A forensic scientist has told a murder trial that samples from 1977 were preserved in a "very good condition" when he came to analyse them for DNA.
Andrew Davidson, 46, said he believed scenes of crime work following the discovery of Christine Eadie and Helen Scott's bodies had been well-handled.
Mr Davidson, a forensic scientist with 22 years' experience, told how he carried out more than 18 months' work on the samples.
He is the last witness to give evidence for the prosecution in the trial of 69-year-old Angus Sinclair.
Mr Sinclair has been on trial at the High Court in Livingston for four weeks, where he denies raping and murdering the girls 37 years ago. He is accused of carrying out the attacks along with his late brother-in-law Gordon Hamilton.
Christine and Helen, both 17, were last seen at the World's End pub in Edinburgh on October 15, 1977. Their bodies were discovered in East Lothian the next day.
Mr Davidson, who works for the Chorley-based organisation Cellmark, carried out DNA analysis on items of clothing found on the bodies of the girls.
Among the findings was the conclusion that DNA evidence provides "extremely strong support for the view that Gordon Hamilton and/or Angus Sinclair were involved in the restraining and strangling of both Helen Scott and Christine Eadie, rather than an unknown and undetected individual or individuals".
Mr Sinclair has lodged three special defences - of consent to sexual intercourse, alibi and incrimination, blaming Hamilton.
Mr Davidson said he was not told of those special defences when he compiled his report in May this year.
He will continue giving evidence next week. The trial, before Lord Matthews, continues on Monday.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article