Kriss' body was found by the Clyde Walkway

Pauline McSorley said that the body she had seen had numerous stab injuries, was damaged by fire and had extensive mud stains on top of the burns.

She told the High Court in Edinburgh she believed Kriss had been assaulted, bled heavily and had been set alight.

Zeeshan Shahid, his brother Imran and Mohammed Faisal Mushtaq deny murder.

Ms McSorley, who works for Strathclyde Police, said she was called to the Clyde Walkway in the east end of Glasgow on 16 March 2004 while Kriss' body was still there.

In my opinion the deceased had been assaulted next to the logs beside the dirt track where he had bled heavily while mobile Pauline McSorley Forensic scientist

Describing the scene, she said a dirt track passed an area where trees had been felled and there were heavy blood stains on a log which was also superficially charred.

Other blood stains were found on grass between the body and a dirt track passing the logs. There was also scorched fabric and scorch marks on the grass.

Advocate depute Mark Stewart QC, prosecuting, asked if she had been able to reach any conclusions.

Ms McSorley told him she thought someone had "bled freely" on the log and adjacent track.

"In my opinion the deceased had been assaulted next to the logs beside the dirt track where he had bled heavily while mobile," she said.

"He had been set alight and had made his way down the grass slope."

Shoe found

Ms McSorley was also asked, two days later, to examine a burned-out Mercedes car. She said she found blood stains on the bonnet and wing and the blood had been dried by the heat of the fire.

A colleague of Ms McSorley said that a left training shoe found in the car had a similar sole pattern to one worn by Kriss Donald, but it was too burned to allow a size comparison.

Earlier, a witness who had been in the cell block at the court initially refused to give evidence.

David Beaton, 21, said he had been taken to Glasgow Sheriff Court on 6 October last year.

When asked by Mr Stewart about a statement he gave to the police he stepped out of the witness box and refused to go back in.

Cell 'threat'

Judge Lord Uist told him several times: "You must return to the witness box."

An hour later the court heard that Mr Beaton wished to return to the witness box.

He told Mr Stewart: "I just heard somebody shouting ... at the Reliance officers."

When asked who was shouting Mr Beaton pointed to the dock and said: "Them there." He now has to return to court on Tuesday to face a possible contempt finding because of his behaviour.

Another witness, David Bates, 21, said he had been taken to the cell area and heard someone shout "we will murder you as well".

He told Mr Stewart he could not see the man who had shouted because he was in a cell.

Zeeshan Shahid, 28, his brother Imran Shahid, 29, and Mohammed Faisal Mushtaq, 27, all deny the racially aggravated murder of 15-year-old Kriss.