The parents of Joanna Yeates have spoken of their regret that Vincent Tabak will not hang after he was found guilty of her murder.
Instead they hope the rest of his life would be "a living hell".
The killer was jailed for life after a jury took three days to find him guilty of throttling the 25-year-old.
It was revealed after the trial that Tabak was obsessed with images of women being strangled during sex. Jurors were not told how videos found on his laptops had chilling parallels with the way Miss Yeates died. His pornography depicted blonde women being throttled during sex or bundled into car boots. Two weeks before murdering the landscape architect, he paid for sex with a prostitute during a business trip to Los Angeles.
The judge said it would be inappropriate to include Tabak's previous sexual perversions in the trial. But despite being blocked from hearing of his depraved sex secrets, jurors found he was a liar who had been aroused during the attack.
Tabak, 33, showed no emotion as he was found guilty and then jailed for life after Mr Justice Field condemned him as "wicked".
Miss Yeates's parents David and Teresa - who were too distraught to attend court on Friday - said in a statement how they "regret that capital punishment is not a possible option". Her relatives added: "The best we can hope for him is that he spends the rest of his life incarcerated where his life is a living hell, being the recipient of all evils, deprivations and degradations that his situation can provide."
Tabak murdered his next-door neighbour before spinning a web of lies and deceit to cover his tracks. He strangled Miss Yeates in a violent confrontation at her flat in Clifton, Bristol, on December 17 last year.
He scoured the internet for clues to how he could get off the hook before and after her snow-covered body was found by dog walkers on Christmas Day.
Jailing him for life with a 20-year minimum term at Bristol Crown Court, Mr Justice Field attacked him for "a dreadful, evil act committed against a vulnerable unsuspecting young woman in her own home". He added: "That wicked act ended the life of a young woman who was entitled to expect a life of happiness and fulfilment."