DNA clue offers new hope for families of girls killed in 1977 'World's End' murders

For more than a quarter of a century the families of two teenage girls raped and strangled after a night out have waited patiently for science to catch up with their killer.

Helen Scott and Christine Eadie, both aged 17, were victims of the "World's End" murders, referring to the pub on the Royal Mile in Edinburgh where they were last seen alive in 1977.

Helen's father, Morain Scott, lost his wife to cancer in 1989, a tragedy he blamed on the continuing stress and grief caused by their daughter's death. But the 72-year-old retired BT engineer has never given up hope that the murders would be solved in his lifetime.

Now at last there are signs that his patience might be rewarded. New technology has enabled police to find a DNA sample from the scene. And next week, Lothian and Borders Police will begin gathering samples for comparison from more than 200 people.

The breakthrough has come with a new technique enabling scientists to obtain DNA evidence from items the size of a single skin cell. As a result, police have pinpointed the DNA of one unidentified man who was involved in both killings. Police suspect another person was involved because of the way both girls had their hands tied behind their backs when they were discovered. Detectives have a list of people whose DNA closely resembles that in their sample.

Mr Scott said: "The police remain confident that we will identify who killed my daughter. I have always believed there are a number of people out there who never contacted the police at the time the girls were killed, either because they were afraid or because they didn't think what they had seen was important."

Detective Inspector Allan Jones, who is leading the investigation, said: "We currently hold a DNA profile, linked to both girls, of an unknown man whom we believe may have a direct connection to these murders."

After research using a national database of DNA taken from criminals, police are hoping to identify relatives of the killer, or the killer himself. Det Insp Jones said: "We are now in a position to approach 200 targeted individuals and ask them to provide a DNA mouth swab. This is being requested on a voluntary basis and we are dependent on the goodwill of those approached to take part and help us eliminate them and potentially their relatives from this inquiry. Unlike conventional methods of DNA screening, which focus on eliminating people identified through suspicion or circumstantial evidence, this approach targets people whose DNA profile shows a high level of similarities to our profile, opening up the possibility that they may be related through family."

Police havelaunched an internet appeal for information and designed an interactive web page - www.lbp.police.uk - to publicise the case and encourage anyone with information to come forward. It is the first time such an approach has been used by any police force. Detectives fear that after such a long time many potential witnesses might have moved away from the area and could now be living anywhere in the world.

On Wednesday night detectives renewed their plea for help on the BBC's Crimewatch programme. Police said they had received more than 100 offers of information, including from a woman who had known the victims but had never come forward.

Helen and Christine were last seen alive on Saturday 15 October 1977 when they met two other girlfriends for a tour of various pubs which culminated at the World's End.

While there, they engaged in conversation with two men. When their friends left for a party, Helen and Christine chose to stay and talk to the men. Apart from a brief sighting of them with the two men shortly afterwards, they were never seen alive again.