The Supreme Court rejected Christopher McDonald’s challenge to forensic samples taken while he was in Garda custody, holding there was no basis to rule that their consensual collection was unlawful. The judgment, delivered by Mr Justice Peter Charleton on 30 June 2022, addressed whether the samples could be taken with consent under common law and whether legal advice had to be available before consent was given.
McDonald had been convicted by a Central Criminal Court jury of murdering Keith Walker on 12 June 2015 at Blanchardstown Racing Pigeon Club. The prosecution’s case included DNA evidence linking McDonald to a disposable glove recovered in Sheepmoor Grove and to one source of a DNA mixture on a wig. A forensic scientist told the trial that the analysis strongly supported the suggestion that those items had been worn by the shooter.
After his arrest, McDonald signed a form consenting to forensic sampling. Gardaí took swabs for firearms residue, DNA comparison and suspected makeup. A superintendent had authorised sampling under the Criminal Justice (Forensic Evidence) Act 1990, but the trial judge found the Garda who obtained the samples proceeded under the preserved common law power, relying on McDonald’s consent. The judge admitted the evidence after a hearing on its admissibility. The Court of Appeal later rejected all grounds of appeal, finding none caused it to doubt the trial’s fairness or the verdict’s safety.
In the Supreme Court, McDonald argued that consent was not valid because he had not met his solicitor before agreeing to the samples. The prosecution argued that forensic samples are objective evidence, distinct from statements that may be affected by pressure or suggestion, and that the conviction should not be set aside even if a rights breach were found.
The Supreme Court said forensic sampling remains subject to fairness requirements and that courts must scrutinise whether apparent consent was genuinely free. But it found no evidence of coercion or trickery in this case. The judgment noted that McDonald had been given a notice of his rights and had a telephone conversation with his solicitor; it also said he consulted his solicitor before any sample was taken.
The Court concluded there was no basis to rule that the consensual taking of a blood sample from a detained person in those circumstances was unlawful. Its stated result concerns the lawfulness of the sampling. The judgment does not set out a separate order quashing or affirming the murder conviction.