Supreme Court: Convicted murderer who challenged admissibility of DNA evidence has appeal dismissed

About this case:

• Judgment:
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Background

In 2010, Mr Daniel Gaynor was shot dead in North Dublin by a lone gunman. Eyewitnesses gave evidence that the gunman discarded several items as he ran away; subsequently a revolver, a cotton glove, a cream knitted glove, a baseball cap, and a hoodie were found in the area.

Mr Keith Wilson was arrested on suspicion of the murder. Refusing to cooperate with requests for a bodily sample for forensic testing, the Gardaí decided to obtain samples by collecting cigarette butts discarded by Mr Wilson. Tests revealed a match with the DNA found on the gun, glove, cap and hoodie.

There was no other evidence implicating Mr Wilson, and at his trial he challenged both the admissibility and the weight of the DNA evidence.

Mr Wilson was convicted of murder, and the Court of Criminal Appeal upheld his conviction. However, the Court acceded to an application, under s.29 of the Courts of Justice Act 1924 as amended, for a certificate that its decision involved a point of law of exceptional public importance and that it was desirable in the public interest that an appeal should be taken to the Supreme Court

Questions on appeal

The certified question before the Supreme Court was: “Is evidence of DNA samples taken from cigarette butts used and discarded by the detained person whilst in custody admissible evidence at his trial?” Additional grounds argued by Mr Wilson were also admitted by the Court.

The statutory power to take bodily samples

The Court explained that under the Criminal Justice (Forensic Evidence) Act 1990 (as amended by the Criminal Justice (Drug Trafficking) Act 1996, the Criminal Justice Act 2006 and the Criminal Justice Act 2007), consent was not required in the case of a swab from the mouth.

Although the evidence was that the investigating Gardaí were not conscious of it, they had a statutory power to take a buccal swab without the consent of Mr Wilson. In such circumstances, it would appear implicit that there would be an entitlement to use reasonable force and that Mr Wilson would have committed a criminal offence if he had obstructed them.

It was submitted that by taking the evidence outside of the statutory regime the Gardaí disregarded the statutory safeguards in respect of data retention, and gave themselves an indiscriminate power to maintain an unregulated suspect database.

The Court was satisfied that the constitutional right to privacy encompassed the intimate information about an individual contained in DNA; however this was not absolute and could be outweighed by the exigencies of the public good (see e.g. Haughey v Moriarty 3 IR 1).

A person at liberty would have no cause for complaint if his cigarette butts were picked up in a public place, or in an authorised search of his premises – as such it was impossible to hold that the rights of the detained person would be breached by the same procedure.

Equally, it would clearly be contrary to public policy to hold that the Gardaí were in the circumstances constrained to use force, and that a failure to use force rendered the picking up of the discarded items unlawful.

The Court did not consider that there was any breach of Mr Wilson’s rights, and therefore rejected this ground of appeal.

Can DNA and Statistical Evidence be sufficient?

This second issue was whether DNA evidence, no matter what the statistical probabilities, could be sufficient to establish proof beyond reasonable doubt.

The Court accepted that there was a theoretical, however slight, mathematical possibility that two unconnected persons could have the same DNA.

The real question of principle was whether that possibility must give rise to the sort of reasonable doubt which would require a trial judge not to allow the case to go to the jury in a case where there is no other evidence of identity beyond DNA profiling.

The Court was satisfied that there was clear evidence that the perpetrator of the crime discarded items of clothing as he fled from the scene; that those items were quickly identified, secured, and kept for testing; and there was nothing to suggest that the samples had been contaminated or degraded in any way.

The evidence linking the sample obtained from the clothing found at the crime scene with the perpetrator of the crime and the evidence suggesting that the comparator sample was indeed that of Mr Wilson was sufficiently robust.

In all the circumstances, this ground of appeal was rejected.

Warning the Jury

The final issue concerned whether the trial judge erred in law in failing to warn the jury of the dangers of convicting Mr Wilson in circumstances where the sole evidence of identity against him was DNA evidence.

The Court did not consider that a warning was required in a case where the only evidence of identity is confined to DNA profiling; however general guidance was outlined in the judgment as to the manner in which a trial judge might consider directing the jury in such cases.

As each of the grounds of appeal were rejected, Mr Wilson’s appeal was dismissed.