John Rafferty, 57, said he was on duty the night of Saturday, 15 October, 1977, and saw Christine Eadie and Helen Scott, both 17, leave the bar at around 11:20pm.
Giving evidence at the High Court in Livingston yesterday, Mr Rafferty said a man had offered the girls a lift, promising he would “take them where they needed to go”.
The former constable, who retired from Lothian and Borders Police in 1999 after 27 years, said he had helped Ms Eadie to her feet after she fell outside the pub on Edinburgh’s Royal Mile.
Mr Rafferty said: “I remember she had a dark coat with an imitation fur collar. I remember gripping her by the collar and helping her to her feet.”
Mr Rafferty said the girl was the person he now knew to be Ms Eadie.
He said he would not have left her on her own because it was clear she had “had a drink”.
But he said a blonde girl came forward – Ms Scott – and he realised they were together. Mr Rafferty said he then became aware of a man who was standing by the pub door staring at him. The former police officer said he managed to get a look at the man’s face for around ten seconds.
He said: “The girls were talking about what they were going to do. As the girls were talking, this man came forward and there was a debate about whether they were going to take a lift from this person or go on elsewhere.
“At some point, the man said ‘It’s OK, I’ll give them a lift’. The man had then come forward and started to interact with the girls and said he would take them where they needed to go.”
Mr Rafferty said he assumed the man was with the girls. He also described Ms Eadie as being “quite drunk”. He also said he remembered the man’s style of dress, which was out of fashion.
The retired constable said the man was wearing a V-neck jumper with red or blue stripes around the collar and cuffs and flared trousers.
He said: “The three of them started to walk to the corner. As they walked towards St Mary’s Street, I was conscious of another male joining the group.”
Mr Rafferty said he saw the group walking down St Mary’s Street – the two girls in front – before turning into a side street, Boyd’s Entry.
Lord Advocate Frank Mulholland, prosecuting, asked Mr Rafferty if he saw the group again. He replied: “No”.
In 2004, he had met two police officers who showed him photographs of 12 males to see if he could identify either of the men he had seen outside the World’s End pub in 1977.
Mr Rafferty had identified image ‘K’. Mr Mulholland said: “‘K’ it is agreed is Angus Sinclair, this man in the dock.”
The lord advocate asked Mr Rafferty how sure he was that the person in the photograph was the first man he had seen outside the pub.
“Not 100 per cent,” Mr Rafferty answered. “How sure are you?” Mr Mulholland asked. “60 per cent,” Mr Rafferty replied.
During cross-examination he was asked by Ian Duguid QC, defending, if he had concerns that he could have identified photo ‘K’ from a newspaper picture.
“That’s a possibility, yes,” he replied.
Sinclair, 69, is charged with assaulting, raping and murdering Ms Eadie and Ms Scott while acting with his brother-in-law Gordon Hamilton, who is now dead.
Sinclair denies the charges and has lodged a defence claiming the women consented to have sex with him and that he had been fishing on the banks of the Forth at Cockenzie power station when they were assaulted and murdered.
The trial continues