Police investigating the deaths of two teenagers in 1977 hunted for a suspect's DNA in his ex-girlfriend's home 30 years later, a court has heard.
Helen Scott and Christine Eadie went missing in 1977
Detectives probing the deaths of Christine Eadie, 17, and Helen Scott, 17, went to a flat once decorated by Gordon Hamilton in 2005.
The teenagers' bodies were found after a night at Edinburgh's World's End pub.
Angus Sinclair, 62, denies acting with Gordon Hamilton, who has since died, in their rape and murder.
Witness Lorna Carmichael, 51, told jurors at the High Court in Edinburgh how she was contacted by police who wanted to look round her former flat in Dennistoun, Glasgow, in 2005.
The housekeeping manager lived in the property from 1994 to 1998, during which time she was in a relationship with Mr Hamilton, she said.
Mr Hamilton carried out extensive refurbishment of the flat, including wallpapering and relining the ceiling of a bedroom.
The girls were last seen alive at the World's End pub
Another witness, Derek Carroll, an identification officer with Strathclyde Police at the time, told how he removed two pieces of coving or cornicing and a section of ceiling wallpaper from the room.
Defence counsel Edgar Prais asked Mr Carroll: "What was it all about?"
The witness replied: "I knew it was in connection with the World's End murders."
Mr Carroll added: "I knew they (the police) were hoping to get some DNA."
The court heard earlier how the DNA evidence obtained from the 1977 swabs had been passed through "umpteen" laboratories in the 30 years since the deaths of the two girls.
Forensic scientist Susan Ure agreed that the samples had been tested by many scientists across the UK.
Mr Prais asked the Tayside-based scientist: "It's been through umpteen different laboratories and through the hands of umpteen different scientists, hasn't it?"
Ms Ure agreed.
The trial continues.