The Supreme Court has dismissed Keith Wilson’s appeal against his murder conviction, rejecting three challenges concerning DNA evidence used at his trial. The Court held that DNA evidence alone can, in an appropriate case, be sufficient to identify an offender to the criminal standard, but only where the evidence as a whole is robust enough to go before a jury.
Daniel Gaynor was shot dead on a public road in North Dublin on 14 August 2010. Prosecution evidence at Wilson’s trial was that a gunman wearing a peaked cap and a white glove fled and discarded items. A revolver, gloves, a cap and a hoodie were later found. Forensic testing found firearm residue on several items. DNA profiles from a cotton glove, the cap, the hoodie and the gun grips had a major profile that matched.
Wilson refused requests to provide a bodily sample while detained at Finglas Garda Station in November 2010. Gardaí collected cigarette butts he discarded in the station yard. Three were analysed, producing matching profiles that also matched the profiles from the recovered items. The prosecution’s expert estimated the chance of an unrelated person sharing the profile at one in a thousand billion. She gave a separate estimate of one in 27,400 for a sibling match.
The Court rejected Wilson’s argument that collecting and testing the cigarette butts breached his privacy rights. It said the butts had been discarded and lawfully came into Garda possession, and that generating a profile to compare with evidence associated with the crime was justified for the investigation. The Court noted that the appeal raised no evidence that the sample had been used beyond generating the profile or retained in an unauthorised database. It did not decide what limits might apply to other uses.
The Court also rejected the claim that the trial judge should have withdrawn the case from the jury because DNA was the only evidence identifying Wilson. It said the DNA evidence in this case was robust in its connection to the crime and in its collection, preservation and analysis. The jury was entitled to reach its conclusion on that evidence. The Court stressed that other cases may require an acquittal direction if the link between crime-scene DNA and the offence, the sample handling, or the statistical evidence is not sufficiently robust.
Finally, the Court ruled that no mandatory warning is required merely because DNA is the only evidence of identity. Trial judges should explain expert evidence and address issues that arise in the particular case, including statistical evidence and the risk of misleading interpretation. Having rejected all three grounds, the Court dismissed the appeal.