National Prosecutors' Conference: The Director of Public Prosecutions has called for new legislation to establish a DNA database.
Speaking at the annual National Prosecutors' Conference at the weekend, James Hamilton pointed out that the Law Reform Commission would publish a report on the issue in the autumn, and said he hoped it would be followed by the necessary legislation.
Already DNA evidence had provided a powerful tool in a number of cases in this country, he said. "But in the absence of a DNA database, DNA evidence has its limitations.
"In order to use DNA evidence we need to find DNA at the scene of a crime. But if we do not have a DNA database gardaí then have to obtain samples individually from suspects and analyse them so as to obtain a DNA profile for each suspect. If the person who committed the crime never makes it onto the list of suspects, the DNA evidence will prove nothing."
He pointed out that in its consultation paper published last year, the Law Reform Commission recommended that a DNA database contain the DNA profiles of every person convicted of a crime for which they were sent to prison. These profiles could then be compared with DNA evidence found at the scene of a crime.
"Many and probably most crimes are committed by persons who do have criminal records, and this is particularly the case in relation to organised crime," said Mr Hamilton.
"In the context of organised crime the ability to use DNA evidence could be particularly important since it is often difficult to get witnesses to testify against gangs who are prepared to use extreme violence to get their way."
However, he said he disagreed with the LRC's consultation paper in that it did not propose that DNA should be taken from people convicted of serious crimes but not sent to prison. "While I agree that persons found guilty of extremely minor offences should not be compulsorily sampled, I do not think the solution is to confine compulsory sampling to persons who are sent to prison. There are, for example, many serious sentences where a suspended sentence is imposed, sometimes a lengthy sentence."
He added that the use of DNA evidence, as well as allowing many difficult crimes to be solved, also exonerated people wrongly suspected of having committed offences.
Martin Fairely, head of the DNA section of Strathclyde police in Scotland, said the introduction of a DNA database there had allowed the solution of a number of serious crimes, including the murder of a girl 23 years earlier.
He said that DNA samples were taken from all those arrested in Scotland, including for minor offences like a breach of the peace. If a person was subsequently acquitted, the sample was destroyed.
In one case where a 78-year-old woman was sexually assaulted and beaten to death in her home, 3,000 males living in the vicinity were sampled but no match was found.
Two years later a man was arrested for breach of the peace and sampled. He turned out to have "a horrendous record of violence". His DNA matched that found at the scene, and he was charged and convicted. It emerged he had visited his nephew in the same estate on the day of the murder.
In another case where two elderly women were raped, and one died, a DNA sample from a man arrested on a drug offence 12 years later was found to match the sample at the scene.
Mr Fairley said that DNA evidence was particularly useful in solving "volume crimes", like car crime and burglaries. Two hundred people a month cut themselves breaking into cars, he said, leaving DNA at the scene.