Attempts to uncover previous crimes committed by serial killer and rapist Peter Tobin have been boosted by a television appeal.
Detectives investigating Tobin, 64, received fresh information following a plea made on Wednesday night's Crimewatch programme.
Tobin is serving three life sentences for the murders of schoolgirl Vicky Hamilton, 15, Dinah McNicol, 18, and 23-year-old Angelika Kluk.
It is feared he may have committed many other violent offences.
Seven rape victims were identified following a previous appeal in July.
Last night officers revealed they are hunting for a married couple who acted as witnesses to Tobin's first marriage in Brighton in 1969 to Margaret Robertson, who was 18 at the time.
They also want to speak to another man called Paul.
Detective Superintendent David Swindle from Strathclyde Police, who is leading the UK-wide investigation, said: "We are delighted with the response we have received from the public following last night's Crimewatch appeal.
"We have received a lot of information regarding the specific appeal we made regarding the couple who were the official witnesses to Tobin's first marriage and the man, named Paul, who Tobin was very friendly with in Brighton during the mid-1980s.
"At this stage, we have yet to identify these three individuals, but we are currently in the process of researching all the information in the hope that it will provide us with more detail regarding the three people we appealed for."
Tobin was 22 when he first married. The couple who are the subject of the appeal, a Mr and Mrs Hardy, lived in St Michael's Place in Brighton at the time.
Paul, whose surname is possibly Maguire, was a good friend of Tobin's and was linked to the biker scene. He is said to have spoken about the French Foreign Legion.
Police set up Operation Anagram after the rape and murder of Polish student Ms Kluk at a Glasgow church in 2006.
They followed a trail to the garden of Tobin's former home in Margate, Kent, where they unearthed the bodies of Ms McNicol and Vicky two years later.
By piecing together information on his whereabouts over the years, police hope to establish whether he can be linked to, or ruled out of, other crimes.