World's End murders: Accused's DNA 'matched samples found on ligatures'
The World's End murder trial jury has heard that DNA from the accused, Angus Sinclair, matched samples found on ligatures and clothing on both victims.
Mr Sinclair, 69, denies raping and murdering 17-year-olds Helen Scott and Christine Eadie in October 1977.
Forensic scientist Andrew McDonald said the chance of the DNA coming from another person unrelated to Mr Sinclair was more than one in a billion.
New techniques mean samples that have degraded can now be analysed.
Mr McDonald told the High Court in Livingston he was unable to exclude Mr Sinclair and his brother-in-law Gordon Hamilton, now dead, as "possible contributors" to the profile.
Mr Sinclair blames Mr Hamilton for the murders.
The teenagers were last seen alive at the World's End pub on 15 October 1977.
Ms Eadie's body was found the following afternoon at Gosford Bay, Aberlady, while Ms Scott's body was discovered a few hours later in a wheat field near Haddington.
Mr Sinclair has submitted three special defences of incrimination - blaming his late brother-in-law Gordon Hamilton; one of alibi - saying he was fishing on the banks of the Firth of Forth near Cockenzie power station at the time; and that the two girls consented to sexual intercourse.
Mr Sinclair is alleged to have gagged the girls, bound their wrists and tied a ligature around their necks.
He denies inflicting blunt force injuries on Ms Eadie by repeatedly punching and kicking her on the body and biting her.
He also denies forcing Ms Scott to walk barefoot into a field, ripping the strap from her handbag, repeatedly punching and kicking her on the head and body and stamping on her head.
And he denies stealing clothing, footwear, jewellery and other personal effects from the teenagers in an attempt to pervert the course of justice.
The trial continues.