Somewhere out there are the killers of Constable Ronan Kerr and somewhere, too, people who through desire or fear are protecting them, but for how long?
No matter how tiny a minority the dissident republicans may be, each and every one of them must be known within the tight-knit mainly rural neighbourhoods in which they live. I would be surprised if they were not easily identifiable.
It beggars belief in that knowledge that they could escape justice. We should be heartened by the fact that it is unlikely that they will because of the near unanimous support now existing in the nationalist and Catholic community for the peace process, devolution and power-sharing at Stormont.
Terrorism can only exist within a society if people are prepared to protect the activists. No one knows this better than the leadership of Sinn Fein. The unequivocal condemnation of Constable Kerr's murder and support for the Police Service of Northern Ireland to find his killers as expressed by Gerry Adams and Martin McGuinness at the weekend is of crucial importance. If their words were to go unheeded in this instance, Northern Ireland's future would be bleak.
The unionist and Protestant community can only watch with a sense of powerlessness from the sidelines, for this is a battle for the hearts and minds of republicans.
The likelihood of further attacks and tragic loss of life is very real. The threat of dissident republican terrorism cannot be underestimated. However all the signs suggest that such activity is galvanising the resolve of the nationalist community to reject violence and support the democratic process. It should prove a much-needed extra stimulant to vote on May 5 if only to use the ballot box to demonstrate the public's revulsion.
Constable Kerr was a son of the new Northern Ireland. In joining the PSNI, he put down his own personal marker for the future as have many hundreds of other courageous Catholic police officers. His life has been extinguished in the most callous, cowardly and barbaric way but the light of the public's desire for peace shines on brightly and is only intensified by what has happened in Omagh.
Apathy is unionism's biggest enemy, said First Minister and DUP leader Peter Robinson last week, He must know that some unionists are still trying to come to terms with the new order of political life which devolution and sharing power with republicans and nationalists requires.
The peace process has taken unionists into a transitional no-man's land. It has removed the old certainties of feeling wholly British and in no way Irish. Apathetic unionists may see devolution as unduly diluting their sense of Britishness and strengthening the Irish dimension.
How often these days do you hear unionist politicians make speeches about the benefits of being British? The constitution was barely mentioned by Mr Robinson last week when he launched his party's election campaign. Political correctness and politeness in the new power-sharing Northern Ireland means the constitutional issue has taken a back seat even though it used to be the greatest of all stimulants in winning unionist votes.
Then there is the acrimony between the Ulster Unionists and DUP. Many unionists cannot fathom why two parties are needed or understand the differences between them.
The Ulster Unionists are seen as a sad shadow of their former selves. The party appears to be a collection of parts rather than a cohesive political force and faces more uncertainty on May 5.
The Protestant middle-class, once the backbone of unionism before the onset of the Troubles, continues to display detachment and disinterest.
The Stormont Assembly's unionist MLAs are hardly an advertisement for the best talents of Northern Ireland but will that ever be the case?
Another loss of unionist support exists within the Protestant "underclass", many of whom inhabit the large housing estates of inner and greater Belfast . The end of the Troubles has made little difference to their employment prospects. Devolution has not delivered sufficiently for them. So why, they may well ask themselves, should they bother to vote?
The "brain-drain" is not what it was but it remains yet another damaging factor for unionism. The more young unionists, as distinct from nationalists, choose to find further education or employment across the water, the worse the future holds for pro-British politics in Northern Ireland.
The forthcoming elections are likely to confirm that unionists are still in the majority. The Democratic Unionists can expect to be the largest party at Stormont and provide the next First Minister. However, that does not mean the long-term overall decline in unionist support will be reversed. If the trend continues on May 5, we may be entitled to conclude that time is not on the side of unionism. Mr Robinson is right. Apathy is the greatest threat.