A body found in woodland was so badly burned it was hard to tell whether the corpse was male or female, a murder trial has heard.
The High Court in Edinburgh has heard how trail bike enthusiast Stuart Bell, 45, chanced on the charred remains of teenage student Zoe Nelson while riding near his home.
A police officer told the court how the horror find and the surrounding shrubbery were examined for clues.
"It was very gruesome," said Detective Sergeant Clifford Neil, one of the first officers called to the scene on Monkey Hill on the outskirts of Wishaw, Lanarkshire.
Zoe, 17, lay on a pile of blackened papers, the court heard, with plastic over her face.
Near one foot was a bottle which chemists tested to see if it contained any "accelerant" which might have been used in the burning.
Also near the body was a small, red, plastic Mexican hat. It matched the cap of a brand of tequila, said the detective, and an empty bottle was found on the other side of a small path.
A painstaking search during the days which followed also revealed a black trainer with pink trim and women's hairbands. One of the wrists bore a tattoo.
Det Sgt Neil said he was led to an area of woodland near Branchalfield Drive, Cambusnethan, Wishaw, last May 23.
He said: "I was trying to make an assessment of the body lying there. Was it male or female was my first thought. I was trying to assess what had happened, what had actually taken place here?"
The trial also heard of a late night fire in the Lanarkshire town the previous night.
Mrs Roberta Gold, 61, of Cambusnethan, Wishaw, said she was closing her bathroom window when she saw the red hot glow among trees in a nearby field.
She said it was not unusual for youths to gather and light fires in the area, or for dry grass to be burned in the field - but this fire looked different.
Mrs Gold said: "It caught my eye because it was a very distinctive red. It wasn't like a grass fire where you are getting a lot of sparks and trails of smoke. It was red hot and there were small flames coming from it."
Mrs Gold continued: "The main redness looked as if it was something solid."
Robert Bayne, 21, denies attacking Zoe with a knife at the spot known locally as Monkey Hill, putting a plastic sheet over her head to restrict her breathing and then setting fire to her last May 22,
Bayne also denies an earlier attack on Zoe, of Crindledyke Crescent, Newmains, by punching her on the head and scratching her and, on another occasion, committing a breach of the peace by threatening her.
It is also claimed that after the murder he tried to cover up his alleged crime by setting fire to Zoe's body, washing his clothes, dumping her mobile phone and telling police that someone else was responsible.
A charge of attempting to defeat the ends of justice also alleges that Bayne told Zoe's sister, Laura Anne Nelson, 16, where Zoe's body lay, but threatened to kill her if she reported what she had seen.
Bayne denies all the charges against him, including an alleged assault on a detective and repeatedly stealing alcohol from an Asda store in Morningside Road, Newmains, on the day Zoe is said to have died.