Police believe up to another 100 women were also attacked by Victor Willoughby, 30, but have not reported the crimes. Yesterday they appealed for them to come forward.
The Old Bailey was told that Willoughby began targeting his victims in London two months after he was released from jail for a previous sex attack. He showed no emotion as the jury convicted him of four rapes, buggery, three indecent assaults, false imprisonment, and robbery.
The eight women, aged between 16 and 47, were subjected to sexual assaults around Willesden, north-west London, over a 12-month period. Willoughby, of Tottenham, north London, stalked night buses and scoured streets in his search for victims. All the women were on their way home after a night out.
A DNA sample was used to convict the rapist, who had denied all the charges.
The Common Sergeant of London, Judge Neil Denison, said the attacks "were all of the most appalling ferocity".
"The protection of the community and particularly of women requires that I pass an indeterminate sentence."
Detective Superintendent Duncan MacRae, who led the investigation, speaking after the trial, said: "Our inquiry tells us there are many more victims out there. Certainly he is the most prolific rapist to be caught using DNA. We are dealing with the tip of the iceberg ... I would not be surprised if over 100 rapes had been committed."
He said Willoughby was the most dangerous serial sex offender he had ever come across. The police yesterday appealed to women who had not yet reported attacks to contact their helpline on 0181 733 3842.
Willoughby was trapped by a police surveillance operation, codenamed Pandora, in which plain clothes officers followed night buses. In October last year the rapist, who always wore a hood or mask, was seen following a night bus in a stolen car and chased by police. He escaped but one of the officers recognised him.
DNA tests on a sample of his hair matched semen found after several of the attacks.
Willoughby had previously been sentenced to eight years in 1986 for attempting to rape a woman walking home from a night bus. On his release in 1992, he wounded a man in a street attack and was sent back to prison for 12 months.
Released in August 1993, he began stalking and attacking his current victims within weeks. Two were in court yesterday to see him sentenced.
In one attack he pretended he was a minicab driver and then raped the woman in the car. Another he knocked out before driving her to a garage where he raped her.
In some attacks he hid behind bushes and pounced on his victims from behind, dragging them into alleyways and, on one occasion, into a churchyard.
He received life sentences for each of the rapes and the buggery. He was jailed for 10 years for the indecent assaults, 10 years for false imprisonment, eight years for robbery and attempted robbery and 12 months for dangerous driving - all to run concurrently.
Two of his victims - both students - joined the police appeal for other women attacked by Willoughby to come forward.
One victim, aged 22, said the attack had changed her life and made her so angry she was determined to go through with the court case. "It has made me a lot more nervous about going out. It has made me rethink everything I do - like walking down the street, going out at night, everything," she said.Reuse content