Eight years after the Dando murder, Barry George is told his conviction was unsafe

Barry George had his conviction for murdering the television presenter Jill Dando quashed yesterday after the court of appeal concluded that fresh scientific evidence meant that there was "no certainty" that the jury at his original trial would have convicted him. The court ruled that the original verdict was unsafe.

George, 47, who remained impassive when the lord chief justice, Lord Phillips, announced the court's decision, will face a retrial next year. His legal team is considering whether to apply for bail, as the trial is unlikely to take place before the end of next summer.

"I just want to say thank you to the judges in there," said George's sister, Michelle Diskin, after the decision. "They were very fair and they really did look at the evidence. This is just one step along the way. We do not really feel that we have a victory. We do not have Barry. He has not got his freedom yet and it has been an absolute nightmare journey so far." Diskin, who has campaigned on behalf of her brother since his conviction in 2001, said they were "back at first base now".

George's solicitor, Jeremy Moore, also welcomed the decision. "We are very pleased with the outcome," he said. "This is only the latest hurdle in what has been a very long road and we now look forward very much to preparing for the trial. Barry is also very pleased."

George, who had a psychologist beside him in the dock to explain what was happening, because he suffers from learning difficulties, was remanded in custody.

The judge, who sat with Lord Justice Leveson and Mr Justice Simon, said the prosecution had relied on four categories of evidence at the original trial in 2001. One category had been identification evidence, which placed George near the scene on two occasions on the day of the murder; the second ground was "repeated lies" told by George in police interviews; the third category was an alleged attempt to create a false alibi; and the fourth was a tiny particle of firearms discharge residue (FDR) found in his overcoat about a year after the murder.

Last week, the appeal court heard from expert witnesses from the Forensic Science Service that "it was, in fact, no more likely that the particle had come from a gun fired by Barry George than that it had come from some other source".

The lord chief justice told a packed court that "if this evidence had been given to the jury at the trial, there is no certainty that they would have found Barry George guilty. For this reason his conviction had to be quashed."

In the fuller, written judgement, the court said: "It is impossible to know what weight, if any, the jury attached to the FDR evidence. It is equally impossible to know what verdict they would have reached had they been told, as we were told ... that it is just as likely that the single particle of FDR came from some extraneous source as it was that it came from a gun fired by the appellant. The verdict is unsafe."

Orlando Pownall QC, for the crown, told the court that they would seek a retrial.

William Clegg QC, for George, asked the court to issue instructions to the media on the future coverage of the controversial case. At the start of the three-day appeal last week, the lord chief justice said that correspondence about the case had been sent to him and his fellow-judges which was inappropriate. He also said that the court would consider the "propriety" of recent television programmes about the case, one of which carried interviews with two jurors from George's original trial.

Yesterday Clegg said that the letter sent to the judges prior to the appeal, which "contained a number of material inaccuracies", had also been published in a national newspaper. This is believed to be a reference to an open letter from Dando's former colleague and friend Nick Ross, which was published in the Daily Mail two days before the appeal started. "There should be no further repetition of the details of the case," said Clegg. He said much of the coverage in the media leading up to the appeal had been "inaccurate."

The lord chief justice said that he would emphasise to the media their potential liabilities under the contempt of court rules which now come into force and which will remain active until the conclusion of the retrial.

Dando, co-presenter of BBC's Crimewatch UK programme, was shot dead on the doorstep of her home in Fulham, south-west London, in April 1999. George, who lived near her home, was arrested for her murder a year later and convicted and jailed for life at the Old Bailey in 2001. His first appeal, in 2002, was unsuccessful, but the matter was re-examined by the Criminal Cases Review Commission, which referred it back to the court of appeal.

Clegg told the court last week that the jury were given the impression that the particle of FDR was "crucial" to the case, whereas they should have been told that it was "neutral" or "inconclusive". At the appeal, Pownall argued that the particle evidence was only one part of a "compelling" prosecution case against George and it had been challenged heavily at the original trial.