The man serving life for the murder of schoolgirl Milly Dowler has made a fresh confession over the deaths of a mother and daughter, his lawyer said.
Levi Bellfield made a statement last year in which he admitted killing Lin Russell and her daughter Megan in Kent in 1996, but he later retracted it.
His lawyer said he had now made a fresh signed statement, saying he “needs to take responsibility”.
Michael Stone was jailed in 2001 for life for the murders.
Stone has always protested his innocence over the attacks, and of trying to murder Megan’s sister Josie.
In 2017 his legal team said they had seen evidence of a full confession by Bellfield, something he denied at the time.
Theresa Clark, Bellfield’s solicitor, said the new confession was more detailed, handwritten and signed by him.
Ms Clark said Bellfield’s latest confession had been made after he engaged with prison psychologists.
“At the end of the day, the instruction from my client is clear,” she told the BBC. “He’s adamant that he did it.
“My client says ‘I did it, I need to take responsibility for what I’ve done’.”
Ms Clark said Bellfield wanted relatives of those who were killed to have “resolution”.
“He’s not doing this because he’s friendly with Stone, it’s more for the families and Josie Russell,” she added.
She said the confession had been passed to the Criminal Cases Review Commission.
The CCRC has been approached for comment by the BBC.
Stone’s solicitor, Paul Bacon, told the BBC the police now needed to “respond and investigate these matters afresh to affect closure for these families”.
Lin Russell and her daughters Megan, then six, and Josie, nine, were attacked as they walked along a country lane in Chillenden, before being bound, blindfolded and bludgeoned with a claw hammer.
On the day of the murders, Dr Shaun Russell was told that he had lost his whole family. It was only when an officer at the scene noticed Josie move they realised she had survived the attack.
Stone was first found guilty of two counts of murder and one of attempted murder in 1998 and again in 2001, after the Court of Appeal quashed his conviction due to doubts over a prosecution witness.
Bellfield is currently serving a whole life sentence for the murder of 13-year-old Milly, who went missing from Walton-on-Thames, Surrey, in 2002.
He has also been convicted of murdering Marsha McDonnell and Amelie Delagrange, and of the attempted murder of Kate Sheedy, and will never be considered for parole.
Det Chief Supt Lucy Morris, from the Kent and Essex Serious Crime Directorate, said: “Following two trials at which he was found guilty by a jury on both occasions, and an appeal to the High Court, Michael Stone remains convicted of the murders of Lin and Megan Russell and the attempted murder of Josie Russell in 1996.
“Stone made an application to apply for a Judicial Review in respect of his conviction in September 2012. The Honourable Mr Justice Blake ordered that permission for the application should be refused.
“The Criminal Cases Review Commission commenced an extensive re-examination of the murder investigation in 2017 and has had access to all forensic evidence, documentation and exhibits from the original investigation, the review by Hampshire Police, details of the two Crown Court trials and appeals to the High Court.”
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