If the criminal justice system is not capable of delivering some justice, at least civil law is.

That was the verdict delivered by Michael Gallagher, whose son Aidan was one of 29 people, including a mother pregnant with twins, who were murdered in the Omagh bombing.

Frustrated by the failure of the police north and south to secure a criminal conviction directly related to the 1998 Real IRA atrocity, relatives of the Omagh victims took an unprecedented civil action against the men they believed were responsible for the bomb.

Seamus McKenna, Michael McKevitt, Liam Campbell, Colm Murphy and Seamus Daly were not only sued in a personal capacity. Two of the men were also sued as representatives of the Real IRA, the first time any terrorist organisation has been sued in an associative capacity anywhere in the world. It is also the first time that any alleged individual terrorists have been sued individually for a specific terrorist act.

On Monday, in a landmark ruling that could serve as a global precedent, Judge Declan Morgan — Northern Ireland’s new Lord Chief Justice in waiting — declared that McKevitt, Campbell, Murphy and Daly were responsible or liable in some way for the Omagh bomb. The action against McKenna was dismissed as the case against the Louth native was based on the hearsay evidence of his estranged wife whose evidence was deemed unreliable.

A representation order was also made in respect of Campbell as representing members of the Army Council of the Real IRA.

As a result of Judge Morgan's ruling, all other members of the Army Council of the Real IRA in August 1998 are liable for damages awarded to the relatives who fought the case. The relatives of the Omagh bomb victims, 12 plaintiffs in all, sued for £14m: they received just over £1.6m.

But the case, as the families strenuously argued from the outset, was never about the money.

The priceless quest for the bereaved lay in having someone, somewhere, held accountable.

Just as grieving relatives seek an unlawful killing verdict in a coroner's court after an accused is acquitted of murder or manslaughter in a criminal court, the relatives of the Omagh bombing desperately sought a definitive declaration that the Real IRA planned, produced, planted and detonated the bomb.

Moreover, they wanted the men they believed were responsible for the bomb named, shamed and in some sense “convicted”, if not in a criminal court, at least in some legal forum. The failure to hold anyone accountable for the Omagh bomb in a criminal court of law is, sadly, well documented.

The magnitude of the Omagh families' success in the civil courts can not be underestimated.

It could lead to similar actions being fought and won against countless terrorist organisations. Already victims of the 7/7 bombings in London and the recent terrorist attacks in Mumbai have pledged to fight similar civil actions.

Significantly, the ruling could also lead to the assets, including homes and bank accounts of suspected terrorists who are not convicted in criminal courts, being frozen and seized to meet multi-million euro compensation claims.

But the landmark victory is one born out of the failure to hold anyone accountable in a criminal court of law for the Omagh murders. Unprecedented, yes, but the ruling was secured because the lower civil standard of proof, on the balance of probabilities, was applied.

Unlike a criminal trial the families, posing here as quasi-private prosecutors, did not need to prove beyond a reasonable doubt that the men were responsible for the Omagh bombing. Instead, Judge Morgan only had to establish whether the Omagh relatives discharged the burden of demonstrating that the defendants were responsible for causing harm to the plaintiffs not through a criminal charge but through the lesser civil complaints of personal injuries and trespass, a tort.

The judge was at pains to stress that there was no criminal charge at issue in this case.

During the course of the marathon 14-month trial Judge Morgan had rejected an application by McKevitt, Murphy and Daly, that the civil proceedings constituted the determination of a criminal charge for the purpose of Article 6 of the European Convention of Human Rights which guarantees the right to a fair trial.

But many lawyers in Belfast have privately expressed unease at inferences drawn in the civil case which, in their view, “would not fly” under the burden of proof beyond a reasonable doubt.

Ultimately, there is no substitute for a criminal conviction.

The Omagh families know this only too well as their demands for a full public inquiry prove.