On Air Now
27 October 2014, 18:37
Clothing found on the bodies of two teenage girls killed in 1977 contained DNA linked to the man accused of their murders, a court has heard.
A sample taken from clothing used as a ligature around the neck of Christine Eadie was analysed by forensic scientist Andrew McDonald in May this year and a low level mixed DNA profile was found, jurors were told.
He said in his opinion he was unable to exclude Angus Sinclair and Gordon Hamilton as "possible contributors'' to the profile.
Sinclair, 69, is on trial at the High Court in Livingston where he denies raping and murdering Christine and her friend Helen Scott, who were last seen at Edinburgh's World's End pub on October 15 1977.
Christine's body was found the following afternoon at Gosford Bay, Aberlady, while Helen's body was discovered a few hours later in a wheat field near Haddington.
Sinclair has submitted three special defences of incrimination - blaming his brother-in-law Gordon Hamilton, now dead; alibi - saying he was fishing on the banks of the Firth of Forth near Cockenzie power station at the time; and consent to sexual intercourse.
During the 10th day of the trial, the court heard how DNA samples from underwear found next to Helen's body were also analysed, with a mixed profile detected.
In a report prepared for the court, Mr McDonald said the chance of DNA from one of the samples coming from another person unrelated to Sinclair was in excess of one in a billion.
DNA found on other samples tested, taken from a ligature made of bra and tights around Christine's neck and a ligature of a belt and tights used on Helen matched that of Hamilton, he said.
The jury was told there was a one-in-a-billion chance the DNA could have come from anyone else other than Hamilton.
Mr McDonald, who told the court he worked for the Cellmark laboratory in England, said a MiniFiler technique was used to analyse DNA samples that could have degraded over time.
During questioning from Lord Advocate Frank Mulholland, prosecuting, Mr McDonald said his analysis of samples found "what you would expect from a mix'' of Sinclair and Hamilton's DNA on a bra round Christine's neck.
He said the strongest DNA components matched parts of Hamilton's profile and the "slightly weaker'' components matched Sinclair.
Under cross-examination from Ian Duguid QC, defending, he was asked whether sexual activity could have led to DNA samples being left.
Mr McDonald replied that would be correct.
The trial, before judge Lord Matthews, continues tomorrow.