A database of all our DNA would help fight crime and strengthen civil liberties, argues David McConnell
DNA fingerprinting (sometimes called DNA profiling), was discovered in 1985 by Sir Alec Jeffreys at the Department of Genetics in the University of Leicester. It is a method by which a genetic "bar code" for a person can be obtained from a small sample of their biological material.
Each person, excepting identical twins, has a unique genetic fingerprint, reflecting our biological uniqueness. The methods are now so powerful that genetic fingerprints can be obtained from small samples of semen, blood, skin, sputum, even from a single hair root.
An informative DNA fingerprint obtained at the scene of a crime can be used for two purposes: to exclude all persons except one as the source of the sample, and to identify one person as likely to be the source. With good samples the methods are rapid, accurate, reproducible and objective.
The use of DNA in forensic searches is one of the most significant advances of all time in forensic science. The question for Ireland is, how should we develop our DNA forensic services?
The science and technology of forensic DNA emerged during the 1980s and 1990s within the field of molecular genetics in which I have worked for more than 30 years. I have followed the developments closely, I have advised the defence in a number of cases, and I have participated in many discussions, with both lawyers and scientists. The Law Reform Commission is producing a paper on the subject.
It would be opportune to widen the discussion and I welcome the opportunity to respond to the letter from Prof Heffron (August 18th) and answer some of his understandable concerns over civil liberties.
First, however, it is important to stress the power of genetic fingerprinting to identify and avoid miscarriages of justice.
In 1996 the the National Institute of Justice of the US Department of Justice published a report Convicted by Juries, Exonerated by Science - (http://www.ojp.usdoj.gov/nij/crtpub96.htm) - which describes 28 cases of men convicted of murder and/or rape without DNA evidence who had served between them 197 years in jail. Three were on death row.
All had consistently protested their innocence and, fortunately for them, biological scene-of-crime samples had been collected and stored. The cases were re-opened and the DNA evidence showed that all 28 men were innocent, revealing shocking deficiencies, laziness and biases in the forensic services, the police and the judiciary.
Since 1996 other criminals convicted in the US, without DNA testing, have been exonerated by new DNA evidence.
I refer readers to the Innocence Project founded in 1992 at the Cardozo School of Law, New York, (http://www.innocenceproject.org/). To date 131 convicts are recorded as having been exonerated by DNA testing.
There is deep concern in the US that around 20 per cent of people arrested for sexual assault are innocent, suggesting systematic erroneous accusations and false convictions on a large scale.
It is now clear that DNA evidence is an essential tool protecting the civil liberties of those wrongfully suspected of crime. If wrongful convictions are often obtained when DNA evidence cannot be obtained, then the arguments for profound law reform and, of course, abolition of the death penalty are greatly strengthened.
DNA evidence also aids the police in apprehending suspects and the courts in making convictions. National forensic DNA databases have been set up in the UK (1995), New Zealand (1996), USA (1998) and Australia (1998).
The UK database has about two million DNA fingerprints of people convicted of serious crimes. About 200,000 new scene-of-crime DNA fingerprints have been matched with fingerprints in the database since 1995 and its usefulness in less serious crimes has been proved - it has been said that useful DNA evidence can be obtained in 40 per cent of car thefts.
Unsolved crimes for which biological samples have been retained have been reopened using new methods to get DNA fingerprints.
The Phyllis Murphy case is a good example. She was murdered in 1979, and though suspects were interviewed, no one was charged. Scene-of-crime DNA samples were fortunately preserved, and these were analysed in 1998 at a forensic laboratory in the UK. The fingerprints matched those of a suspect, John Crerar, who was convicted at trial in October 2002.
If DNA technology and a database had been available in 1979, Crerar would probably have been identified as a primary suspect within a few days, and many other suspects would not have been investigated or interviewed.
What kind of forensic DNA database should be established in Ireland, and how should it be safeguarded? Should it hold only the fingerprints of people convicted of serious crime? And if so, how do we define serious?
Such a limited database would discriminate between those on it and those not on it. It could only aid new convictions or exonerations of previously convicted serious offenders. It would do nothing directly to protect the innocence of people who have never been convicted of serious crime. In fact it would bias the investigative process leading police inevitably to concentrate on those cases which could be referenced to the limited database.
Or would the public accept the proposition - not accepted in any other country yet - that all our DNA fingerprints should be held on a database? This would help the Garda to exclude from suspicion or to exonerate all innocent members of the public, and to identify as prime suspects first as well as repeat offenders?
Such a database would have to be, and could be, absolutely secure. It could be held by an independent agency whose only task would be to declare a match or no match for a scene-of-crime sample submitted to it. The data or the biological samples need never leave the database.
In the US there are 20,000 murders and 100,000 rape cases a year. But 30 per cent of the murders and 70 per of the rape cases do not even lead to an arrest. It has been estimated that 50 per cent of rapes are not even reported.
Figures for Ireland may be less per capita, but the general picture is the same. Many violent crimes are not solved, and many rapes and other assaults are not reported. Such a database should be recognised as particularly important in dealing with violent assaults by men on women.
A comprehensive DNA database would allow many more suspects to be identified rapidly and accurately and the greater prospect of identification might encourage more victims to report rape and serious assault. Those suspected or arrested erroneously would be quickly excluded or released. The guilty would more often be convicted.
Of course we must be concerned about trust in government and government agencies, professional competence, security and a host of other matters, but I do not think any of these issues is intractable. It is because, like others, I am deeply committed to justice and civil liberty that I am convinced that a comprehensive forensic DNA system should be introduced.
This should not be "astonishing" to Prof Heffron - others hold similar views, including Alec Jeffreys. He is impressed by the fact that a comprehensive database does not discriminate for or against convicted criminals or innocent people - the innocent have nothing to fear if the system is properly established.
DNA fingerprinting has the power to exonerate everyone except the guilty and to identify a suspect with extraordinary accuracy. Civil liberty for me includes a sense of security, freedom from anxiety about personal safety, and confidence in the police and the legal system.
My conclusion is that a comprehensive DNA database will greatly strengthen our civil liberties, especially the civil liberties of women. It will very significantly protect the innocent members of our society, and enhance confidence in our judicial system. We should be asking how, not whether, a comprehensive forensic DNA service should be established.
• David McConnell is professor of genetics at the Smurfit Institute of Genetics, Trinity College. He is a member of the Irish Times Trust