Reaction to John Downey judgement
On 20 July, 1982, four members of the Household Cavalry - Squadron Quartermaster Corporal Roy Bright, Lieutenant Anthony Daly, Trooper Simon Tipper and Lance Corporal Jeffrey Young - were killed in an IRA bomb attack in Hyde Park, London.
On Tuesday, a judge at the High Court in London ruled that a man accused of the murders, John Downey, could not be prosecuted because he had received a previous guarantee that he would not be taken to court.
Mr Downey received a letter from the Northern Ireland Office to that effect in 2007.
In his judgement halting the case, Mr Justice Sweeney said Mr Downey had received an assurance in 2007 that he would not face criminal charges, despite the fact that police in Northern Ireland knew he was still wanted by Scotland Yard.
Although police soon realised they had made a mistake, the assurance was never withdrawn.
Families of victims Roy Bright, Jeffrey Young, Anthony Daly and Simon Tipper
"It is with great sadness and bitter disappointment that we have received the full and detailed judgement and that a trial will now not take place.
"This news has left us all feeling devastatingly let down, even more so when the monumental blunder behind this judgement lies at the feet of the Police Service of Northern Ireland (PSNI).
"The torment of the families will be ongoing knowing that John Downey will be returning to his family and life will be normal for him.
"Families of the Hyde Park bombing have learnt over time to live with the consequence of the bombing but now have to learn to live with the knowledge that justice will now never be seen to be done for our lost loved ones."
Christopher Daly, brother of Lt Anthony Daly
"Unfortunately a gross mistake has happened where people did not do the right thing, but when it was recognised that a mistake had been made that mistake was compounded and there's been no sensible explanation why.
"The families really feel that they are due such an explanation.
"Justice has been thwarted due to a lack of due process, the responsibility for that lack of due process rests with the PSNI."
Peter Hain, former Northern Ireland Secretary of State
"I was astonished to hear that this prosecution had been launched in the first place, because he had received a letter from the Northern Ireland Office after painstaking investigations into whether the evidence still existed to prosecute him as a suspect for this crime and he received a letter saying he was in the clear.
"This was a critical part of the peace deal that has brought Northern Ireland from horror and evil to peace and hope and the idea that it could be unravelled in his case was astonishing to me.
"Horrible things happened in Northern Ireland's grim, evil past on all sides and what was necessary to get the peace deal that has brought Northern Ireland from evil and horror, to hope and peace, was that some of these crimes that could not be prosecuted after investigation, the suspects had to be given the all-clear."
Current Secretary of State Theresa Villiers
"This a legal procedure, it's not the result of a political arrangement.
"Around 200 people have been through an administrative scheme started by the previous government in relation to so-called on-the-runs, a number of whom were given letters similar to Mr Downey's.
"The Northern Ireland Office is conducting a check of those letters to see if a mistake was made in any other case of a similar nature to the mistake that's been uncovered in relation to Mr Downey.
"The scheme that was created by the the previous government wasn't an amnesty, the amnesty was firmly rejected by my party and the Liberal Democrats in parliament.
"The scheme was designed by the previous government merely to give a factual response to enquiries as to whether someone was wanted for terrorist offences or whether they were not.
Prosecuting counsel Brian Altman, QC
Mr Altman said both the attorney general and Crown Prosecution Service (CPS) "accept that there are no grounds upon which the ruling may be challenged".
"The attorney general and the CPS stand by the decision to bring this prosecution and believe it was right to do so despite the existence of the letter received by Mr Downey in July 2007, the terms and effect of which have now been tested before the court in public."
Current PSNI Chief Constable Matt Baggott
"I wish to apologise to the families of the victims and survivors of the Hyde Park atrocity.
"I deeply regret these failings which should not have happened. We are currently carrying out a check of these cases to ensure the accuracy of information processed by the PSNI."
Northern Ireland First Minister Peter Robinson
"This conclusion is an outrage and a dark day for justice in the United Kingdom. It is little wonder that some have lost faith in our justice system.
"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.
"No-one should be above the law and everyone should be equal under the law however this short-sighted and irresponsible process has now denied justice to victims of PIRA terrorism.
"I trust an appeal will be lodged against this decision. Every conceivable avenue should be exhausted. Justice should not have a sell-by date."
Laurence Robertson MP, Chairman of the Northern Ireland Affairs Select Committee
"I was a shadow Northern Ireland minister in January 2006 when the then Labour government dropped the on-the-runs legislation.
"I was called to a meeting by David Hanson MP, then a Northern Ireland minister, and was given the news that the government was withdrawing the bill. The government had come to this decision basically because Sinn Fein no longer supported the legislation.
"However, at no point did the minister tell me, nor did the secretary of state, Peter Hain, announce that they would seek to extend some form of amnesty to the on-the-runs.
"It seems, though, that they did indeed provide an effective amnesty to certain people by the form of a letter to those who might otherwise stand accused."
Metropolitan Police Service
"The Metropolitan Police Service respects the decision of the court.
"Our thoughts remain with the families and friends of those who lost their lives and those who were injured during the tragic events in Hyde Park on 20 July 1982.
"The strength and dignity the families have continued to show has been remarkable and we will continue to support them during this extremely difficult time.
"The case remains open and any further information that comes to light will be fully investigated."
Former PSNI chief constable Sir Hugh Orde
"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.
"As chief constable, I worked at the head of a team of very hardworking officers.
"While no organisation is immune from errors, it has become apparent recently that a very serious error was made in dealing with Mr Downey's case, which is a matter I regret very deeply.
"I am informed that the PSNI is making sure that their systems cannot allow such a grave error to happen again and they will refer themselves to the Northern Ireland Police Ombudsman for investigation."
Sinn Féin Mid Ulster MP Francie Molloy
"The arrest and charging by the British police of John Downey was a clear breach of commitments given by the British government at [the] Weston Park [talks] and in subsequent negotiations.
"Following the Good Friday Agreement both the British and Irish governments accepted that the issue of those defined as on-the-runs was an anomaly and the two governments committed to resolve the issue.
"A process was put in place to deal with outstanding cases including that of John Downey. Sinn Féin made it clear from the outset that the decision to prosecute John Downey was the wrong one."
Ulster Unionist Danny Kinahan, who was best man at victim Anthony Daly's wedding
"I was horrified when it first came through and I felt angry, and then you think, hang on, what has been going on?
"We've basically got a cock-up and we need to investigate and find out what went wrong and who is really wanted."
Traditional Unionist Voice leader Jim Allister
"This judgement is another indication of the price being paid by innocent victims for the so-called peace process. It lifts the lid on some of the rotten skulduggery involved.
"The scale of the concessions to republicans is simply unbelievable.
"It is outrageous that the government should pervert the course of justice by giving those wanted for terrorist offenses a get out of jail free card."
Ulster Unionist justice spokesperson Tom Elliott
"This news is an appalling indictment of Peter Hain and the past Labour government in their behind-the-scenes dealings. It also raises questions about who was involved in this decision-making process.
"The scale of this is breathtaking. We are not talking about an isolated cases but 187 letters issued.
"John Downey was wanted by the Metropolitan Police in connection with a brutal and savage crime. No piece of paper should be allowed to shield him from justice."
Alliance Party MLA Stewart Dickson
"This judgement has clearly caused enormous hurt and bitter disappointment to the families and victims of the Hyde Park bombing.
"Alliance has consistently opposed any amnesty in respect of crimes committed during the Troubles.
"When the previous Labour government was forced to abandon plans for 'on-the-runs' legislation which would have amounted to such an amnesty, we called for a clear and transparent system to deal with this issue which they failed to deliver."
Amnesty International's Patrick Corrigan
"Rather than political point scoring about a time which was so traumatic to so many people, it's now incumbent on the UK government to work with the Northern Ireland parties to establish a single overarching mechanism capable of comprehensively addressing the past.
"Over the years, the patchwork of measures cobbled together by successive administrations has proven completely inadequate."
Shadow Secretary of State Ivan Lewis
"This judgement raises important issues about the implementation of the scheme administered by successive governments to deal with the so-called 'on-the-runs'.
"It underlines the importance of the current all party Haass talks reaching an agreement which puts truth and justice for victims at the heart of any new system to deal with the past."
Kenny Donaldson of Innocent Victims United, an umbrella group of 21 victims organisations
"There has been a hierarchy of justice. Those who have been the victims of terrorism have received a very poor return in terms of convictions for those crimes that were inflicted.
"We don't believe yesterday's case is isolated because we know of other cases where principal suspects who were already on-the-run's, where they were on the RUC's wanted list, then disappeared off the PSNI's wanted list with no rationale given. Why was this was done, who sanctioned it and when this happened?