The Supreme Court has reserved its decision in a significant case relating to the use of mobile phone data in criminal trials.
The court's judgment could have implications for the use of such data to prosecute criminal offences.
It may also affect convicted murderer Graham Dwyer, who has now lodged an application for permission to take a further appeal against his conviction for the murder of Elaine O’Hara, to the Supreme Court.
The outcome of the current proceedings may determine if the court decides it is necessary to hear Dwyer’s appeal at all.
The case heard by seven Supreme Court judges over the last two days is an appeal by 30-year-old Caolan Smyth against his conviction for the attempted murder of James 'Mago’ Gately in May 2017.
It also heard the related appeal of his co-accused, 55-year-old Gary McAreavey who was convicted of assisting an offender.
Smyth, from Donore, Co Meath, was jailed for 20 years in February 2021 by the Special Criminal Court.
McAreavey, from Castlebellingham, Co Louth received a three-year jail sentence.
Their prosecution relied in part on evidence relating to two mobile phones which the accused men denied were used by them.
The Court of Appeal found last year gardaí were entitled to access the mobile phone data that helped to secure their convictions.
It was the first decision of the Court of Appeal on the issue following the rulings by the Court of Justice of the EU and the Supreme Court in Graham Dwyer’s case, that Ireland’s system of retaining and accessing mobile phone data breached EU law.
The Supreme Court found the Smyth and McAreavey cases raised issues of law of general public importance and agreed to hear their further appeals.
Today, Senior Counsel for the DPP, Seán Guerin told the court the case was about the admissibility of evidence and that was a matter relating to the administration of justice.
In assessing the admissibility of evidence in a criminal trial, he said an accused person’s rights under the constitution or the EU Charter of Fundamental Rights had to be protected.
But he said the administration of justice could also be brought into disrepute if reliable evidence supporting guilt was suppressed.
The judge in a criminal trial had to engage in a balancing exercise and had to consider all the circumstances of a case he said.
Mr Guerin said the fact that the 2011 Irish legislation allowing mobile phone data to be indiscriminately retained and accessed without independent oversight breached EU law, only became clear when the Supreme Court ruled on the Dwyer case last year.
The gardaí who investigated Smyth and McAreavey were acting within the boundaries of the law and in accordance with a law that had not yet been declared invalid.
He said even though the decision of the CJEU had retrospective effect, the mobile phone evidence in this case could have been lawfully obtained and it was not true to say it was only available because of the unlawful way it was retained and accessed.
Mr Justice Gerard Hogan put it to Mr Guerin that the structural foundation of the Irish law "collapsed" in 2014, when the CJEU struck down the European directive which gave rise to the Irish legislation.
The judge said he could not understand why the "builders were not brought in" to make repairs immediately. He said this was his difficulty with everything about the case.
"There was a really clear decision in April 2014," he said, "I don’t understand why there wasn’t an immediate response to it."
Mr Guerin said he did not believe the 2014 decision had caused the "roof to fall in" in relation to the legislation and pointed to the fact that there had been pre-existing laws in Ireland allowing for data retention.
He said even though there had been a further decision by the European Court in 2016 in relation to data retention, the Supreme Court had referred the Dwyer case to Europe in 2020, believing the definitive position of the CJEU was still not clear at that stage.
The court had decided in the Dwyer case he said, that the law was not clear at all times relevant to the investigation into McAreavey and Smyth.
The judges must also decide on a separate issue raised by McAreavey relating to the level of knowledge or belief the prosecution have to prove to convict someone of assisting an offender.
