Barry George was convicted of the murder in July 2001
Last summer the Criminal Cases Review Commission (CCRC) referred Barry George's conviction back to the Court of Appeal because they had uncovered new evidence that undermines the reliability of the forensic evidence presented to the jury.
In their statement of reasons, setting out their decision, they said:
"New evidence calls into question the firearms discharge evidence at trial and the significance apparently attached to that evidence."
During the original trial, Mr Robin Keeley a forensic expert who worked for the Forensic Science Service, told the jury that he'd found a single microscopic particle of firearm's residue on the inside of a coat belonging to Barry George.
The coat was seized by the police during a search of Mr George's flat in April 2000 - a year after Jill Dando's murder.
Mr Keeley said the particle was "similar" and "consistent" with other particles found on Jill Dando's hair and coat. The prosecution took this and told the jury it was "compelling" and linked Mr George to the crime.
As part of Panorama's investigation we took a bold and unusual step by interviewing two members of the trial jury about their interpretation of this evidence.
Juror Janet Herbert doubted the particle linked George to the murder
Jury member Janet Herbert said:
"I think it was the strongest piece of evidence the police had against Mr George. It came over that this was definitely the particle that came from the gun that killed Miss Dando and the particle was in his coat."
And the foreman of the jury, who wishes to remain anonymous, told us:
"I think it was one of the foundations of the prosecution case. I think without that the prosecution case would have failed... it was put across at the trial that it linked him to the crime."
Last year Panorama raised concerns about the reliability of the forensic evidence which pressed the CCRC to carry out further investigations as part of their review into the safety of the conviction.
They uncovered information that a senior scientist at the Forensic Science Service, had raised concerns about the weight the media had attached to Mr Keeley's evidence over the particle.
In his report to the CCRC, the senior scientist said he'd felt "a vague unease" about significance being attached to the finding, so arranged to meet with Mr Keeley.
The meeting took place in November 2001, four months after Barry George was convicted of Jill Dando's murder.
Mr Keeley had agreed "the weight of evidence associated with the finding of a single particle was zero". Although both men were concerned as to whether the court had been left with the right impression they did not notify the defence or prosecution and instead, "agreed to do nothing".
Panorama reporter Raphael Rowe spoke to the foreman of the jury
The CCRC concluded in their report:
"The commission finds difficulty interpreting Mr Keeley's evidence at trial as having conveyed the message that the finding of the single particle of FDR was inconclusive, neutral or of no evidential value."
The CCRC go on to say that on this basis the particle evidence should never have been admitted.
Janet Herbert told us she had never accepted the prosecution claims that a single particle proved a link between Barry George and the murder of Jill Dando.
The foreman said that if he'd known the forensic evidence was inconclusive and that:
"If the trial were to go ahead again tomorrow in exactly the same way then the verdict would be very different."
We don't know whether the views of Janet Herbert and the 'foreman' reflect the views of the remaining jury members, who we did not interview, and the Court of Appeal will have to consider what, if any, impact the CCRC findings has on the safety of Barry George's conviction.
There are various options open to the Court of Appeal when they consider Barry George's conviction next week: they could quash the guilty verdict and order his immediate release from prison; they could order a re-trial or they could rule that even without the forensic evidence, the jury reached the right verdict and Barry George will continue his life sentence for Jill Dando's murder.
Panorama: Jill Dando: The Jury's Out, BBC One 8.30pm, Monday 29 October 2007