European Court of Justice to rule next month on Graham Dwyer data retention case

Phone data played key role in securing conviction for Elaine O’Hara’s 2012 murder

The European Court of Justice (ECJ) will give judgment next month concerning the far-reaching challenge by convicted murderer Graham Dwyer over Ireland’s mobile phone data retention regime.

The State’s appeal to the Supreme Court against a High Court decision that the data retention law should be struck down has been on hold pending the ECJ ruling.

The ECJ press office said on Monday that the judgment would be given on April 5th.

An opinion last year from an advocate general, a senior judicial adviser to the ECJ, firmly confirmed that court’s case law that general and indiscriminate retention of electronic communications traffic and location data is permitted only where there is “a serious threat to national security”.


It said this “does not include the prosecution of offences, including serious offences”. Given Irish law permits general retention for two years, it does not comply with EU law, the opinion said.

The advocate general said access by the competent national authorities to retained data does not appear to be subject to prior review by a court or independent authority, as required under EU law, but rather to the discretion of a Garda of certain rank.

The Irish Supreme Court will have to decide whether that meets the requirement of prior review and independent authority, the opinion stated.

Cannot limit

In a further blow for the State, the opinion reiterated that a national court cannot limit in time the effects of a declaration of illegality of domestic legislation incompatible with EU law.

The time issue is crucial because the State has relied on a 2011 law, based on a 2006 European Directive struck down in 2014 by the ECJ, in accessing and retaining data for many prosecutions.

The case has potentially huge implications for the battle against serious crime in Ireland and all EU member states. While the opinion is not binding on the ECJ, legal sources believe it appears unlikely, given its case law since 2014, the ECJ’s final judgment will not be in line with the opinion.

However, the ECJ and Supreme Court decisions on Dwyer’s data appeal may not be determinative of his separate appeal against his murder conviction. It will be for the Court of Appeal here to decide on the admissibility of the phone evidence, whether other evidence supports the conviction and whether the conviction is safe or not.

Childcare worker

Mobile phone data played an important role in securing Dwyer’s 2015 conviction for the murder of childcare worker Elaine O’Hara in August 2012.

In 2018, the High Court upheld Dwyer’s claim that the 2011 Irish law under which the metadata was held breached EU law. The Irish law was based on a 2006 EU directive on data retention struck down by the ECJ in 2014, in a case by Digital Rights Ireland, on grounds that the universal and indiscriminate retention of mobile phone and internet data breached privacy and data protection rights.

The High Court held that the 2011 law was contrary to EU privacy law because it allowed for indiscriminate data retention without adequate safeguards, including a prior independent overview of data access requests.

The State appealed to the Supreme Court which referred issues of EU law to the ECJ and its judgment on those and similar issues in cases referred by the German and French courts will be delivered on April 5th.

Mary Carolan

Mary Carolan

Mary Carolan is the Legal Affairs Correspondent of the Irish Times