A teenage murder victim may have been strangled with a stocking, the World's End trial has heard.
Helen Scott and Christine Eadie went missing after a night out
The High Court in Edinburgh was also told a footprint may have been left on Helen Scott's neck by her killer.
Retired Professor John Mason, who carried out a post-mortem on Ms Scott 30 years ago, said her injuries were consistent with "manual strangulation".
Angus Sinclair, 62, denies raping and murdering Ms Scott and her friend Christine Eadie. Both were aged 17.
Prof Mason, 87, said he had found an imprint left by a stocking which had been tied around Ms Scott's neck and four bruises left by fingers under her jaw.
He said: "They are the injuries you would expect in manual strangulation."
The professor said a row of horizontal scratches in front of and behind the dead girl's left ear had been left by "something patterned".
"The most likely thing with that sort of pattern is the sole of a shoe."
He said perhaps the marks were caused by a sole and heel, with the instep of the foot over the ear. Some force like a stamping motion would have been needed, he added.
The professor also witnessed the post mortem examination carried out at the same time on Ms Eadie.
The cause of death was again recorded as asphyxia following strangulation by ligature and gagging of the mouth in her case.
The trial has heard that the bodies of the two 17-year-olds were found in separate locations in East Lothian in October 1977.
Ms Eadie was naked and had her underwear stuffed in her mouth. Partially clothed Ms Scott was covered by a coat.
A former policeman had earlier told how he helped one of the victims to her feet outside the World's End pub in Edinburgh shortly before she disappeared 30 years ago.
John Rafferty, 50, said Ms Eadie then walked away with a "shifty" looking man and her friend Helen Scott.
Mr Sinclair, 62, denies raping and murdering the girls after forcing them into a vehicle near the pub in the Royal Mile.
He claims his brother-in-law, Gordon Hamilton, who has since died, was the killer.