Scotland Yard has been warned that a "cold case review" into Jill Dando's murder, in the wake of the acquittal of Barry George, is unlikely to solve the case.

A team of detectives – some of them possibly coming out of retirement for the special assignment – will run through the evidence afresh. The review could take months to complete and there was concern among Ms Dando's friends yesterday that it could be a fruitless task.

Her agent, Jon Roseman, said: "I don't think the police will find her killer now. It's too late for that. There's no new evidence, no new witnesses after eight years."

Officially, the Metropolitan Police is not discussing its next step, and a spokesman said yesterday: "We are considering the ramifications of the jury's verdict before we do anything else."

But detectives will order the cold case review, a standard strategy for reviving unsolved murder investigations.

Police sources said a review would typically concentrate on using new forensic techniques, although it is understood officers looked at many of the 3,700 exhibits ahead of Mr George's second murder trial and drew a blank. Blood stains found on some of his clothes turned out to be his own.

"It can be difficult with cold case reviews because the whos, wheres and whens in the witness statements aren't going to change," said one source. "If you haven't got any new forensics, it can be tricky to find new leads."

Mr George, 48, walked free from the Old Bailey on Friday after eight years in jail, whisked away to a hotel bar by his supporters for a celebratory cocktail. He was arrested just over a year after Ms Dando, 37, the presenter of Crimewatch, was shot dead on her doorstep in Fulham, west London on 26 April 1999.

"I don't want to spend any more time in any of Her Majesty's holiday camps," Mr George told the Sunday Mirror. "I won't follow women any more. I know it's wrong. I am never going to give anyone the chance to send me away again. I don't want people to always say: 'There's Barry George; he killed Jill Dando.' I want them to say: 'There's Barry George; he didn't kill Jill Dando.'"

Mr George's uncle, Michael Bourke, said: "It's not a celebration. Barry was locked away for eight years for something he didn't do." Mr Bourke's Irish MP, Willie O'Dea, who is also the country's Defence Minister, said: "I was struck by the fact there was a huge demand in the UK for somebody's head. The pressure on the police must have been enormous."

The pressure on the police is still enormous with the original investigation under scrutiny. Mr George was considered an oddball who posed wearing gas masks and holding a starting pistol, kept a collection of photographs of women he had followed in the street and changed his name at different times to Barry Bulsara, Paul Gadd and Steve Majors. He also has convictions for attempted rape and indecent assault and was seen in Ms Dando's street hours before the killing.

But at Mr George's first trial, the prosecution's case hinged on a speck of gunpowder found in his coat pocket. It was ruled inadmissible following an appeal and not used in the second hearing. Without a murder weapon or any witnesses, the prosecution faltered and police still are not sure of a motive.

Mr George protested his innocence from the moment he was taken away to the cells until his release.

The cold case review team will be told not to cover old ground, but there remains a list of theories regarding Ms Dando's killing. These have included the idea that she was the target of a hit by a Serbian assassin hired soon after she made an appeal for Kosovan refugees during Nato air strikes on Serbia. Her former boyfriends have all been excluded from the previous investigations as detectives checked whether her engagement to a gynaecologist, Alan Farthing, had caused resentment. A more simple explanation – that she was the victim of a bungled street robbery – will also be looked at again.

William Clegg QC, Mr George's barrister, said: "In considering a case of this complexity, the police and those responsible for the prosecution need to keep an open mind as far as possible as to who is responsible. I think they did close their mind after the arrest of Barry George."