A PSNI blunder which led to an IRA man avoiding trial over the Hyde Park bombing has sparked almost universal outrage – with the exception of Sinn Fein.
Chief Constable Matt Baggott apologised for the error which saw IRA man John Downey receive a letter of assurance that he was not wanted by police.
However, Downey was wanted by the Metropolitan Police and was arrested at Gatwick Airport last May, but the trial collapsed over the letter.
President of the Association of Chief Police Officers Sir Hugh Orde, who was PSNI chief constable at the time of the error, said: "It is a matter of great personal regret that a crucial oversight was made by a senior officer which resulted in erroneous information being sent to Mr Downey by the Northern Ireland Office and thus prejudicing the current indictment."
The matter has been referred to the Police Ombudsman.
The brother of one of the soldiers slaughtered at Hyde Park said he feels let down by the authorities.
Chris Daly, brother of Lieutenant Denis Daly (23) who died alongside three other members of his regiment, The Blues and Royals, in the infamous 1982 bombing, said the families of the victims felt "devastatingly let down". He said the blame for the "monumental blunder" lay squarely at the feet of the PSNI and has demanded an apology and full investigation into what went wrong.
"The fact the judgment determines the trial will now not take place fills the families with immense anger, frustration and disappointment," he said.
"What needs to happen is a clear flushing out of what went wrong here.
"A full and detailed explanation from PSNI as to how come this letter was issued in error and, on the two possibilities there was to correct that mistake, neither opportunity was taken, it was simply kept within PSNI.
"By being put through that angst, an apology to the families is what we seek from PSNI."
The 49-year-old said the fact Mr Downey would be returning to a normal life was "a torment" for the families left behind, for whom the grief of loss would never end.
Northern Ireland Secretary of State Theresa Villiers insisted the Government does not support amnesties for people wanted on terrorist offences.
"The PSNI will wish to reflect on lessons learned from this case and the circumstances that led to the serious error which occurred," she said.
First Minister Peter Robinson said it was an "outrage".
"Mr Downey was being tried for one of the most heinous atrocities of the Troubles, but has now invoked a get out of jail free card which he and his cohorts were handed by Tony Blair's government," he said.
Ulster Unionist justice spokesman Tom Elliott said the situation is "breathtaking".
"The fingerprints of the Northern Ireland Office are all over this. Whoever they are, wherever they are, they should be sacked. Who instructed them to write the letter? They had no right whatsoever to do this," he said.
"The scale of this is breathtaking. We are not talking about an isolated case but 187 letters issued."
Alliance MLA Stewart Dickson said this judgement has caused "enormous hurt and bitter disappointment".
Ukip's leader in Northern Ireland David McNarry added: "The question to be asked is – what other letters which are not just amnesties but freedom from justice are in circulation?"
Innocent Victims United said the situation was a "bastardisation of the justice system". Spokesman Kenny Donaldson said: "A comment made to me tonight by one widow who stands to be affected along with many others was: 'What have I done to be punished so badly?'
"This decision must be appealed. It is quite simply an outrage."
But Sinn Fein described Downey as a "valued member" and said he has been campaigning for peace for two decades.
Mid Ulster MLA Francie Molloy said Downey's arrest and charging by the British police was "a clear breach of commitments given by the British government at Weston Park and in subsequent negotiations," he said.
"Sinn Fein made it clear from the outset that the decision to prosecute John Downey was the wrong one.
"This position has been vindicated by the decision of the judge ruling in John's favour."