Today, the Supreme Court ruled by a majority of 4-3 that evidence obtained in criminal cases in breach of constitutional principles need not automatically be excluded at trial. On one level, this is a radical shift from the longstanding strictness of the application of the exclusionary rule. However, underlying it is a much more finely balanced debate than might first appear. A closer examination shows that the 4-3 split in the current Court reflects similar division of opinion in key cases from the past. The balance of opinion has in one sense only shifted very slightly; but nonetheless, in re-defining the exclusionary rule as discretionary rather than automatic, the impact of this shift has the potential to be dramatic.
In State (Trimbole) v Governor of Mountjoy Prison  IR 550, Egan J stated at 565:
“Courts have no higher duty to perform than that involving the protection of constitutional rights and if at any time the protection of those rights should delay, or even defeat, the ends of justice in a particular case, it is better for the public good that this should happen than that constitutional rights should be nullified.”
On foot of this, cases such as People (DPP) v Kenny  2 IR 110 established that evidence obtained through a deliberate and conscious breach of a constitutional right is not admissible in criminal proceedings, as to hold otherwise would constitute a breach of the requirement in Article 38.1 that criminal offences shall only be tried “in due course of law”. If the evidence is to be excluded, there must be a causative link between the violation of the rights and the obtaining of the evidence, as established in People (DPP) v Healy  2 IR 73.
The key issue in this debate is whether the breach of constitutional rights was deliberate and conscious, or whether an inadvertent breach should still lead to the evidence being excluded. A 3-2 majority of the Supreme Court in Kenny felt that the evidence should be excluded either way, as “a positive encouragement to those in authority over the crime prosecution and detection services of the State to consider in detail the personal rights of the citizens as set out in the Constitution, and the effect of their powers of arrest, detention, search and questioning in relation to rights” (per Finlay CJ at 133). In Healy, McCarthy J stated at 89 that it was irrelevant whether the Gardaí realised that they were breaching constitutional rights:
“A violation of constitutional rights is not to be excused by the ignorance of the violator no more than ignorance of the law can ensure to the benefit of a person who…is presumed to have intended the natural and probable consequences of his conduct. If it were otherwise, there would be a premium on ignorance.”
As against this, Lynch J, in his dissenting judgment in Kenny, stated at 142 that unconstitutionally obtained evidence should only be excluded if there is an “element of blame or culpability or unfairness (including any such element to be inferred by the reasonable application of the doctrine ignorantia juris haud excusat)”, and that “adequate excusing circumstances” may exist. Similar suggestions had been made in earlier cases such as People (DPP) v Shaw  IR 1. Hogan & Whyte, JM Kelly: The Irish Constitution (4th ed., 2003) state at 1107 that Lynch J’s approach “has the merit that it is not as absolute in its terms as the rule espoused by the majority, while at the same time not placing the ‘premium on ignorance’…which some feared might result from a purely subjective test.”
The majority of the current Supreme Court obviously found this to be the more persuasive view. Today’s ruling will allow for unconstitutionally obtained evidence to be admitted provided that it was obtained in good faith and that there was no deliberate or conscious breach of constitutional rights. Particularly striking were the words of O’Donnell J, who described the automatic exclusionary rule established by the majority in Kenny as “plainly wrong” and stated that it was “long past time that it was addressed”. Given the level of disagreement on this issue among both the 1990 Supreme Court in Kenny and the current Supreme Court today, this is an unusually dogmatic statement, and one with which McKechnie J expressly disagreed. Murray J and Hardiman J also wrote strongly worded dissenting opinions.
Today’s case concerned evidence obtained pursuant to a search warrant issued under section 29(1) of the Offences Against the State Act 1939. That provision was struck down by the Supreme Court in Damache v DPP  IESC 11. Strictly speaking, therefore, any evidence obtained pursuant to the warrant was unconstitutionally obtained. In Murphy v. Attorney General  IR 241 at 313, Henchy J stated that “[o]nce it has been judicially established that a statutory provision is invalid, the condemned provision will normally provide no legal justification…for transactions undertaken in pursuance of it; and the persons damnified by the operation of the invalid provision will normally be accorded by the Courts all permitted and necessary redress.” Thus, under the previous automatic exclusionary rule, any evidence obtained pursuant to unconstitutional legislation would have to be excluded.
However, where evidence is obtained by the Gardaí under the authority of legislation which has been enacted by the Oireachtas and which enjoys the presumption of constitutionality, it can hardly be said that they were “deliberately and consciously” acting unconstitutionally when serving the warrant. Applying the maxim of ignorantia juris haud excusat in such circumstances arguably does not fall within what Lynch J in Kenny imagined as a “reasonable application of the doctrine”. The majority accepted the DPP’s argument that Gardaí acted reasonably in serving warrant issued under section 29(1) at a time when they could not reasonably have been aware of any issues relating to the constitutionality of that provision. On the other hand, given that the entire purpose of the legislative provision in question is to obtain evidence for use in criminal proceedings, it seems somewhat perverse to find the legislation to be unconstitutional and yet admit the evidence. Having said that, Irish case law imposes limits on the retroactive effect of declarations of unconstitutionality. Even where a statute creating a criminal offence is struck down, persons previously convicted of that offence will not necessarily have their conviction vacated or be released from prison, notwithstanding the fact that in principle, the offence was never validly enacted to begin with (see A v Governor of Arbour Hill Prison  4 IR 88). The impact in this case is arguably less harsh, given that it relates only to the admissibility of evidence and not to the very offence, conviction and sentence involved.
The more flexible approach adopted by the Supreme Court today is in line with a number of decisions of the European Court of Human Rights. In Khan v United Kingdom (2001) 31 EHRR 1016, it was held that even where the use of surveillance had constituted a breach of the right to private and family life under Article 8, the admissibility of that evidence in criminal proceedings did not violate the right to a fair trial under Article 6, as the applicant had had the opportunity to challenge the admissibility of the evidence during the proceedings, thus preserving his right to a fair trial. Subsequently, in Allan v United Kingdom (2003) 36 EHRR 143, the Court held that once the domestic court had assessed the reliability and admissibility of the evidence, this satisfied the right to a fair trial under Article 6, whatever about the separate question of whether the process of obtaining the evidence was in violation of some other right. This case law suggests that it is difficult to establish that the admission of the evidence constitutes a violation of Article 6, as the applicants may still challenge the admission of the evidence in the domestic courts under Article 38 of the Constitution; however, the ECHR case law would not save the evidence if such a challenge was successful.
Dr Conor O’Mahony is a senior lecturer in constitutional law at University College Cork.