Accused IRA bomber to avoid prosecution after 'catastrophic failures'

John Downey, 62, of County Donegal, Ireland, was charged by the Crown Prosecution Service (CPS) in May with the bombing in Hyde Park on July 20, 1982.

Victims killed in the explosion, Roy Bright, Anthony Daly, Simon Tipper and Geoffrey Young, were members of the Royal Household Cavalry’s Blues and Royals.

The regiment’s armoured category is based at Combermere Barracks in St Leonard’s Road, Windsor.

The case against Mr Downey fell apart after it was revealed he had been given a 'clear written assurance' in 2007 from the Secretary of State for Northern Ireland and the Attorney General that he would not be prosecuted, as part of a deal in the Northern Ireland peace process.

In reality, Mr Downey was wanted by the Metropolitan Police in relation to the Hyde Park bombing and had been almost continually since May 1983.

On 19 May 2013, he was arrested at Gatwick Airport en route to Greece and was charged with four counts of murder and one of doing an act with intent to cause an explosion.

The trial at the Old Bailey, heard from the CPS that the letter was the product of error during the Police Service of Northern Ireland’s Operation Rapid as opposed to any act of bad faith.

In his ruling on Friday, Mr Justice Sweeney said: "The catastrophic failures of Operation Rapid in 2007 were further compounded in 2008, when no step was taken to put matters right.

“The public interest in ensuring that those who are accused of serious crime should be tried is a very strong one.

“However, in the very particular circumstances of this case it seems to me that it is very significantly outweighed in the balancing exercise by the overlapping public interests in ensuring that executive misconduct does not undermine public confidence in the criminal justice system and bring it into disrepute."

The CPS has decided not to appeal the judgement.