A killer who tried to emulate Jack the Ripper was today jailed for life for the murder of two young mothers at the start of what may have become a killing spree.
Loner Derek Brown was told he must serve a minimum term of 30 years in prison for killing DVD seller Xiao Mei Guo and prostitute Bonnie Barrett.
Brown, 48, butchered the women in his flat before disposing of their bodies, which have never been found.
An Old Bailey jury found him guilty of both murders after deliberating for less than three hours on Friday.
After the verdicts, relatives of both victims made emotional appeals for the killer to tell them what he had done with their remains.
Police believe he may have killed before and are combing crime files across the country to see if his details match up with other cases.
Brown, who craved notoriety, picked up Mrs Guo and Miss Barrett in the same Whitechapel area of east London stalked by the Ripper more than a century ago.
Already a serial sex attacker, detectives believe he would have become a serial killer if he had not been stopped.
Inquiries have since revealed the convicted rapist was also a suspect in a third "historic" murder hunt outside London.
Brown, a father of seven, has in addition been identified by victims in five other rapes over two decades and is suspected of carrying out further sex attacks.
Judge Martin Stephens said Brown had been convicted on "overwhelming" evidence and told him: "You have shown not a sliver of remorse.
"You murdered two women. Both were vulnerable, plying their trade on the streets, in each case falling into your hands precisely because of their availability and their lack of protection.
"What you did to each of those women before you killed them we can only speculate about. How you killed them we cannot know.
"What we do know is you disposed of their bodies with frightening efficiency so that not a trace of either woman has been found.
"Whilst there is no direct evidence of how you disposed of their bodies, there is clear circumstantial evidence that you dismembered them or disposed of them using equipment and materials you bought for the purpose.
"The only person who could prove this not to be true would be you, if you ever chose to tell the police where their bodies or remains could be found.
"The anguish of both victims' families is exacerbated, made much worse by their inability to lay each lady to rest."
He said Brown had taken a "devious and cowardly course" at the trial by refusing to be cross-examined after giving his "lying account" to the jury.
He said he had considered a whole-life term and said while there "must have been a degree of pre-meditation", the features necessary for such a sentence were not "fully made out".
The successful prosecution of a double murder, despite no bodies having been found, was believed to be legally unprecedented.
Meanwhile, a nationwide review is being launched to establish whether Brown, originally from Preston, Lancs, is linked to any further unsolved crimes.
The bodies of Mrs Guo and Miss Barrett have never been found, despite 800 hours of police searches and a trawl of the Thames by divers.
Brown might have disposed of them in the river or by dumping them in hospital bins or an industrial compactor at his workplace.
Jurors heard 65 separate traces of the women's blood were found spattered around the floors, walls and ceiling of his flat in Rotherhithe, south east London.
Mrs Guo, a 29-year-old illegal immigrant, was last seen, with Brown, on CCTV images taken outside Whitechapel Tube station on 29 August last year.
Miss Barrett, 24, a crack addict who had previously been paid for sex by Brown, disappeared just half a mile away on 18 September.
Brian Altman QC, prosecuting, said: "Both lived on the edge of society and both were soft targets for the killer, who thought that neither woman would be missed."
Police discovered a receipt at Brown's flat showing he had spent hundreds of pounds on items including a bow saw, heavy duty gloves, cleaning materials and rubble sacks.
They also found a library book, Killers - The Most Barbaric Murderers Of Our Time, which included chapters on the Yorkshire Ripper, Myra Hindley, and the Boston Strangler.
Weeks before the women went missing, Brown ominously warned a female friend: "You will hear of me. I am going to be famous."
Detective Chief Inspector Mark Kandiah, who led the investigation, said: "He is clearly a very evil man. In my opinion, he was not going to stop."
Police think Brown was motivated by sex and a desire to become notorious like Jack the Ripper, who murdered prostitutes in the 19th century.
After last week's verdicts, Miss Barrett's mother Jackie Summerford appealed directly to Brown, saying: "I am asking you, Derek Brown, to tell me where my daughter is so we can lay her to rest."
Mrs Guo's husband Jin Hua Guo said: "We want her body so my children and I can say goodbye. This man has deprived me of that to conceal his own guilt."