Shortly before Christmas, I was summoned for jury service and ended up as the foreman of a jury in a murder trial. As it happened, the trial was postponed after legal argument and the jury was discharged. The relief, I have to admit, was immense, writes Fintan O'Toole.
I had lain awake at night, haunted by the realisation that I was facing the most momentous decision of my life. One day, myself and my fellow jurors had been going about our own business. The next, we had the capacity to make one of two terrible mistakes: to destroy the life of an innocent man, or to let a man who had taken another's life get away with an awful crime.
The jury members were a good sample of Irish life, and I had no doubt that we would, between us, have enough common sense to weigh up the evidence of the witnesses.
But there might be one kind of evidence where common sense would be of little use to us, and it is the most compelling evidence of all: DNA. If DNA evidence were presented, we could listen carefully to expert testimony. But that testimony would really boil down to a single statement: "Trust me, I'm a scientist." For juries, DNA evidence is at once the most persuasive and the least accessible.
Last week, two things happened almost simultaneously. The Government decided to publish a Bill later this year that will allow for the creation of a national DNA database. And confusion over the use of DNA evidence caused immense and unnecessary suffering to the family of the Cork schoolboy Robert Holohan. These events need to be connected.
DNA profiling has been used in criminal cases in Ireland since 1987, and it is obviously a powerful tool in the determination of guilt and innocence. If and when a DNA database is established here, however, there will be a significant increase in the use of DNA evidence in court. There will be an even larger increase in the number of cases where a DNA match is the only evidence against the accused. This is because a DNA database is useful primarily when there is no obvious suspect for a crime.
Where there are suspects, their DNA can be sampled and tested. Where there are not, the database is checked. So the essential point of the database is to identify suspects where there was otherwise no obvious evidence of guilt. There has already been one case before the Irish courts where DNA provided the only evidence against the accused. The Law Reform Commission, whose report on the subject is likely to form the basis for the Government's legislation, acknowledges that "these types of cases may become more frequent with the establishment of a DNA database".
The LRC does not recommend any prohibition on the taking of such cases, nor indeed does it even specify that judges should have to warn juries of the dangers of convicting on uncorroborated DNA evidence alone. We are thus moving towards a situation where juries will be asked more frequently to find people guilty of rape or murder purely because a garda testifies that DNA was taken from the crime scene and a scientist says it matches that of the accused.
This is the context in which we need to look at what happened in the Holohan case. An initial sample of DNA from Robert's body was sent to a highly respected scientist, Dr John Whitaker, at a highly respected lab in Yorkshire. His results suggested that the chances of the sample having come from any unrelated person other than Wayne O'Donoghue were one in 77 million. As it happened, the system worked. Dr Whitaker retracted his finding after examining further evidence. The DPP decided, rightly, that the DNA evidence was far too weak to go to court.
But two serious concerns arise from this case, one hypothetical, one real. What would have happened if John Whitaker were less scrupulous and diligent, or if he had never been sent a second sample which caused him to doubt his initial findings? I know what I would have done if I'd been on a jury and was told that the chances of the DNA sample matching someone unrelated to Wayne O'Donoghue were one in 77 million: found him guilty of murder.
And there is nothing hypothetical about the other concern: grossly misleading information about the DNA sample was given to the Holohan family.
A family already traumatised by Robert's death was told - wrongly - that there was reliable evidence that he had been abused by a paedophile.
Never mind the effect of all of this on Wayne O'Donoghue. It is a horrible thing to have done to the Holohans, planting images in their heads of the last moments of a beloved child that have no real basis but that will haunt them for the rest of their lives.
We are assured that a DNA database will not be abused and that its use will be subject to the strictest controls. But the leaking of supposed DNA evidence, and of allegations that Wayne O'Donoghue accessed pornography on his computer, should be a reminder that such assurances can't be taken for granted.
The test for any legislation should be whether it will prevent what happened to the Holohans happening to anyone else.