Convicted sex killer Peter Tobin was jailed for a minimum of 30 years today for the "barbaric" murder of schoolgirl Vicky Hamilton.
The 62-year-old abducted, sexually assaulted and then killed the girl 17 years ago, before cutting up her body and burying it in his garden.
Tobin is already serving a life sentence for raping and murdering Polish student Angelika Kluk and hiding her body in a Glasgow church in 2006.
He was found guilty after a month-long trial at the High Court in Dundee.
Vicky's father Michael shouted "rot in hell" as Tobin was given a life sentence and told he would be 92 years old before he would be considered for release.
Judge Lord Emslie told the killer today: "Abducting and killing a child on her way home from a happy weekend with her sister and then desecrating her body must rank among the most evil and horrific acts that any human being could commit."
The judge continued: "By the verdict of the jury, you stand convicted of the truly evil abduction and murder of a vulnerable young girl in 1991 and thereafter you attempted to defeat the ends of justice in various ways over an extended period.
"Once again, you have shown yourself to be unfit to live in a decent society."
The judge continued: "I note that Mr Findlay, your senior counsel, has advanced no mitigating features on your behalf today.
"But any mitigating features would in any event have paled into insignificance by comparison with the enormity of your serial offending."
There were cries of "yes" and sobbing from the public gallery as Lord Emslie fixed the minimum sentence of 30 years.
As Tobin was led from the dock, someone shouted: "You'll die in jail."
During the trial, prosecutor Frank Mulholland QC, Scotland's solicitor-general, described Vicky's murder as "a barbaric act" and an "atrocity".
The 21-day trial heard that Vicky's remains were unearthed by police in a shallow grave in the back garden of Tobin's former home at 50 Irvine Drive, Margate, Kent, in November last year.
Her bisected body - badly decomposed by that stage - had been wrapped in layers of plastic bin bags "like a Russian doll" and dumped 3ft beneath the surface, under a layer of concrete.
The discovery came after the schoolgirl's family endured a 17-year nightmare, forced to wonder every day what had happened to their daughter and sister.
Tobin abducted Vicky in Bathgate, West Lothian, on the snowy evening of 10 February 1991.
The schoolgirl, from Falkirk, was waiting for a bus in the town centre to take her home to her mother in Redding, near Falkirk, after visiting her sister Sharon in Livingston, West Lothian.
The 15-year-old was said to have been nervous about the journey as it was the first time she had ever visited her sister on her own.
Tobin preyed upon her nervousness and lured her to his home at 11 Robertson Avenue, Bathgate.
There, or somewhere else, he drugged her with the sedative Amitriptyline, strangled her, carried out a serious sex attack and murdered her.
Experts told the trial that bruising found on her body suggested she met a violent death.
Bruises on the 15-year-old's hand suggested she fought bravely for her life, despite being sedated.
The killer then set about covering his tracks by hiding Vicky's body and getting rid of some of her clothing and personal belongings.
He cut her body in two, wrapped it in a curtain and bin bags, and stashed the knife in the loft of Robertson Avenue.
Tobin left the schoolgirl's purse near Edinburgh's main railway and bus stations to fool police into thinking she had run away from home.
The following month, he moved to Margate, taking the schoolgirl's body with him in his van.
It was there, in his own back garden, that he buried Vicky's body, hundreds of miles away from her family.
Yet when police confronted Tobin with damning DNA evidence against him in July last year, he insisted he had never met Vicky and refused to help officers find her body.
Lord Emslie told Tobin he had been convicted as a result of his own mistakes.
He said: "This was a vulnerable teenager who needed help on her way home, but instead she fell into your clutches and you brought her short life to an end in a disgusting and degrading way.
"No one will ever know what fear and torment Vicky Hamilton went through before she died.
"But the agony you caused to her family was made infinitely worse by your calculating and entirely self-interested attempts to conceal and avoid detection for what you had done."
Lord Emslie added: "It is hard for me to convey the loathing and revulsion that ordinary people will feel for what you have done.
"You already have an appalling record of convictions for sexual and violent crimes and are currently serving a life sentence with a 21-year minimum period in custody for the rape and murder of a young Polish girl in 2006."