If the argument put forward by Graham Dwyer holds, then many serious crimes against women and children, and other vulnerable people, could not be investigated or prosecuted.
This is because, in many such cases, gardaí need access to telephone data records of suspects in order to gather evidence – particularly where they would have no reason to suspect certain people of crimes.
This is how the country's top judge spelled out the implications behind the case made by convicted murderer Dwyer and his legal team.
In his Supreme Court judgement, Mr Justice Frank Clarke said the detection and prosecution of serious crime would be severely hampered if there was not a regime of general retention of communication data.
While recognising the rights to privacy of individuals laid down in European law, Mr Justice Clarke stressed that there were competing human and constitutional rights – including the rights of victims and of vulnerable people - and that the courts had to balance these rights.
Not only that, but the chief justice suggested that the final judgement of the Supreme Court may not apply retrospectively – ie not to convictions before that, including Dwyer's.
The judgement will await the rulings of the European Court of Justice (ECJ), which the Supreme Court, in a majority of six to one, has referred key questions in order to get legal clarity.
In giving his initial judgement today, Mr Justice Clarke has truly set the cat among the pigeons.
Dywer's argument is that universal data retention was illegal according to European law. The High Court ruled in December 2018 that Irish laws - which allowed mobile phone data to be retained and accessed in the investigation of serious crime – was “general and indiscriminate” and breached fundamental rights to privacy under EU law.
The State appealed the decision, claiming the consequences of not having access to retained data for the investigation and prosecution of serious crime was “stark” and that there was “no alternative”.
The High Court judgement followed a succession of European court rulings and domestic inquiries (namely the Government-ordered review conducted by Mr Justice John Murray) over the years which undermined the legal foundation of data retention powers.
This was in addition to the views of the Irish Human Rights and Equality Commission, the Irish Council of Civil Liberties and Digital Rights Ireland, whose legal action led to a landmark 2014 ruling of the ECJ.
That ruling found that the EU Data Retention Directive, upon which the Irish Communication (Retention of Data) Act 2011 was based, was incompatible with the EU's Charter of Fundamental Rights and was invalid.
In December 2016, a second landmark ECJ case (Tele2) found that EU law did apply to domestic legislation in this area and prohibited general and indiscriminate data retention.
The High Court ruled that the 2011 act was “general and indiscriminate” and breached the “fundamental right to privacy” under EU law and the European Convention on Human Rights.
Mr Justice Tony O'Connor said the act also contravened EU law by not requiring judicial approval for accessing communication data (with the legislation only requiring internal approval) and that there was “no legislative guarantee against abuse”.
In his 'Observations on and Findings of Fact' Mr Justice Clarke said the detection and prosecution of certain serious crimes are “increasingly influenced” by data retention evidence, like in Dwyer's trial.
He said that while gardaí investigating terrorism or serious crime may have suspicions in relation to people before they commit a crime, cases like that of Dwyer rarely involve situations that will enable prior suspicion.
The chief justice said: “It is, in my view, the experience of the members of the Irish courts dealing with criminal matters that some such cases have only been solved because of the availability of the type of data involved in these proceedings.”
He emphasised repeatedly how many of the cases, including that of Dwyer's, frequently involve serious offences against women, children and other vulnerable persons.
He said cases involving the grooming of children can often require similar methods for investigation and prosecution.
"In other cases, the ability to mount a successful prosecution would be severely impaired," he said.
In making “findings of fact”, he said that alternative forms of data retention – such as targeted by categories or by geography - “would be ineffective” in investigating serious crime.
He added: “The objective of the retention of data by any lesser means than that of a general data retention regime, subject to necessary safeguards, is unworkable.”
He said the investigation and prosecution of serious crime would be “significantly compromised in the absence of a general data retention regime”.
Mr Justice Clarke said there were questions of European Union law “which remain unclear” and which require to be clarified.
He said the Irish Constitution, along with the European Convention on Human Rights and the Charter, recognised “significant privacy rights” including the right of privacy to personal data.
The Irish courts had very considerable experience in “balancing” important privacy rights with the requirement for investigation and prosecution of criminal offences.
He said the rights of victims of crime form an important part of any “overall assessment” and referred to the judgments of the European Court of Human Rights (ECtHR).
The chief justice said the State had an “obligation” to vindicate, in the case of injustice done, the “life, person and good name” of a victim.
He said there was a positive obligation under the ECtHR for certain procedural obligations to victims of crime as well as an obligation “to conduct an effective investigation” into alleged wrongdoing committed against a victim.
In balancing rights of victims and a right to privacy, he said: “If, therefore, I were called on to resolve the issue of Union law concerning whether a universal system of retention is, at least at the level of principle, permissible, I would hold that it is.”
In a further blow to Dwyer, he said he was inclined to the view, in light of the ECJ rulings, that the Supreme Court may determine that any finding that data retention laws were invalid “should not apply to events which occurred prior” to that declaration – thought to mean the High Court ruling of December 2018.
This would exclude Dwyer, who was convicted in April 2015, and any other cases before December 2018.
But the chief justice did favour Dwyer in his very clear finding that the Irish regime “does not provide adequate safeguards” to meet EU requirements – namely prior approval to access data from a court or independent body and proper oversight of the regime.
Stating that Dwyer was in prison and that his appeal was now on hold, Mr Justice Clarke asked for an “expedited” hearing by the ECJ on his referral.
When that might be is not clear.
What will be particularly interesting is what the ECJ makes of the Supreme Court findings and observations in relation to privacy, given the strong, and consistent, stance it has taken on it.
“While organised crime and terrorism may in some cases give rise to prior suspicion in advance of the commission of any particular specific crime, the type of serious crime with which these proceedings are concerned rarely involves any circumstances which could reasonably be known to investigating authorities in advance and which could lead to prior suspicion. It is, in my view, the experience of the members of the Irish courts dealing with criminal matters that some such cases have only been solved because of the availability of the type of data involved in these proceedings.
“It seems to me that cases of the type described, of which this case is a particular example, frequently involve serious offences against women, children and other vulnerable persons. In addition to the charge of murder of a vulnerable person, which is the subject of the underlying criminal proceedings involving Mr Dwyer, cases involving the grooming of children can often require similar methods for investigation and prosecution. As already noted, in a significant number of such cases, it would not be possible to detect, let alone adequately prosecute, the perpetrator without access to telephony data of the type with which this case is concerned. In other cases, the ability to mount a successful prosecution would be severely impaired.
“It seems particularly important to emphasise, therefore, that it is not possible to access that which has not been retained. If, on the basis of the argument put forward on behalf of Mr Dwyer, it is not permissible to have “universal” retention of data, notwithstanding the robustness of any access regime, then it follows that many of these serious crimes against women, children and other vulnerable persons will not be capable of detection or successful prosecution.
“In the light of the evidence tendered in these proceedings and of the findings of fact which I propose that this court should make, it seems to me that significant regard would have to be attributed to the fact that many serious crimes against vulnerable people are most unlikely, on the undisputed evidence, to be capable of successful prosecution in the absence of a system of universal retention. In that context, I would consider that considerable weight must be attached to the undoubted rights of the victims of such crime, which rights will be impaired to a very significant degree indeed if it should prove impossible to detect or successfully prosecute the perpetrators of crimes against them.
“If, therefore, I were called on to resolve the issue of union law concerning whether a universal system of retention is, at least at the level of principle, permissible, I would hold that it is. To consider otherwise is to say that the very significant rights of the victims of serious crime, including many vulnerable victims, have to be set at nought.”
Compiled by Cormac O’Keeffe