The murder of the senior RUC officers Bob Buchanan and Harry Breen in 1987 was among the most heinous acts ever carried out by the IRA.
Both men were shot dead as they returned to Northern Ireland after a meeting with their Garda counterparts in Dundalk.
Their killers clearly had detailed information about their movements and were able to organise an ambush from which Mr Buchanan and Mr Breen had no hope of escaping.
The IRA's overall campaign was without justification and each and every one of the murders it perpetrated were wrong.
What set the Buchanan and Breen case apart was the suspicion that the killers could have been assisted by elements within the Garda.
It was confirmed yesterday that, acting on the recommendation of the retired Canadian judge Peter Cory, the Irish government has agreed to hold a public inquiry into the double murder.
The matters arising are so grave that, even 16 years after the event, the full facts need to be established.Whether or not a full public inquiry will achieve this aim is the question which will inevitably be asked.
There are no easy answers but it is essential that detailed consideration should be given to the forthcoming inquiry's terms of reference.
Although there are indications that it could be a detailed and long-running initiative, there are strong grounds for examining the way in which the London-based Hutton probe, which investigated the circumstances leading to the death of the weapons expert David Kelly, completed its hearings within a relatively short period of time.
The Irish justice minister, Michael McDowell, was fully entitled yesterday to put the spotlight squarely on the attitude of the republican movement.
If republicans are going to speak out in favour of the staging of public inquiries, it defies logic that they might simultaneously refuse to cooperate with such investigations.
Difficult decisions will have to be taken shortly on the cases which were referred to Judge Cory within Northern Ireland.
As a first step, the judge's report on the killings of the lawyers Pat Finucane and Rosemary Nelson, the loyalist leader Billy Wright and the Portadown Catholic Robert Hamill should be published without further delay.
The views of the families of all four victims will then need to be treated with considerable importance.
As the debate develops, ways of generally reflecting the position of the relatives of those who died in the other 1,800 unsolved killings of the troubles will also have to be found.
The issue of a truth and reconciliation commission has been discussed in the past without any definite conclusions being reached. It can be expected to rise much closer to the top of the political agenda in the months ahead.
