Killer Steven Beards will serve at least 33 years in prison in England after luring a student with learning difficulties to his wife's bungalow then drugging, raping and murdering her.
Susan Whiting was attacked with a blunt object and discovered with a fractured skull, her wrists bound and a plastic bag over her head.
The 20-year-old had been invited to have dinner and spend the night at a property in Bloxwich, Walsall, when she was brutally attacked in August last year.
Her body was found semi-naked and wrapped in a shower curtain hidden underneath a bed on August 17, with tests showing traces of a "sedating hypnotic drug" named Zoplicone in her system.
Beards, 34, was sentenced to life imprisonment after being found guilty of murder and rape at Leicester Crown Court.
His wife, Julie Beards, 36, was convicted of manslaughter and will be sentenced at a later date.
Speaking after the case, the victim's mother Maureen said: "From the moment Susan was reported missing our lives have been turned upside down.
"Susan's death is such a tremendous loss to our family.
"She was just 20 years old, an easy-going, loving young lady, enjoying her life. I know she was loved and will be missed by so many people.
"We would like to thank family, friends, the local community and all the professionals who have supported us over the past months. We will honour her life by the way we continue to live ours."
Detective Superintendent Mark Payne, who heads West Midlands Police's homicide team, said the couple had never explained the motive for the attack.
He said: "Susan Whiting was a vulnerable young woman who lost her life at the hands of this pair, who betrayed her trust.
"The two have never given a reason why Susan was killed, but we believe the attack was pre-planned and sexually motivated.
"Susan had gone to the home of someone she thought she could trust. I welcome the fact both have been convicted and, while this cannot bring Susan back, I hope this goes some way to comforting her devastated family and friends."