A sexual predator who murdered a “trusting and friendly” mother in her home more than 36 years ago has been jailed for life after being snared through a DNA breakthrough.

Convicted rapist Graham McGill 59, was an inmate at HMP Edinburgh on temporary release when he strangled Mary McLaughlin, 58, in Partick, Glasgow in 1984.

The mother-of-11 had enjoyed a night out drinking and playing dominoes at different bars on Wednesday September 26 of that year and was last seen at about 10.45pm heading to a chip shop on her way home.

McGill strangled her with her own dressing gown cord and her body was found days later by one of her sons.

McGill was convicted following a trial at the High Court in Glasgow  last month.

Ms McLaughlin’s death sparked a major police investigation and spawned dozens of lines of inquiry, but the cold case remained unsolved until modern DNA techniques placed McGill in her flat with a greater than billion-to-one likelihood, the trial heard.

McGill’s ex-wife, Suzanne Russell, also told jurors that in 1988, he had confessed to murdering a woman because he “just wanted to know what it felt like”.

He was sentenced at the High Court in Aberdeen on Tuesday to life imprisonment and will have to spend 14 years behind bars before any possible release on licence.

Sentencing him, Judge Lord Burns said: “36 years after the death of Mary McLaughlin, you have been convicted of her murder. She was 58 when she died and you were 22. You are now 59.

“Her family has had to wait all that time in order to discover who was responsible for that act knowing that whoever did it was probably at large in the community.

“They had never given up the hope that some day they would find out what had happened to her. They have been deprived of her love and companionship.

“It is due to the perseverance of police authorities and, in particular, the forensic biologists, that your guilt could be demonstrated.

“The evidence showed that your chance encounter with Mary McLaughlin that night allowed you to take advantage of a vulnerable and lonely woman who was probably intoxicated.

“The attack took place within her own home to which she may have invited you. She was wholly unable to defend herself against any attack from someone like you.

“You proceeded to strangle her with a cord until she was dead. You then left her in her house.

“From the evidence of Suzanne Russell, to which I can have regard, it may be that you made a calculated decision to kill this woman.

“She was eventually found by one of her sons. You continue to deny any responsibility for your actions. You therefore show no remorse for this murder.”

Procurator Fiscal for Homicide and Major Crime, David Green, said: “This was a challenging investigation requiring complex and thorough work by specialist prosecutors.

“Under their direction, experts in forensic science saw an opportunity to use modern DNA techniques to analyse evidence from the scene that had been preserved by the original investigating officers before such techniques were available to them.  This foresight ultimately led to Graham McGill’s conviction.

“Unresolved homicides are never closed, and the Crown is committed to working with police to bring these cases to court wherever possible.

“Our thoughts remain with Mary’s family, and I hope the sentence imposed today goes some way towards providing resolution for them.”

Police Scotland Detective Superintendent Suzanne Chow echoed his comments, saying: “Mary’s family has waited a long time for justice and I hope today’s verdict provides some form of resolution for them.

“It is fitting to know that despite the passage of time, justice has finally been served.”

She added: “Despite crimes occurring years ago, there is always hope of solving them one day. They are never forgotten.”