Black cab rapist John Worboys should "never have been considered to be released", his victims' lawyer said.
Worboys, who is now known as John Radford, was jailed in 2009 for rape and sexual assaults on 12 women in London. He may have attacked up to 100.
In January, the Parole Board said he would be freed after serving 10 years, but the High Court overturned this decision following a challenge.
A different Parole Board ruled on Monday that he must stay in prison.
Lawyer Kim Harrison told BBC Breakfast the legal decision was "bittersweet" for victims as they felt they had been ignored since January.
But she added the initial reaction to Monday's ruling was one of immense relief.
"[Worboys] still believes rape is acceptable. He still wants to control women, he still has issues around sexual fantasies and drug and alcohol issues. This man should never have been considered to have been released, it was plainly the wrong decision that was made before," Ms Harrison said.
She said the 61-year-old's victims still felt astonished that a parole board could reach two completely separate and opposite decisions in the space of 12 months.
"Judges in the High Court ruling said they had taken into account too much of what Worboys was saying and were manipulated by him, which is exactly what we were saying at the time.
"In January we were saying this man is manipulative, this man is dangerous, this man is gaming the parole board, and actually that turned out to be true."
Worboys was convicted of 19 offences including one count of rape, five sexual assaults, one attempted assault and 12 drugging charges.
As well as being ordered to serve at least eight years, Worboys was given an indeterminate sentence, meaning he could be kept in prison as for as long as he was deemed to remain a danger to the public.
Police believe Worboys may have carried out more than 100 rapes and sexual assaults on women in London between 2002 and 2008.