.
Dr Elizabeth Skelly, who treated Miss McCagh on her arrival at the hospital, also treated Mr Blackburn for minor burns to the back of his legs.
Asked if she took a "history" from Mr Blackburn, she replied: "I have document that he said he lit a cigarette when a petrol can was standing next to the bed and that set the bed on fire.
"He managed to run out of the house immediately. His girlfriend was in bed at the time."
Mr Blackburn denies murdering Miss McCagh by pouring petrol over her and a bed in the flat which they shared, and setting her alight.
The trial, before Lord Bracadale continues.