Judge Lord Stewart is expected to ask the eight women and seven men on the jury to begin considering their verdict after hearing 50 days of evidence and lawyers' speeches.
The naked body of jeweller's assistant Ms Doyle, 16, was found just yards from her home in Ardgowan Street, Greenock, on the morning of June 2 1986.
At the High Court in Edinburgh yesterday Lord Stewart said there had been no suggestion this was anything but murder - the crucial issue in the case was who did it.
And, the judge warned: "Mistakes about identification have been made in court cases in the past."
Lord Stewart said jurors also had to be satisfied that DNA, which the jury has heard was found on Elaine's body, had got there during the commission of a crime.
John Docherty, 49, now of Hunters' Quay, Holiday Village, Dunoon, denies murder and claims that at the time he is alleged to have strangled Elaine Doyle, 16, he was with his parents - who are no longer alive - at their home in Anne Street.
Lord Stewart is expected to finish speaking to the jury today.