Delivering judgment for the Supreme Court, Mr Justice Maurice Collins said the court had dealt with “materially identical issues” in the recent cases of DPP v Caolan Smyth [2024] IESC 22 and DPP v Gary McAreavey [2024] IESC 23.

The court also rejected a separate ground of appeal concerning the application of the so-called proviso, by which an appeal may be dismissed if the court considers “that no miscarriage of justice has actually occurred”.

Even if he had concluded that the traffic and location data in Mr Dwyer’s case was inadmissible, Mr Justice Collins said he “would have upheld the decision of the Court of Appeal to apply the ‘proviso’ and would have dismissed Mr Dwyer’s appeal on that basis”.

Background

Mr Dwyer was sentenced to life imprisonment in March 2015 following his conviction in the Central Criminal Court for the murder of Elaine O’Hara, who disappeared in August 2012 and was found dead in September 2013.

The prosecution case against Mr Dwyer relied in part on mobile phone evidence, including alleged text messages exchanged by Mr Dwyer and Ms O’Hara, and related traffic and location data. The traffic and location data was obtained by gardaí under the Communications (Retention of Data) Act 2011.

Following his conviction, Mr Dwyer launched civil proceedings challenging the 2011 Act as incompatible with EU law. The Supreme Court referred questions to the Grand Chamber of the Court of Justice of the European Union (CJEU).

The CJEU ruled in favour of Mr Dwyer, holding that the “general and indiscriminate” retention of electronic communications data for the purpose of combating serious crime is precluded by the Charter of Fundamental Rights of the European Union.

Supreme Court

Referring to his judgment in Smyth and the Supreme Court’s ruling in DPP v JC [2015] IESC 31, Mr Justice Collins said it “does not follow from the fact that evidence has been obtained in circumstances of unconstitutionality (or in breach of the Charter) that it must be excluded”.

“For the reasons set out in the majority judgment in JC, any absolute rule of exclusion exacts too high a price in terms of the adverse impact on the administration of criminal justice,” he said.

He continued: “I accept that the evidence at issue here was obtained in breach of the Charter and that it follows that the issue of admissibility falls to be determined by JC. However, for the reasons I set out in Smyth, I do not accept that necessitates a retrial.”

For reasons “which differ somewhat from the reasoning of the High Court and the Court of Appeal, I would hold that the traffic and location data evidence was properly admitted at trial,” Mr Justice Collins said.

Having decided the admissibility issue, it was “not strictly necessary” to address the proviso issue, the judge said, but he nevertheless decided to address it.

Section 3(1) of the Criminal Procedure Act 1993 provides that the appeal court may affirm a conviction “notwithstanding that it is of opinion that a point raised in the appeal might be decided in favour of the appellant, if it considers that no miscarriage of justice has actually occurred”.

Mr Justice Collins said that, even in the absence of traffic and location data, there was “overwhelming and unanswerable” evidence connecting Mr Dwyer to the mobile phones at the centre of the trial.

He said: “It follows, in my view, that there was no question of any lost chance of acquittal here and therefore no ‘miscarriage of justice’ within the meaning of the proviso. Accordingly, had I concluded that the traffic and location data was inadmissible, I would have upheld the decision of the Court of Appeal to apply the ‘proviso’ and would have dismissed Mr Dwyer’s appeal on that basis.”

Conclusion

The Supreme Court dismissed Mr Dwyer’s appeal.

In a concurring judgment, Mr Justice Gerard Hogan, who gave a dissenting judgment in Smyth, said: “Even though I dissented… I now consider myself bound by the outcome of that decision. I propose accordingly to follow Smyth, if only for reasons of stare decisis.”

Director of Public Prosecutions v Graham Dwyer [2024] IESC 39