William Dunlop was jailed for life yesterday for the double jeopardy murder of young mother Julie Hogg.
Dunlop was told he would serve a minimum term of 17 years for the 1989 killing of the 22-year-old pizza delivery woman.
It was the end of a 15-year battle by Ms Hogg's mother, Ann Ming, aged 60, to have the law changed and get justice.
The case made legal history last month when Dunlop, 43, pleaded guilty to murder at the Old Bailey.
He was the first person charged twice with the same offence after the 800-year-old double jeopardy laws were changed.
Miss Hogg's disappearance in November 1989 was initially treated as a missing person inquiry until she was found 80 days later.
Mrs Ming found her decomposing and partially mutilated body behind a bath panel.
Dunlop was formally cleared of murder after two juries failed to reach verdicts.
But he was jailed for another assault and confessed in 1999 to a prison officer, boasting that there was nothing anyone could do about it.
The following year, he was jailed for six years for perjury - and charged with the murder again this year after the law was changed.
Mrs Ming and her husband, Charlie, 81, travelled to London from the family's home in Billingham, Teesside, to see Dunlop jailed.
She sobbed as prosecutor Andrew Robertson, QC, described Ms Hogg's injuries.
He said: "The overwhelming inference is that the deceased rejected him and was subjected to a violent sexual assault."
Dunlop had said he strangled Ms Hogg after she taunted him about a black eye, but this was not accepted by the prosecution.
Mr Robertson had told the court: "Now the law has changed, in large part due to the long and persistent campaign by Mr and Mrs Ming who felt they and their daughter were being denied justice."
An impact statement from Mrs Ming was read to the judge, Mr Calvert-Smith.
In it, she said the shock and after-effects of finding the body after police had failed to discover it during a search "verges on the indescribable".
"To this day, I can still smell the putrefied smell which was our daughter," she said.
"As a family, we are damaged beyond repair and will never be the same again as Julie will never return home.
"The love we feel for Julie means it is we who are serving the life sentence."
Ms Hogg, who was separated from her husband, had a son, Kevin, who was three when she was murdered.
He was not in court, but his statement described how his grandparents had tried to shield him from the truth by telling him his mother had died in the bath.
He only discovered what happened when he was 13 and was taunted by other children at school.
Timothy Owen QC, defending, said Dunlop had confessed through remorse.