A convicted killer and paedophile has been found guilty of raping and murdering two teenage girls 37 years ago.

Christine Eadie and Helen Scott, both 17, were brutally killed after a night out at Edinburgh's World's End pub on October 15 1977, with their bodies discovered the following day in East Lothian. They had been bound and strangled with their own underwear.

Angus Sinclair, 69, was convicted today of the rape and murder of both girls after a trial at the High Court in Livingston lasting five weeks.

He was jailed for a minimum of 37 years for the murders. The sentence - which comes 37 years after he murdered the two teenagers - is the longest ever handed out by a Scottish court..

Sinclair, a serial rapist who has been in jail for more than 30 years, was accused of carrying out the attacks with his brother-in-law Gordon Hamilton, who died in 1996.

The jury of nine women and six men took less than two-and-a-half hours to convict Sinclair unanimously of both charges.

In reaching their verdict, jurors were unaware that Sinclair has already spent more than half of his life in prison.

He was just 16 when he strangled seven-year-old Catherine Reehill in Glasgow in 1961, later pleading guilty to a charge of culpable homicide and serving six years.

In 1982 he was convicted at the High Court in Edinburgh of a string of sex attacks on 11 young girls - including three rapes.

While still in prison, he was given a life sentence in 2001 for the murder of 17-year-old Mary Gallacher, who was raped and stabbed in Glasgow in 1978.

The case, which became known as the World's End murders, was for decades one of Scotland's highest-profile unsolved crimes.

The discovery of the girls' bodies on October 16 1977, dumped in remote locations around five miles apart from each other, conveyed the unimaginable horror they suffered at the end of their all-too-short lives.

Christine's naked body was found at around 2.25pm that day at Gosford Bay, Aberlady. She had a ligature around her neck, her mouth was gagged with a pair of pants and her wrists had been tied behind her back.

She had been punched and kicked on her head and body, bitten, raped, bound and strangled.

Helen's partially-clothed body, discovered at around 6pm, had been dumped in a wheat field at the Huntington to Coates road, near Haddington.

Her hands were also tied behind her back and a ligature made from a belt and a pair of tights had been used around her neck.

Raped, bound and throttled, she too had been punched and kicked, and her head had been stamped on.

She might have been forced to walk barefoot into the field where she was found dead.

Days into the trial, the jury of nine women and six men would return to the isolated spots where the girls' bodies had been left, 37 years on from the brutal killings.

The court was told about the "terrible and life-changing" effect the murder had on Helen's family.

Her father told the court his wife Margaret, who died in 1989, was never the same again after their daughter's death.

Morain Scott, 84, said the death of his daughter marked the start of his wife's ill health, while he has lived with the loss for more than 30 years and has "just kept going".

After sentencing, Helen's brother Kevin Scott spoke outside court on behalf of the families of both girls.

Standing beside his father Morain and Christine's brother Hamilton Craig, he said: "We have waited 37 years for justice. Today that wait has ended and we finally have justice for Helen and Christine.
 
"It's been long and at times a very lonely battle but in our different ways we didn't give up and I would like to thank all those other people who didn't give up; our friends, the police again some no longer with us, the prosecutors, the forensic scientists and the public.
 
"Decades after their deaths, Helen and Christine's legacy is to have changed Scotland's justice system for the better, politicians came together for Helen and Christine and through the introduction of the double jeopardy amendment which will prevent other families suffering as we have."
Helen's father said of Sinclair: "I wouldn't call him an animal, because animals kill for food.
"He's just a beast if anything else and I'm quite sure in my own mind there could be other crimes against him."
In the words of the prosecutor Lord Advocate Frank Mulholland, as the girls begged to be freed, Sinclair and Hamilton ended their lives "like something that was wiped off a shoe".
Mr Mulholland thanked all of those who had helped bring Sinclair to justice, particularly "the thousands of police officers who have worked on the case over the years".
He took the unusual step of reading the names of all the senior investigating officers involved to the court, pointing out that many were now dead.
 
He said: "The police have never ceased in their endeavours to bring the girls' murderers to justice. Today that hard work, mirrored by that of the many experts who have given evidence in this case and who have contributed to this case, and in particular the forensic scientists, is now at an end.
 
"There are no words, no words whatsoever, that I can say to the court on behalf of the families of both girls that would do justice to the the loss felt by them for their beloved daughters and what happened to them and the 37 years they have had to wait for justice."
 
Speaking following the sentencing, Justice Secretary Kenny MacAskill said: "This case came to court after the Scottish Government brought forward the Double Jeopardy (Scotland) Act, which was unanimously passed by Parliament. Double jeopardy is a centuries old principle of Scots law which prevents a person being tried twice for the same offence, but in this day and age, there should be no escape from justice.
 
"We modernised the law, with safeguards, to make it fit for the 21st century. If new evidence emerges which shows the original ruling was fundamentally flawed, it should be possible to have a second trial. And trials which are tainted by threats or corruption should also be re-run.
"We have acted in the interests of Scottish justice, victims and their families and we hope this news brings some comfort to the families of the victims of these terrible crimes."
 
The father of Helen Scott branded his daughter's killer a "beast" and said the two girls could finally rest in peace after the jury's verdict.
Morain Scott, who gave evidence in the trial, said he was convinced that Sinclair may have other crimes to his name.
Speaking outside the court, the 84-year-old said: "I wouldn't call him an animal, because animals kill for food.

"He's just a beast if anything else and I'm quite sure in my own mind there could be other crimes against him."
Mr Scott said he would never forget the moment he was forced to identify his daughter's body.

He said: "It's justice for the girls, it's what I've always wanted and I promised my late wife I would fight to the end of my days.
"It will be closure I hope for some of my family but it will never be closure for me because I saw Helen that night when she was brought up from East Lothian.

"I'll never forget as long as I live, what I saw that day, what they had done to my beautiful daughter."
He said Sinclair's evidence in the witness box had been "ridiculous".
"To deny what he denied just was unbelievable. Nobody could believe that."
Asked if the girls could now rest in peace, he said: "Yes", adding: "The legacy is the double jeopardy Bill which must give hope to other families."

Helen's brother Kevin Scott joined his father outside the court to read a statement on behalf of both families, flanked by his daughter Aimee Helen Scott - who turns 17 on Sunday - and Christine's brother Hamilton Craig.
He said: "We have waited 37 years for justice. Today that wait has ended and we finally have justice for Helen and Christine.
"It's been long and at times a very lonely battle but, in our different ways we didn't give up and I would like to thank all those other people who didn't give up; our friends, the police again some no longer with us, the prosecutors, the forensic scientists and the public.

"Decades after their deaths Helen and Christine's legacy is to have changed Scotland's justice system for the better, politicians came together for Helen and Christine and through the introduction of the double jeopardy amendment which will prevent other families suffering as we have."

He gave the families' "heartfelt" thanks for the decades of "painstaking" work by police and prosecutors to bring about the verdict.
"Above all we would like to thank the people of Scotland we refused to let the memory of Helen and Christine fade. It was by keeping their memories alive over the last 37 years that we have finally achieved the justice they deserve.

"To everyone who has been involved in this case, I know this sad and long journey has touched your hearts and from the bottom of all our hearts we thank you for your tenacious passion, your determination and for being so thoughtful and so caring."