The man who murdered Irish vet Catherine Gowing has been jailed for life and will serve a minimum 37 years.
Ms Gowing's body has never been fully recovered, although remains were found at two rural locations near her home in Flintshire, North Wales, and near Chester.
Clive Sharp, 47, of no fixed address, pleaded guilty to her murder at Mold Crown Court last month.
Today Mr Justice Griffith Williams ordered that he serve a minimum 37 years behind bars before he can be considered for parole.
The vet's disappearance in Flintshire last October sparked North Wales Police's largest ever search operation.
Passing sentence, Mr Justice Griffith Williams told Sharp: "This is a horrific, cold hearted murder, carried out to gratify your perverted sexual desires."
Sharp, dressed in grey jogging bottoms and a grey jumper, made no reaction but the victim's sister, Emma, sat in the public gallery just yards from the dock, did not take her eyes off the defendant throughout the 50 minute hearing.
The court heard Sharp had a string of previous convictions for sexual offences, beginning when he was just 16 and he harboured perverted sexual fantasies involving the gagging, raping and murdering of women - which he acted out on Miss Gowing.
And just hours before the murder he left another woman tied to a bed after she refused to take part in perverted sexual acts, Mold Crown Court heard.
The judge said Sharp broke into Miss Gowing's house in the middle of the night, tied her to the bed and kept her prisoner while she was raped repeatedly and sexually abused.
Then, in a further "callous act", he cut up her body and disposed of her in various places along the River Dee.
Mr Justice Griffith Williams said: "You are, on any view, a very serious danger to women."
The defendant has previously been jailed twice for rape and sexual assaults.
He told probation and prison authorities of his long-standing fantasies involving imprisoning, raping and murdering women.
Emma Gowing told the court in a victim impact statement: "My sister was a vibrant, wonderful woman, who lived life fully, with love, compassion, fun, adventure and joy.
"Our lives will never be the same.
"That man has caused my family unimaginable pain, suffering and grief and the recurring nightmare of what he did to her before she died."