THE SUPREME COURT
[Appeal No: 398/2012] Denham C.J.
The Director of Public Prosecutions
Accused/RespondentJudgment of Mr. Justice Clarke delivered the 15th April, 2015.
1.1 This case involves a request to reconsider the so called exclusionary rule. The case also involves the scope of appeals which can be brought to this Court by the prosecutor/appellant ("the D.P.P.") under section 23 of the Criminal Procedure Act, 2010 ("section 23").
1.2 Insofar as they are relevant, the facts of this case have been fully set out in other judgments of the Court, and it is unnecessary to repeat them in detail here. In summary, while the accused/respondent ("Mr. C.") was at trial before the Circuit Court (Her Honour Judge Ring), evidence was excluded on the basis of an application of the exclusionary rule as identified and defined by this Court in D.P.P. v. Kenny  2 I.R. 110 ("Kenny"). There was no dispute on this appeal that, applying the exclusionary rule as so defined, Her Honour Judge Ring was obliged to exclude the evidence concerned. With the relevant evidence excluded, the case against Mr. C., in substance, collapsed.
1.3 The D.P.P. has brought an appeal to this Court under section 23 seeking to review the decision to exclude the evidence in question. It would be fair to say that in so doing, the D.P.P. has invited this Court to take the view that Kenny was wrongly decided and that a different, and it might be said more nuanced, exclusionary rule should be applied. Two separate but connected issues arose on this appeal concerning the question of whether it was open to the D.P.P. to bring an appeal under section 23 in the circumstances of this case. The first stems from the fact that it is accepted that the trial judge had no option but to decide as she did given that she was bound by the decision of this Court in Kenny. That issue turns on the proper interpretation of section 23 and, in particular, whether it can be said that the trial judge had "erroneously excluded evidence" in circumstances where it is accepted that the trial judge was bound to follow Kenny and properly applied Kenny to the facts.
1.4 So far as the second issue is concerned, it is first necessary to record the circumstances which led to that issue being considered by the Court. After the appeal had concluded and in the course of its deliberation it became clear to the Court that there was, potentially, a further issue concerning the availability of an appeal under section 23 which might, potentially, have application to this case. In those circumstances, the Court invited further written submissions and arranged for a further oral hearing to deal with that second issue. The question derives from the requirement, to be found in section 23 itself, that the evidence said to have been erroneously excluded must be "compelling" evidence. That term is defined in the section, and an issue arises as to whether, in the circumstances of this case, the evidence which was excluded by the trial judge can be said to be "compelling" evidence as so defined. It should also be recorded that, in the context of the further hearing to which I have referred, a motion was brought on behalf of the D.P.P. seeking to introduce further evidence on the appeal. That application was, in substance, a fallback position to the primary argument of the D.P.P., which was that there was sufficient material available to the Court, from the record of the proceedings before the Circuit Court, to enable this Court to conclude that the excluded evidence was "compelling evidence" as defined. I will turn shortly to the two questions which arise concerning the availability of an appeal under section 23.
1.5 However, on the assumption that an appeal of the type identified does lie, then the substantive question which arises is, in effect, as to whether Kenny was correctly decided, and if not, as to what the appropriate test should be for the admission or exclusion of evidence obtained in circumstances where the method of taking the evidence concerned involves a breach of constitutional rights. While that question arises at the level of broad principle it is, of course, important to note that it arises on this appeal in the context of the specific issues and facts which are relevant to this case.
1.6 Finally, for completeness, it should be noted that one of the issues which would arise, in the event that an appeal lies and that the D.P.P. successfully persuades the Court that evidence was wrongly excluded, is as to whether a retrial should be directed. For reasons which will become apparent, it does not necessarily follow that a retrial should be directed even if it is found that "compelling evidence" was erroneously excluded. It should be noted at this stage that counsel on both sides agreed that a decision on a retrial (if it arises) should be left over until after the substantive issues have been determined. For reasons with which I will deal in the context of the structure of section 23 itself, it is clear that, unless it is considered appropriate to direct a retrial, the D.P.P.'s appeal must be dismissed and the acquittal affirmed. It follows that it is only possible, at this stage, to determine whether, in the event that an appeal lies, the relevant evidence was erroneously excluded. Even if such a conclusion is reached it follows that it will not be possible to determine the result of this appeal until the Court has had an opportunity to decide whether a retrial should be directed.
1.7 However, as it is clear that it would only be appropriate for this Court to embark on a consideration of the exclusionary rule if an appeal lies in the first place, I turn first to that question.
2. Does an Appeal lie under Section 23?
2.1 The backdrop to section 23 has to be the starting point. Historically, save for a brief period, no appeal lay from an acquittal in criminal proceedings. Immediately prior to the enactment of section 23, the only appeal which lay to this Court from an acquittal (whether in respect of the whole or part of an indictment) was a consultative appeal “without prejudice to the verdict or decision in favour of the accused person” which arose under s.34 of the Criminal Procedure Act 1967 (as now substituted by s.21 of the Criminal Justice Act 2006). Section 34 permits the Attorney General in any case, or, if he or she is the prosecuting authority in the trial, the D.P.P., to “refer a question of law arising during the trial to the Supreme Court for determination”.
2.2 In that context, it is necessary to make a brief reference to The People (Director of Public Prosecutions v. O'Shea  I.R. 384. In that case, this Court was divided three to two. However, the majority view was that Article 34.4.3 of Bunreacht na hÉireann, which, as of the time of O'Shea, provided that this Court should "with such exceptions and subject to such regulations as may be prescribed by law" have appellate jurisdiction from all decisions of the High Court, overrode the common law position that there was no appeal from acquittal in criminal proceedings. So far as criminal proceedings in the Central Criminal Court (being the High Court exercising its criminal jurisdiction) were concerned, it was, therefore held that an appeal against acquittal lay. Indeed, one of the arguments put forward was that s.34 of the Criminal Procedure Act 1967, by providing for a without prejudice appeal, had impliedly limited this Court's appellate jurisdiction. That argument was rejected by the majority.
2.3 It should, of course, also be noted that this Court, in People v. Quilligan (No. 2)  I.R. 46, was divided once again on the question of whether, after a successful appeal, a retrial could be directed. Henchy and Griffin JJ. took the view that the Court could not so direct in the absence of express statutory provision and, indeed, doubted whether such provision could be made in a constitutionally valid form. Walsh and McCarthy JJ., on the other hand, held that the right of appeal carried with it an inherent jurisdiction necessary to give effect to that right of appeal and, thus, to order a retrial. Hederman J. found it unnecessary to decide the issue of principle because he took the view that, on the facts, no retrial should be ordered. Before that issue was finally resolved, the right of appeal with prejudice by the prosecution from a decision of the Central Criminal Court was excluded by statute (see s. 44 of the Courts and Courts Officers Act 1995).
2.4 While the matter is not free from doubt, it follows that there is at least a significant argument that the Constitution, at least in the manner in which it has been interpreted to date, actually permits a with prejudice appeal at least so far as criminal trials conducted in the Central Criminal Court are concerned. As long as such appeals were, however, excluded expressly by statute it was no longer necessary to give any further consideration to any of the issues which might arise in that context.
2.5 However, in 2010, section 23 was enacted, which provides for a form of appeal which can, at least if this Court so directs, be with prejudice to the position of the relevant accused, for it can lead to a retrial carrying with it, obviously, the possibility that the accused might be convicted on that retrial. In material part, section 23 reads as follows:-
It will be seen that, in order for an appeal to lie under section 23(3), there must be an error on the part of the trial judge in the sense that evidence must have been erroneously excluded or a direction to the jury must be wrong in law. At the level of first principles it is possible to envisage three circumstances in which the D.P.P. might wish to appeal against an aspect of the decision of a trial judge in a criminal case.
2.6 First, at a simple and straightforward level, it is possible to envisage a case where the D.P.P. wishes to suggest that the trial judge simply made an error in applying uncontroversial and well established legal principles to the circumstances of the case in question. There can be little doubt but that an appeal under section 23 lies in such circumstances. If the D.P.P. were to be proved to be correct then the trial judge would clearly have committed an error either by erroneously excluding evidence or by giving a direction to the jury which was wrong in law.
2.7 Second, there may be a dispute, to a greater or lesser extent, as to the proper interpretation of the law applicable to some material aspect of the case. The D.P.P. may wish to invite this Court to overrule the view which the trial judge took. In cases where there may be a lack of clarity as to the legal position on the issue in question, it is difficult to see how there could be any question but that an appeal under section 23 lies. If a trial judge chooses a particular approach to the legal issue in question, with which this Court ultimately disagrees, then it is again difficult to see how that could be characterised as anything but an erroneous exclusion or a wrong direction (even if, in many cases, it may well be a wholly understandable error in the light of the uncertainty of the law on the topic in question). However, that is not the situation which arises here.
2.8 This case is of a third kind. As noted earlier, the complicating factor, on the facts of this case, is that the law on this issue has appeared to be clear since the decision of this Court in Kenny. It is not, as has been pointed out, suggested by anyone that the trial judge did not correctly apply the exclusionary rule in the manner in which that rule is addressed in Kenny, or did not do so in a proper fashion. The argument, therefore, arises as to whether it can be said that the trial judge, in those circumstances, erroneously excluded the relevant evidence even if this Court were to take the view that Kenny was wrongly decided in a manner material to the issue of the admissibility of the relevant evidence in this case. In one sense, the issue can be put thus. Can it be said that a trial judge erroneously excluded the evidence in question if the trial judge properly applied the established case law of a higher court by which that trial judge was bound, even if this Court takes the view that the established case law in question requires to be revisited in a material respect?
2.9 That is, indeed, an important question, for it has the potential to have a significant effect on the scope of appeals which are permitted under section 23. As already noted, there would not seem to be any doubt but that section 23 applies in a case where it is suggested that the trial judge has simply misapplied a clear and established legal principle. Likewise, there can be little doubt but that section 23 can be used to mount an appeal which seeks to clarify an area of law over which there may be legitimate doubt. However, if the suggestion that section 23 can not be used as a means of inviting this Court to reconsider clear previous authority which bound the trial judge in question is correct, then there could be no basis for the D.P.P. seeking to invoke that section in the circumstances of this case. It should be recorded that counsel for Mr. C. did not raise this argument in the written procedure and accepted in oral argument that an appeal did lie. The suggestion to the contrary came from questions put by the Court. Both counsel were, therefore, agreed that it can be said that a trial judge had erroneously excluded evidence even though the trial judge had properly applied case law by which that judge was bound. Nonetheless, it remains for the Court to interpret section 23 in the context of the issues sought to be raised by the D.P.P. on this appeal.
2.10 It is of some importance, in my view, to note that the logic of the argument would appear to apply equally to a case where the D.P.P. sought to argue that this Court should depart from previously established case law of the Court of Criminal Appeal or, indeed, now the Court of Appeal. A trial judge is every bit as bound by the established case law of the Court of Appeal as of this Court. If a trial judge can not be said arguably to have been wrong (i.e. to have erroneously excluded evidence or given a direction which was wrong in law) when following the established case law of this Court, then it would equally follow that a trial judge could not be said arguably to have been wrong where the trial judge followed established case law of the Court of Appeal. If that is so, it would follow that no appeal under section 23 could arise in those circumstances either.
2.11 In passing, it should be noted that, unlike section 23 which specifies the circumstances in which an appeal with prejudice will lie to this Court (in subsection (3)), s. 34 of the Criminal Procedure Act 1967 (in its current form) does not limit or make any reference to the subject matter or the circumstances where a “question of law” can be referred to the Supreme Court without prejudice to the verdict or decision in favour of the accused. In those circumstances it appears that, even if it was not open to the D.P.P. to appeal the acquittal of Mr. C. “with prejudice” on a question of law under section 23, it would be possible for the D.P.P. to refer a question of law to the Supreme Court “without prejudice” to the acquittal, under s. 34 of the Criminal Procedure Act 1967, as substituted.
2.12 However, whatever may be the practical consequences, the scope of appeal which is permitted under section 23 depends on the proper construction of that section. If, under that section as properly interpreted, an appeal in certain circumstances does not lie, then the fact that there may be adverse consequences of so ruling is really neither here nor there. A person cannot be placed in jeopardy of a possible criminal conviction by being subjected to an appeal with the possibility of that appeal being successful and a retrial resulting in conviction unless the law so allows. The issue, therefore, comes down to one of statutory construction.
2.13 The starting point has to be to assume, for the sake of argument, that Kenny was wrongly decided. It follows that a decision to exclude evidence on the basis of the precise exclusionary rule as defined in Kenny may be wrong. I say "may be" wrong, for, of course, it does not necessarily follow that the relevant evidence might not also be properly excluded by reference to whatever criteria or test this Court might identify as representing the proper constitutional balance.
2.14 On the assumption that Kenny was wrongly decided, and that, applying the proper test, the relevant evidence should have been admitted, it is clear that the decision to exclude that evidence was wrong. However, even though the decision was wrong, it is suggested that it cannot be said that the trial judge, in making that decision, erroneously excluded the relevant evidence because the trial judge was, it is accepted, bound to apply Kenny.
2.15 It might be said, in that context, that a reversal by this Court of a previous binding decision can have retrospective effect. There is a sense in which that is true. The need for a court to exercise some caution in revisiting existing case law has been addressed, in admittedly very different circumstances, by this Court in both M.R. v. An tArd Chláraitheoir & ors  IESC 60 and H. v. H.  IESC 7. As noted in those judgments, one of the difficulties which can be encountered as a result of a significant change in case law is that legal theory in this jurisdiction suggests that the "new" position adopted was always the correct position.
2.16 It is, of course, the case that the issues which arise on this appeal are, in substance, constitutional issues. The decision in Kenny is itself a determination of the proper balance to be struck in recognising and vindicating the constitutional rights and values at stake. Likewise, this Court is, in this case, concerned with the same question. Such constitutional issues are always subject to review in the light of prevailing circumstances, and any such review will have the potential to be retrospective at least so far as the case giving rise to the review itself is concerned.
2.17 But perhaps of greater importance is the fact that the Court, on this appeal, is concerned with a question of the admissibility of evidence rather than with a substantive issue directly affecting the substantive rights, obligations and liabilities of individuals or bodies. The consequence of a reappraisal of the case law in respect of the law of evidence is, in my view, while important, potentially less significant than a similar reappraisal of substantive law. A person either has, or has not committed a criminal offence. A reappraisal of the ingredients of that offence could have very significant consequences. A person might, if such a reappraisal had retrospective effect, be found guilty of an offence of which that person could not, no matter what the evidence was, have been found guilty on the basis of the law as it was understood at the time when the events said to constitute the offence in question occurred.
2.18 The Oireachtas is precluded, under Article 15.5 of Bunreacht Na hÉireann, from the enactment of retroactive penal legislation. A suggestion that the courts, by judicial reinterpretation, might achieve the same effect and, in the words of Article 15.5, "declare acts to be infringements of the law which were not so at the date of their commission" might well give rise to significant constitutional questions. However, this appeal is not concerned with retroactive penal legislation as such. Rather, this appeal is concerned with the law of evidence, albeit an aspect of that law which has significant constitutional influence.
2.19 But a change in the law of evidence does not make something illegal which might have appeared to have been legal at the time of its occurrence. Rather, a change in the law of evidence may permit a party (or the prosecution in the criminal context) to be able to prove something which they might not have been able to prove under the law of evidence as it was previously understood. But if, in the light of the law as reinterpreted, there is now cogent and admissible evidence that an offence was actually committed, then all that the reinterpretation of the law does is to permit an existing offence to be proved when, under the previous interpretation of the law, it might not have been possible to do so. The constituents of the offence do not change in any way.
2.20 While there is a sense in which such a course of action operates retrospectively, it seems to me that it does so in a very different way, and with significantly less constitutional difficulty than might arise if an attempt were made to redefine the elements of a criminal offence in a way which would render acts to be infringements of the law when those same acts would not have been considered to be such infringements on the basis of the law as it was understood at the time when those acts were committed. For those reasons, I do not consider that the element of retrospection which would arise from reconsideration by this Court of Kenny would be significant.
2.21 On that basis, I return to the proper interpretation of section 23. If it was wrong to exclude the evidence in question, then, in my judgment, that is an error even if the trial judge was, by virtue of the hierarchy of the courts, bound to follow Kenny (unless and until it is overruled or redefined by this Court). The fact that a trial judge may have been bound to follow what transpires to be an erroneous decision of this Court does not prevent the trial judge from being properly described as having erroneously excluded relevant evidence. On that basis, I am satisfied that an appeal to this Court under section 23 lies.
2.22 It is illustrative, in that context, to look at the situation which might arise in a case where the defence sought to invite this Court to revisit a material aspect of the jurisprudence. Assuming that it had to be accepted that a trial judge had correctly admitted evidence on the basis of the proper application of the existing case law of, for example, this Court, on what basis might it be said that an accused could then appeal to this Court against a conviction sustained on the basis of such evidence, and in so doing to invite this Court to revisit its own jurisprudence? There are only two possibilities. Either it is possible for an accused to appeal against a decision of a trial judge even though the decision of that trial judge was correct in the sense that the trial judge properly made the relevant decision in accordance with case law by which that judge was bound, or it is possible to regard a trial judge as being in error even if the trial judge applies case law by which that judge is bound in circumstances where this Court considers that the existing case law itself is erroneous. No other logical possibilities exist. The whole structure of any appellate system normally implies that the appellant has identified something which occurred in the trial court which was erroneous. I would qualify that observation by noting that there are, of course, exceptional cases where new and admissible materials have become available which may result in a successful appeal even though no error can be pointed to as to the manner in which the trial was conducted. But in the absence of such exceptional circumstances, how does an accused appeal in circumstances where the trial judge properly applied existing case law? I cannot see that it makes logical sense to treat the accused as having a right to appeal against a correct decision of a trial judge. But unless that is so, how may a decision, which is against the accused, but which is in accordance with established case law, to ever be the subject of an appeal unless such a decision is to be regarded as erroneous because the case law which was applied is, likewise, found to be binding but also erroneous?
2.23 Indeed, in that context, it is instructive to consider what might have occurred had the trial of Mr. C. taken place after the decision of the High Court in Damache v. D.P.P.  2 I.R. 266. The admissibility issue in this case stemmed from questions over the validity of warrants of the type used both in Damache and here. It must be recalled that the High Court, in Damache, upheld the validity of warrants of that type. Her Honour Judge Ring would have been just as bound by the decision of the High Court in Damache if that represented the state of the law when the matter came before her as she ultimately was bound by the decision of this Court in the same case. On what basis might Mr. C. have appealed in that scenario? It can hardly be doubted that, armed with the decision of this Court in Damache, had it been delivered by the relevant time, Mr. C. would have argued on appeal that the evidence against him was wrongly admitted and that his appeal should be successful. But in so doing he would, in substance, be arguing that the trial judge wrongly admitted the evidence even though the trial judge was applying a decision of the High Court by which that trial judge was bound.
2.24 Indeed, in that context, mention should be made of the practice sometimes properly adopted by counsel of reserving their position to argue a point on appeal. Counsel adopt that position where forced to accept that a trial judge is bound to find against them on the relevant point by virtue of binding authority but where it may be perceived that a higher court, not so bound, might revisit the jurisprudence. Would counsel for an accused not be entitled to appeal against the admission of evidence even if adopting that practice in making a formal objection to the admissibility of the evidence concerned? Would the decision of the trial judge nonetheless be argued on appeal to have been erroneous? I do not see any legitimate basis for treating a decision in favour of the accused as not being erroneous but treating an almost identical decision against the accused as being erroneous.
2.25 I am also strengthened in that view by a consideration of the relevant provisions of section 23 taken as a whole. As already noted, the circumstances in which an appeal lies under section 23 concern either the "erroneous" exclusion of evidence or the giving of a direction which is "wrong in law". If this Court were to come to the view that a previous decision of this Court was itself wrong, how then could it be said that a direction to the jury based on that previous case law was not itself "wrong in law"? The fact that it would have been more than appropriate for a trial judge to have directed the jury based on the case law of this Court would not prevent such a direction from being "wrong in law" if this Court were to ultimately conclude that its earlier case law needed to be revisited in a material respect. I do not see that there is any basis for interpreting the scope of appeals which lie in respect of directions to the jury (which must be said to be wrong in law) in a materially different way to the scope of the appeals which lie in respect of the exclusion of evidence (which exclusion must be said to be erroneous).
2.26 Furthermore, I am not convinced that arguments about double jeopardy play any role in this debate. If an appeal properly lies, then it forms part of the same process as the trial itself. If there is a successful appeal and a retrial is directed, then that retrial, in turn, is part of the same process. Any earlier acquittal is, therefore, set at nought by a successful appeal by the D.P.P. under section 23 and it cannot, in my view, therefore, be properly regarded as an acquittal any more than any judgment and order of any court which is altered on appeal can be regarded as a binding judgment at all save in the limited historical sense that it was, up and until the time when it was overturned on appeal, the position adopted by a court of competent jurisdiction.
2.27 The question of double jeopardy properly arises when whatever procedure is available for the trial of an accused in a relevant jurisdiction runs its natural course and results in an acquittal. The issue which then arises is as to the circumstances, if any, in which it may be permissible to commence an entirely new process or reopen a process which has come to a natural end. But such is not the case here. The issue does, of course, depend on the proper interpretation of section 23. However, there can be no doubt that section 23 must be taken to apply in some circumstances. In those circumstances, an accused can properly be convicted after a retrial which has been directed resultant on a successful appeal by the D.P.P. under section 23. It is not correct, in my view, to characterise such a retrial as being in any way affected by any principles against double jeopardy. Rather, such a retrial is part of a single, continuous process in which an appeal court has corrected the error of a trial court, directed a retrial, and the result of that retrial will stand as the proper determination of the criminal process in the case in question.
2.28 That leads to the second issue which arises as to the scope of section 23, being the requirement that the excluded evidence be "compelling".
3. Compelling Evidence
3.1 First, it is clear that, by virtue of subsection (3), the basis of a successful appeal must be a finding that "a ruling was made by a court" … "which erroneously excluded compelling evidence". Compelling evidence is defined in subsection (14) as meaning that the evidence is reliable, of significant probative value, and such that, when taken together with all other evidence adduced a jury might properly convict.
3.2 It has to be said that this aspect of the section in its current form raises a number of potential difficulties. First, what is under consideration is evidence which was actually excluded at the trial. The potential for an appeal under section 23 in respect of an evidential ruling of the trial judge only arises where the trial judge does not permit the relevant evidence to be tendered. There may be significant differences, from one case to the next, as to the extent to which it may be clear from the record of the trial as to what the evidence, which was sought to be tendered, would have been had the trial judge ruled differently. In this case, the admissibility issue centred on certain statements made by Mr. C. while in garda custody. Thus the statement which the prosecution would, doubtless, have sought to prove in evidence was available in a written form. Although the evidence of that statement was not, precisely because the trial judge ruled it out, ever placed before the Court in a formal way, nonetheless it is possible to identify, on the facts of this case and from the record of the trial, certain features of the excluded evidence.
3.3 However, that might not always be the case. An objection might be taken to the admissibility of evidence on the grounds of hearsay. Precisely because the objection succeeded, a trial judge might not allow the question to be answered, and thus there may be no record of what the witness would have said had the question been permitted. In such a case it might (but would not necessarily) be the case that the Book of Evidence may have given an indication of the answer which the relevant witness was expected to give. It might or might not be the case that counsel for either the prosecution or the defence might, in the course of argument in the absence of the jury, refer to the anticipated answer as part of the argument in favour or against the proposition that, in answering the question, the witness might be giving hearsay evidence. But if no, or no sufficient description of the anticipated evidence is to be found on the record of the trial then issues arise as to how this Court is to determine whether the excluded evidence was compelling evidence. Even if there is an adequate record of the evidence likely to have been given had it not been excluded, how is this Court to assess its reliability and probative value?
3.4 Second, on the facts of this case, the evidence of a confession by Mr. C. had at least the potential to establish the case against him beyond reasonable doubt. If the statement evidence had been admitted, and provided that the defence had not persuaded the jury that they should have any material doubt about its reliability, a confession may have been sufficient to prove guilt. But in many cases, while the excluded evidence may be crucial in connecting an accused to an offence, it may, nonetheless, fall a long way short of being sufficient to prove the prosecution's case by itself. In the language of science, it may be a necessary, but not a sufficient piece of evidence. A simple example will suffice. The excluded evidence may be some item of forensic interest obtained during a raid on a premises where the raid in question may transpire to have been unlawful. All that the evidence obtained as a result of the raid concerned might demonstrate, of itself, is that clothing of the accused found in his home had certain materials on it. That piece of evidence, taken alone, would not establish anything. The prosecution might, however, be able to establish, most probably by other forensic evidence, that the material found on the accused's clothes associated him in some compelling way with the scene of a crime. The evidence might, in those circumstances, be reliable and of high probative value, but only when taken in conjunction with the rest of the prosecution’s case. But it is clear from subsection (14) that the other evidence necessary, in conjunction with the excluded evidence, to permit a jury properly to convict must be evidence "adduced in the proceedings". Therefore, in the example which I have given, does that mean that the prosecution, if it wished to keep alive the prospect of an appeal with prejudice under section 23, would be required to go through the motions of calling a great deal of evidence (after the exclusion of some vital link in the chain of the prosecution’s evidence) so that all of that evidence would have been "adduced" and a conclusion could be reached as to whether that evidence, together with the excluded evidence, would permit a jury to reasonably convict?
3.5 It seems to me that what the Oireachtas most likely had in mind by the inclusion of subsection (14) was to ensure that there could not be a successful appeal under section 23 and a consequent retrial unless there was a reasonable prospect of a successful prosecution on that retrial without additional evidence which had not been tendered at the original trial. It must, however, be open to question as to whether the mechanism adopted in section 23 to achieve that end is effective. However, it also seems to me that, in the circumstances of this case, the potential problems which may well arise in applying section 23 just do not arise. In the course of the argument before the trial judge, on the admissibility issue which is the subject of this appeal, it was accepted on behalf of Mr. C. that the evidence which the prosecution sought to introduce, and to which objection was taken on behalf of Mr. C., involved "admissions … (which) … could reasonably lead to the conviction of (Mr. C.) for the offences which he is charged" [sic]. Thus, on the facts of this case, it appears to have been accepted that the admissions, which the prosecution sought to introduce, were both reliable and of probative value, for if they were not, it is impossible to see how they could reasonably lead to a conviction. Likewise, given that they were admissions, it seems to have been accepted that they could, had they been admitted, have been sufficient, without other evidence, to lead to a conviction.
3.6 In that context, it is important to note the position adopted on behalf of Mr. C. when the matter was relisted for further argument directed towards this issue. Counsel drew attention to the fact that it is this Court which must be satisfied that the evidence excluded is compelling evidence within the definition contained in section 23(14). Counsel also accepted that, in the light of the materials contained in the record of the trial before the Circuit Court, it is open to this Court to be so satisfied. Counsel made the point that the statements made on behalf of Mr. C. during his trial did not create any form of estoppel or otherwise bind Mr. C., still less this Court, to the view that the evidence was compelling in its statutory sense. It is my understanding that counsel for the D.P.P. did not disagree with this view. In my view, both counsel were correct. What is said about evidence at a trial is both admissible and, potentially, important to any consideration which this Court must give as to whether the evidence concerned is "compelling" in the sense used in section 23(14), but it cannot bind either the accused or the Court. If, for example, it was clear that what was said at the trial was wrong, then this Court could not be "satisfied" about the status of the relevant evidence.
3.7 However, in the circumstances of this case, I am satisfied that there is sufficient material available on the record of the trial before the Circuit Court to enable this Court to be satisfied that the evidence is "compelling" in the sense in which that term is used. There has been no suggestion made nor any argument put forward to suggest that counsel's depiction of the confession evidence did not accurately describe it as evidence which would have permitted the jury reasonably to convict. On that basis, it is, at least potentially, reliable, of probative value and sufficient to allow a jury reasonably to convict. It should be emphasised that that does not, of course, mean that a jury would be bound to convict, but rather that it would be open to a jury to convict on the basis of that evidence.
3.8 Given that I have come to that view on the basis of the materials which were before the trial judge, it does not seem to me to be either appropriate or necessary to reach a conclusion on the motion brought on behalf of the D.P.P. seeking to introduce additional evidence. For the reasons which I have already sought to identify, there are, in my view, potential problems surrounding the mechanics of the operation of section 23 which may warrant consideration by the authorities if it is intended to seek to invoke this section again. Those problems focus very much on how it is intended that this Court, which is after all an appellate court, or indeed the Court of Appeal if it is carrying a similar role, is, in practice, to make an assessment of whether excluded evidence meets the test specified in section 23(14). If the legislation is not readdressed then it will be necessary to consider how appellate courts should exercise this jurisdiction in cases where the question of whether the evidence qualifies under subsection (14) may be a lot more difficult than in this particular case. However, having concluded that, in the circumstances of this case, an appeal under section 23 lies, it is necessary to turn to the core substantive issue which is as to whether Kenny was rightly decided.
4. The Exclusionary Rule in D.P.P. v. Kenny
4.1 I should start by indicating my agreement with the analysis of the sequence of cases in this area identified by O'Donnell J. in the course of his judgment in this case. In those circumstances, I do not find it necessary to engage in a detailed review of that jurisprudence. I would confine myself to making a small number of observations.
4.2 First, it seems to me to be clear that the net effect of the decision of this Court in Kenny was to overrule the previous decision of this Court in the People (Attorney General) v. O'Brien  I.R. 142 ("O'Brien"). It is true that this Court did not, in express terms, state that it was overruling O'Brien. Indeed, by adopting the phrase "deliberate and conscious violation" from O'Brien, this Court, in Kenny, might, on a superficial view, be seen to have been simply elaborating on the proper application of O'Brien. However, any true analysis of the situation leads inevitably to a different conclusion.
4.3 It must be recalled that the error of the gardaí which arose in O'Brien stemmed from the fact that the address of the house in Crumlin, to which the relevant warrant related, was misdescribed. But there was no doubt, therefore, that the gardaí in question did not hold a valid warrant to search the house in which the relevant evidence was found. They held a warrant to search a different house on a close-by road with a similar but somewhat different name. The gardaí in question clearly "deliberately and consciously" entered a house in respect of which they did not hold a valid warrant. The house in question was a home with all of the constitutional rights which that attracts. On the facts of O'Brien, there clearly was a deliberate and conscious breach of constitutional rights if the term "deliberate and conscious" is to be applied, as this Court held in Kenny that it should, to the action of those carrying out the search as opposed to the knowledge of those persons that what they were doing was not authorised.
4.4 It is impossible, therefore, to come to any conclusion other than that, if Kenny correctly states the legal position, O'Brien was wrongly decided.
4.5 Indeed, it is convenient to set out the debate which is at the heart of this case by reference to the competing positions identified in both of those cases. While the various courts which dealt with O'Brien do not appear to have considered issues such as carelessness, there can be little doubt but that the facts of O'Brien do betray at least some lack of care on the part of the gardaí involved. It would not have taken a great deal of effort to have checked that the address on the warrant was the same as the address at which the search was about to be carried out. Thus, O'Brien may be seen to be at one end of a spectrum which suggests that evidence should be admitted unless it can be shown that those gathering the evidence in question actually knew that their actions were in breach of constitutional rights. Kenny may be seen to be at the other end of the spectrum, where all that it is necessary to show, so that evidence may be excluded, is that there was a breach of constitutional rights, irrespective of the knowledge or level of care of those involved, save in the highly unusual and exceptional circumstances mentioned in the case law.
4.6 Viewed in that way, it seems to me to be clear that Kenny, in substance, overruled O'Brien, and moved the test to a point at very much the opposite end of the spectrum. The question for this Court is as to whether either O'Brien or Kenny are correct, or, indeed, whether the proper test requires some further refinement by identifying a point along that spectrum which is to be found neither in O'Brien nor Kenny.
4.7 At this point I should also mention that I agree with the analysis set out in the judgment of O'Donnell J. of the international jurisprudence in this area and of its relevance to the issues which this Court has to decide, and I do not find it necessary to add anything to what is said in his judgment in that regard.
4.8 In my view, there are two important and, at least to some extent, potentially competing principles involved. On the one hand is the principle that society, and indeed the victims of crime, are entitled to have an assessment carried out at a criminal trial of the culpability of an accused based on the proper consideration by the decider of fact (be it judge or jury) of all evidence, where that evidence is material to the question of guilt or innocence, is potentially probative of guilt, and is not potentially more prejudicial than probative in the sense in which those terms have come to be used in the jurisprudence. That principle is not, of course, an absolute requirement. However, there is, in my view, a high constitutional value to be attached to ensuring that all potentially relevant evidence, which meets the criteria which I have just sought to define, is considered at a criminal trial.
4.9 In that context, it must be acknowledged that the exclusion of evidence which has the potential to establish guilt on grounds which are unconnected with its probative value can only lead to a risk of the acquittal of guilty persons without any corresponding effect on the likelihood of the conviction of the innocent. Much evidence is excluded on very different grounds. The circumstances in which evidence (such as an admission of guilt) has been obtained may lead to questions as to its reliability. A failure to establish a proper chain of evidence in respect of forensic samples and the results of forensic testing may lead to doubt as to the probative value of the evidence concerned. There are many other circumstances in which the reason for the exclusion of evidence is materially connected to the question of whether it has been shown that the evidence is truly probative or whether the risks of its admission outweigh its probative value.
4.10 But the exclusionary rule is not concerned with such circumstances. The fact that evidence is found in a search of a dwelling house where no proper legal authority for entry has been established does not affect the probative value of the evidence thus found. The extent to which it may provide strong or only supportive evidence of the accused's guilt will depend on the objective, factual circumstances surrounding the evidence in question rather than the legal circumstances in which it came to be discovered or obtained. In this case, we are not, it must be strongly emphasised, dealing with questions of the admissibility of evidence where the question over the admissibility of that evidence stems from issues which may affect its probative value. Rather, we are dealing with questions of admissibility which stem solely from the circumstances in which the evidence was gathered. Thus, the exclusion of such probative evidence can only lead to the risk of the acquittal of guilty persons without any corresponding exclusion or diminution of the risk of the conviction of the innocent.
4.11 However, on the other hand, there is also a significant constitutional value to be attached to the need to ensure that investigative and enforcement agencies (including An Garda Síochána) operate properly within the law. Why do we have elaborate laws concerning arrest, the power to enter premises, questioning and other means of what might be described as non-voluntary evidence gathering? We do so because there is a significant constitutional value in ensuring that there are clear rules which mark the limits of the powers of investigation and enforcement agencies in evidence gathering. Those limits are there to protect us all. There is a high constitutional value in ensuring that those limits are maintained. It follows that there should be consequences, and indeed significant consequences, where those rules are broken.
4.12 But the question which this case throws into stark relief is as to whether those consequences must or should, in some or in all cases, involve the exclusion of probative evidence with the consequent risk that someone in respect of whom there is cogent evidence of guilt may be acquitted.
4.13 If, even in the absence of the potentially contested evidence, there is sufficient evidence to prove the guilt of the accused beyond reasonable doubt then, doubtless, the accused will be convicted and whether the contested evidence was admitted or not will not turn out to have been decisive. Likewise, if, even with the benefit of the contested evidence, there is insufficient evidence to prove guilt to the criminal standard, then the accused will be acquitted. The issue only really arises in any truly material way where the contested evidence gives a real prospect of turning a case which could not be sustained into one where there is sufficient evidence to find the accused guilty. In such cases, where the contested evidence has the potential to make the difference between a finding of guilt or innocence, then it is fair to characterise the question of the admissibility of that evidence as being, likewise, potentially such as makes the difference between a finding of guilt or innocence. If the evidence is of that type, the question which must be asked is whether an accused, in respect of whom there is sufficient probative evidence to establish guilt, must nonetheless be acquitted as a consequence of the fact that some of the evidence necessary to bring the case against him over the threshold to where there is sufficient evidence to prove guilt to the criminal standard was obtained in questionable circumstances. In reality, that is the question which was before this Court in both O'Brien and Kenny.
4.14 In O'Brien, the Court took the view that the accused should nonetheless be convicted even though the evidence was obtained in breach of rights where that breach was not deliberate or conscious in the sense that those who were guilty of the relevant actions did not know that they were committing such a breach. In Kenny, it was held that the accused must nonetheless be acquitted because the act of obtaining the evidence itself was deliberate, even though those involved were not conscious of the fact that they were breaching constitutional rights. In my view, neither position properly balances the legitimate competing interests involved.
4.15 To say that evidence should be admitted in all cases except those where the enforcement and investigation authority concerned actually knew that they were acting in breach of constitutional rights is to place insufficient weight on the need to ensure or at least encourage such agencies to operate within the legal boundaries of their investigative powers. But it seems to me to be equally the case that to require, in substance, that an accused against whom there is sufficient evidence to establish guilt must, in all but the most exceptional circumstances, be acquitted where there has been an inadvertent breach of constitutional rights in the gathering of evidence crucial to the establishment of guilt is to place far too little weight on society's entitlement to secure the proper and legitimate conviction of those guilty of crime and, indeed, the rights of victims to ensure that those who commit crimes against them are brought to justice where there is sufficient probative evidence to establish the guilt of the person concerned to the criminal standard.
4.16 In my judgement, O'Brien does not go far enough but Kenny goes too far. But that does not, of itself, answer the potentially difficult question of precisely how the balance should be struck. The question is difficult not least because it is important that any test be capable of consistent application. Absolute rules have at least the benefit of achieving an easy consistency in their application. Rules which are designed to effect an appropriate balance between two competing, but significant, factors may be more difficult to fashion in a manner which achieves the same level of consistency. However, for the reasons which I have sought to analyse, I am satisfied that it is necessary, despite those difficulties, to determine where the appropriate balance should lie.
4.17 Before going on to address that point, I do not feel that I should leave this aspect of this judgment without dealing with one further argument. That the State, and in particular the courts, has a duty to vindicate the constitutional rights of all cannot be doubted. That there is an obligation to vindicate the rights of those who suffer as a result of the unconstitutional obtaining of evidence cannot, likewise, be doubted. But the real question which arises is as to the manner in which such rights should be vindicated.
4.18 According to Article 40.3 of Bunreacht na hÉireann, the State guarantees in its laws to defend and vindicate the personal rights of citizens "as far as practicable". Furthermore, those rights are to be protected by the State "as best it may" in accordance with Article 40.3.2. It is necessary, therefore, to consider in each case where there has been a breach of constitutional rights as to how the relevant rights should be vindicated. As O'Higgins C.J. noted in Moynihan v. Greensmyth  I.R. 55 at p.71, there may be circumstances in which the State may have to balance its protection of rights against other obligations arising from regard to the common good.
4.19 It does not seem to me to follow that it is necessary, in order to vindicate the right, for example, of integrity of the home, that in all circumstances a party in respect of whom there is sufficient evidence to establish their guilt to the criminal standard must be acquitted if the prosecution case must rely on evidence obtained during a search conducted in breach of that right. Indeed, it is, in passing, worth noting that the constitutional rights concerned may not even be those directly of the accused. Evidence obtained in a search of a home other than that of the accused may nonetheless be obtained in circumstances which breach the constitutional rights of the owner or occupier of the house in question. Is it necessary in those circumstances, in order to vindicate the rights of that home owner, that an accused, whose rights have not in any way been interfered with, is entitled to have his guilt or otherwise assessed without the benefit of potentially probative evidence?
4.20 But even where the rights concerned are those of the accused, does it necessarily follow that the proper way in which those rights are to be vindicated is to acquit the accused of an offence, in respect of which there is sufficient evidence to prove their guilt? I do not think so.
4.21 Of course, it is argued that investigation and enforcement agencies need to be encouraged to operate within the boundaries of their legal entitlements, and that any laxity in the rules concerning the admissibility of evidence obtained outside those boundaries will only encourage the same boundaries to be breached. There is no doubt that there is substance in that argument. There is no doubt that such laxity may, in some cases, lead to a breach of constitutional rights in circumstances which fall short of those where a deliberate and conscious breach can be established in the sense that those involved knew that they were breaching the rights concerned. The need to encourage compliance with important legal boundaries is, itself, a significant constitutional value.
4.22 Indeed, it is clear from the judgment of Finlay C.J. (speaking for the majority in Kenny at pp. 133-134) that the need to provide what was described as a positive encouragement to those in authority formed an important part of the reasoning of the Court. I do not at all disagree with the analysis that such a need exists and that it forms an important part of the constitutional balance which needs to be achieved in this area. It is for that very reason that I am of the view that O'Brien does not go far enough. But to say that, potentially, an accused, in respect of whom there is sufficient evidence to prove guilt to the criminal standard, must go free in virtually all circumstances as a means of enforcement of the boundary of legitimate evidence gathering is, in my view, to go much too far in the other direction. What is required is an appropriate balance which respects the need to encourage enforcement agencies to remain within the boundaries of their legal powers but which does not, even in cases of inadvertence or, indeed, unknown and unknowable difficulties, lead in virtually all cases to the exclusion of otherwise probative evidence and the consequential acquittal of persons in respect of whom there is a sufficient case to prove their guilt beyond reasonable doubt.
4.23 In the same context, I should record that I fully acknowledge the established difficulties which have, unfortunately, been found to have existed in relation to the conduct of some elements of An Garda Síochána. These matters are addressed in the judgment of Hardiman J. Likewise, I acknowledge that there may well have been a tendency, in cases of illegally, as opposed to unconstitutionally, obtained evidence, for courts to tend to exercise their adjudicative role in favour of the admission of such evidence. On that basis, it is suggested that the combination of established police malpractice and a judicial tendency to admit evidence provides an argument in favour of maintaining an almost absolute exclusionary rule. I am afraid I cannot agree.
4.24 The solution to the existence of police malpractice in some cases is not to create an exclusionary rule which applies in all cases. The solution to what might be seen by some as an over-generous attitude of trial judges to the admission of evidence (where a power to admit exists) is not to take away the power to admit in its entirety.
4.25 The proper solution to those problems is to define the law in terms which represent an appropriate balance of the constitutional rights and values at issue, to require trial courts to exercise vigilance to ensure that investigating agencies (such as An Garda Síochána) act in an appropriate fashion and to enable trial judges, having carried out such vigilant scrutiny, to apply a properly defined constitutional balance to the situation which then emerges. There is a further, and in my judgement very important, role to be filled by appellate courts. As O'Donnell J. points out in his judgment in this case, the solution to any general tendency to be over-generous in the admission of evidence, in circumstances where a trial judge has an adjudicative role in respect of that question, is to rely on appellate courts to redress any imbalance which may thus arise. The creation of technical reasons (unconnected with the merits of the case) by which evidence may be excluded or proceedings not progressed deflects from the true enquiry which is as to whether the prosecution case can be proved beyond reasonable doubt. Where those technical reasons impact on that enquiry itself, a very different result may be required. Sometimes a robust response to breaches of the evidence gathering process will be necessary to strike an appropriate balance. But it should not, in my view, be assumed that diverting the criminal process into the side roads of issues not materially connected with guilt or innocence is always an appropriate course to follow. Against that background, I turn to the question of how, in my view, an appropriate balance of the competing constitutional rights and values engaged in this case should be struck.
5 The Balance
5.1 I should start by dealing with what might seem to be something of a preliminary question but which, in my view, nonetheless remains a most important part of the overall approach which should be adopted. In any criminal trial the onus rests on the prosecution to prove guilt. It seems to me that, as part of that overall approach, the onus rests on the prosecution to establish the admissibility of any evidence in respect of whose admissibility a legitimate question is raised. The first part of any proper test must, therefore, state that:-
5.2 Next, it must be recorded that this judgment is concerned with questions relating to the admissibility of evidence arising out of circumstances which do not affect the integrity or probative value of the evidence itself. This judgment is not, therefore, in any way concerned with such questions as might arise where evidence is obtained under oppression or the like. In such cases the circumstances in which the evidence was gathered affects the integrity or probative value of the evidence itself. However, this case is not concerned with such evidence. For the avoidance of doubt, I would, therefore, add to the first part of the proper test the following clarification. "The test which follows is concerned with objections to the admissibility of evidence where the objection relates solely to the circumstances in which the evidence was gathered and does not concern the integrity or probative value of the evidence concerned".
"The onus rests on the prosecution to establish the admissibility of all evidence".
5.3 The next question, which is a connected question, concerns the application of the general rule in circumstances where objection is made to the admissibility of evidence on the grounds that the relevant evidence was obtained in circumstances of unconstitutionality. It seems to me to follow, from the earlier general proposition mentioned above, that the onus remains on the prosecution in such cases to establish the admissibility of the relevant evidence. In particular, it seems to me to follow that the onus rests on the prosecution to establish either:-
5.4 As part of that obligation, it seems to follow that the onus in seeking to justify the admission of evidence taken in unconstitutional circumstances places two separate obligations on the prosecution. The first is to put forward whatever argument or basis it is suggested nonetheless justifies the admission of the relevant evidence. Second, and of equal importance, there must rest on the prosecution an onus to establish any facts necessary to justify such basis. For example, and to the extent that it may be relevant, establishing that those involved in the relevant gathering of evidence were unaware of the unconstitutionality in question is a matter which the prosecution must establish. Likewise, to the extent that any aspect of the general facts surrounding the evidence gathering in question might be relevant to the adjudication of whether evidence is to be admissible, a clear onus rests on the prosecution to establish those facts. While that obligation stems principally from the general obligation which lies on the prosecution, it also seems to me to be strengthened by the fact that the accused will, in the vast majority of cases, have little or no knowledge of the circumstances which led to evidence being obtained in circumstances of unconstitutionality. To place any obligation on the defence to establish such circumstances would be to place an unfair, and in my view an impermissible, burden on the accused.
5.5 Thus, it seems to me that the following must also form part of the test:-
5.6 As part of the general obligation which rests on the prosecution to prove all aspects of a criminal case to the criminal standard (save in those limited circumstances where the law places an onus in a particular regard on the defence) it seems to me to follow that any facts which the prosecution needs to establish in order to discharge the onus on it, which is identified in the previous paragraphs, must be established beyond reasonable doubt. To take any other view would be impermissibly to lessen the burden on the prosecution to prove all matters to the criminal standard.
5.7 Therefore, the test should contain the following element:-
5.8 Next, it seems to me that the proper balance between the competing interests requires that evidence which is taken in conscious and deliberate breach of constitutional rights must be excluded save in the sort of special or exceptional circumstances already identified in the jurisprudence. However, for the purposes of such exclusion, the term "conscious and deliberate" must refer to knowledge of the unconstitutionality of the taking of the relevant evidence rather than referring to the acts concerned. It would truly require exceptional circumstances for the court to admit evidence which is obtained in circumstances where those gathering the evidence knew that they were acting in breach of constitutional rights. Such a situation has to be viewed by any court in the most serious light. In such circumstances, a court is not concerned with merely "encouraging" compliance by enforcement and investigation authorities with the boundaries of their legal powers. Rather, the court is concerned with circumstances where those authorities have taken a calculated decision to go ahead even though they knew that they would be infringing constitutional rights by so doing. The circumstances which could justify a court in admitting evidence taken in those circumstances must remain truly exceptional.
"Any facts relied on by the prosecution to establish any of the matters referred to at (ii) must be established beyond reasonable doubt."
5.9 It is also important to make it clear that the question of whether the taking of evidence is in deliberate and conscious breach of constitutional rights in that sense requires an analysis of the conduct or state of mind not only of any individuals "at the coal face" but also of any other senior official or officials within the relevant enforcement or investigation authority who were involved in a material way in the process. To take but a simple example, a senior investigating garda who is well aware that An Garda Síochána does not have authority to carry out a particular search cannot escape the consequences of a finding of a deliberate and conscious breach of rights simply by procuring that a less experienced or less informed member of the force actually carried out the search in question. In addition, where there is a systemic failure in the sense that senior gardaí are aware of and condone practices which are, to their knowledge, likely to lead to breaches of constitutional rights, then the fact that individual members of An Garda Síochána involved directly in evidence gathering may not have the same knowledge would not justify a finding that there was no deliberate or conscious breach of constitutional rights.
5.10 The test, therefore, requires the following:-
5.11 Next, it seems to me to follow that, where evidence is taken in circumstances of unconstitutionality, but where the prosecution establishes that same was not conscious and deliberate in the sense already identified, the evidence should be admitted if the prosecution can also establish that the unconstitutionality concerned arose out of circumstances of inadvertence or by reason of developments in the law which occurred after the time when the relevant evidence was gathered.
"Where evidence is taken in deliberate and conscious violation of constitutional rights then the evidence should be excluded save in those exceptional circumstances considered in the existing jurisprudence. In this context, deliberate and conscious refers to knowledge of the unconstitutionality of the taking of the relevant evidence rather than applying to the acts concerned. The assessment as to whether evidence was taken in deliberate and conscious violation of constitutional rights requires an analysis of the conduct and state of mind not only of the individual who actually gathered the evidence concerned but also of any other senior official or officials within the investigating or enforcement authority concerned who are involved either in that decision or in decisions of that type generally or in putting in place policies concerning evidence gathering of the type concerned."
5.12 I consider that including an exception of this type properly meets the balance of interests engaged in this case. It is illustrative to look at the facts before us. As a result of a subsequent decision of the courts, it became clear that a particular form of warrant was invalid. That legal fact was not known at the time of the evidence gathering at issue in this case. It is true that some doubts had been expressed over the constitutional validity of the relevant measure, but it remained on the statute book and enjoyed the presumption of constitutionality. In what way could it be said that it would encourage enforcement and investigation authorities to remain within the boundaries of their legal power if evidence is to be excluded by reference to legal decisions not even taken at the time when the power in question was exercised?
5.13 It seems to me that, likewise, inadvertence, such as that which was present in O'Brien, should not lead to the exclusion of otherwise probative evidence. It is true that imposing a rule of almost absolute exclusion (which rules out evidence even in cases of inadvertent breach of constitutional rights) might act as a somewhat greater encouragement to authorities towards strict compliance with their obligations. However, the price to be paid for that exceptionally high level of encouragement involves an inappropriate balancing of the interests concerned. On the other hand, if, short of a deliberate and conscious act, evidence is taken in circumstances of recklessness or gross negligence, then a different balancing exercise arises, for it is important that those involved in investigation and enforcement know that they cannot expect that reckless or grossly negligent actions will not have serious consequences for evidence gathering. To rule otherwise would be to place the level of encouragement to compliance at too low a level.
5.14 It is important to make clear, in that context, that the term "inadvertent" cannot be said to include a case where any relevant person acted in a manner which was reckless or grossly negligent. There is one sense in which the word "inadvertent" simply means that a person did not advert to the problem. On that basis, a person who, even though grossly negligent, might not actually have "adverted" to the fact that they were acting in breach of constitutional rights might, nonetheless, be said to have acted inadvertently. It is important to emphasise that the term "inadvertent", in the sense in which it is used in this judgment, could not encompass such actions.
5.15 On the other side of the equation, it does seem clear that inadvertence can include at least some circumstances which might be regarded as negligent in the broadest sense of that term. A professional person who, for example, fails to notice some material aspect of an issue on which they are to advise or in respect of which they are to act might well be said to have acted inadvertently but might, nonetheless, be found liable in negligence.
5.16 It might be argued that permitting the admission of evidence taken in circumstances of inadvertent breach could place a premium on ignorance. Evidence obtained in conscious and deliberate violation of constitutional rights, in the sense in which I have used that term, will be excluded. It might be said that it is more easily determined that the knowledgeable were aware of what they were doing compared with those who may be ignorant of the relevant law. However, it is clear from the sense in which I have suggested that the term "inadvertence" should be used that investigative agencies cannot hide behind an unacceptable lack of knowledge appropriate to their task for the purposes of pleading inadvertence. It does not, therefore, seem to me that the test which I propose, when properly analysed, gives any comfort to those who might seek to rely on exaggerated ignorance of the law to escape a ruling in favour of the admission of evidence taken in breach of constitutional rights.
5.17 An exclusionary rule which permits the admission of evidence obtained in circumstances of either inadvertence or where there are subsequent legal developments is sufficient to resolve this case. Doubtless the precise parameters of the point at which, in practice, inadvertence may be said to stop being an appropriate characterisation of events will be defined by further case law.
5.18 Before leaving this aspect of the test I would add one further observation. It is suggested that, in formulating the test in this way, inadvertence is elevated to the status of providing a lawful excuse for unconstitutional action. I cannot, with respect, agree that such is an appropriate characterisation. As O'Donnell J. points out, the fact that there may have been a breach of constitutional rights by inadvertence does not excuse that breach. A claim in trespass, for example, would not fail simply because an enforcement officer entered onto premises without legal authority in circumstances where the officer concerned was unaware, due to inadvertence, of the absence of such proper authority. The trespass would not be excused by any inadvertence. Many other similar examples could be given.
5.19 The issue here, however, is not as to whether the actions of the relevant investigating authorities are so excused. They are not. Rather, the issue is as to whether otherwise cogent and probative evidence is to be excluded from the court's consideration because of the manner in which it was gathered. To say that there may be circumstances where such evidence can properly be admitted, even though there may have been a breach of rights in the manner in which the evidence was gathered, is not to excuse or, as it is put, lawfully excuse, the conduct in question. Any sanction applying in the civil, or indeed, the criminal law for that breach will apply. But it is an entirely different question to consider whether evidence must be thereby excluded. As I suggested earlier, it is, in my judgement, to go much too far to suggest that a person against whom there is cogent evidence of guilt must necessarily escape conviction solely because there was an inadvertent breach of rights in the gathering of some essential piece of evidence which occurred in a way which does not affect either the integrity or the probative value of the evidence concerned. The focus of the trial of a person whose guilt or innocence might be affected by the evidence concerned is on whether that person is guilty or innocent of the offence as charged. The focus of that trial is not, or at least is not primarily, on whether otherwise cogent and probative evidence was properly gathered. To admit evidence in certain circumstances, even though it was not properly gathered, does not excuse or lawfully excuse any breach of rights concerned. It simply recognises that the evidence remains, notwithstanding the manner in which it was gathered, probative and cogent.
5.20 It seems to me to follow, therefore, that the test should include the following:-
5.21 There is one further refinement which, in my view, ought be added. It is important to distinguish between evidence gathering which occurs in circumstances where same could not have been constitutional in any circumstances, on the one hand, and evidence gathering which was capable of being lawful and would have been lawful were it not for the absence of some appropriate form of valid authorisation specific to the facts of the case in question. In that latter category, cases would also arise where there was an authorisation, but where there was some defect in the authorisation concerned. In that context, there is a difference between prosecuting authorities being able to rely, on the one hand, on evidence, the gathering of which was not authorised, but which could have been authorised, and where the absence, inaccuracy or invalidity of or in the relevant authorisation was not adverted to, and, on the other hand, evidence gathering which could never have been authorised at all.
"Where evidence is taken in circumstances of unconstitutionality but where the prosecution establishes that same was not conscious and deliberate in the sense previously appearing, then a presumption against the admission of the relevant evidence arises. Such evidence should be admitted where the prosecution establishes that the evidence was obtained in circumstances where any breach of rights was due to inadvertence or derives from subsequent legal developments."
5.22 A final element of the test should, therefore, provide the following:-
5.23 Before concluding this aspect of this judgment I would propose to make some final observations.
"Evidence which is obtained or gathered in circumstances where same could not have been constitutionally obtained or gathered should not be admitted even if those involved in the relevant evidence gathering were unaware due to inadvertence of the absence of authority."
6 Some Final Observations
6.1 It bears noting that, while a significant amount of the recent focus in the jurisprudence in this area has concerned evidence obtained in circumstances of unconstitutionality, evidence obtained illegally is also a matter with which the courts should be significantly concerned. It is true that there is a particular onus on the courts to discourage unconstitutionality having regard to the constitutional imperative placed on the courts to uphold the Constitution and to vindicate constitutional rights. However, there is also an obligation on the courts to uphold the law and to discourage illegality.
6.2 It should not, therefore, be taken that evidence obtained in circumstances of illegality should readily be admitted. Where the absence of legality arises in circumstances properly described as reckless or grossly negligent, then the relevant evidence should be excluded even if the illegality concerned does not result in a breach of constitutional rights.
6.3 It does, however, seem to me that it would be appropriate for a court charged with deciding on the admissibility or otherwise of evidence in a particular case to have regard, in assessing whether the impugned actions of those who gathered the evidence in question were inadvertent, to the status of the rights which were shown to have been breached. Where evidence gathering might, in the absence of appropriate authority, give rise to a breach of constitutional, as opposed to legal, rights, then there is a greater obligation on those involved in gathering the evidence in question to ensure that they have proper legal authority for what they are doing. Given that greater obligation, a court might well more readily find fault beyond inadvertence in relation to a breach of constitutional rights rather then legal rights, for the greater the obligation of care, the easier it will be to determine that an absence of care was more severe. That being said, it must nonetheless remain the case that, where an issue as to the admissibility of evidence obtained or gathered in circumstances of illegality arises, the court must carefully scrutinise all the circumstances of the case to determine whether it is appropriate to admit the relevant evidence.
6.4 The principles which I have sought to identify seem to me to be appropriate in all cases where there is a challenge to the admissibility of evidence on a basis connected with the manner in which the evidence was gathered or obtained as opposed to questions relating to the probative value of the evidence concerned. Those principles are, therefore, necessarily general in their terms. The precise application of those principles will need to be developed on a case by case basis. For example, and at the level of greatest generality, issues of this type most frequently arise in two different sets of circumstances. The first set of circumstances are cases, such as this, where evidence is gathered on foot of a search warrant or other statutory search authority, and where it is established that there was some problem with the relevant authority so that the search was not authorised. The other main category of cases concerns circumstances where a problem arises concerning the lawfulness of the custody of a suspect who is being questioned. In those latter cases, it is important to emphasise that this judgment is, as has been pointed out on a number of occasions, concerned with objection to the admissibility of evidence which is based simply on an alleged unconstitutionality in respect of the evidence gathering, rather than, as sometimes arises in custody cases, issues as to whether the relevant evidence can truly be regarded as appropriately probative having regard to the circumstances in which it was obtained.
6.5 Obviously, the practical application of these general principles may differ somewhat as and between warrant or search authorisation cases, on the one hand, and custody cases on the other. As already noted, the precise application of the general principles is a matter which will need to be developed on a case by case basis.
7. The Test
7.1 For the reasons which I have sought to analyse in section 5 of this judgment, it seems to me that the elements of the test to be applied to the question of exclusion of evidence taken in circumstances of illegality or unconstitutionality are those identified in that section of the judgment.
7.2 In summary, the elements of the test are as follows:-
7.3 In my view, the application of that test should also be informed by the matters identified in sections 4 and 5 of this judgment. It is next necessary to consider the application of that test to the facts of this case.
(i) The onus rests on the prosecution to establish the admissibility of all evidence. The test which follows is concerned with objections to the admissibility of evidence where the objection relates solely to the circumstances in which the evidence was gathered and does not concern the integrity or probative value of the evidence concerned.
(ii) Where objection is taken to the admissibility of evidence on the grounds that it was taken in circumstances of unconstitutionality, the onus remains on the prosecution to establish either:-
(a) that the evidence was not gathered in circumstances of unconstitutionality; or
(b) that, if it was, it remains appropriate for the Court to nonetheless admit the evidence.
The onus in seeking to justify the admission of evidence taken in unconstitutional circumstances places on the prosecution an obligation to explain the basis on which it is said that the evidence should, nonetheless, be admitted AND ALSO to establish any facts necessary to justify such a basis.
(iii) Any facts relied on by the prosecution to establish any of the matters referred to at (ii) must be established beyond reasonable doubt.
(iv) Where evidence is taken in deliberate and conscious violation of constitutional rights then the evidence should be excluded save in those exceptional circumstances considered in the existing jurisprudence. In this context deliberate and conscious refers to knowledge of the unconstitutionality of the taking of the relevant evidence rather than applying to the acts concerned. The assessment as to whether evidence was taken in deliberate and conscious violation of constitutional rights requires an analysis of the conduct or state of mind not only of the individual who actually gathered the evidence concerned but also any other senior official or officials within the investigating or enforcement authority concerned who is involved either in that decision or in decisions of that type generally or in putting in place policies concerning evidence gathering of the type concerned.
(v) Where evidence is taken in circumstances of unconstitutionality but where the prosecution establishes that same was not conscious and deliberate in the sense previously appearing, then a presumption against the admission of the relevant evidence arises. Such evidence should be admitted where the prosecution establishes that the evidence was obtained in circumstances where any breach of rights was due to inadvertence or derives from subsequent legal developments.
(vi) Evidence which is obtained or gathered in circumstances where same could not have been constitutionally obtained or gathered should not be admitted even if those involved in the relevant evidence gathering were unaware due to inadvertence of the absence of authority.
8 Application to the Facts of this Case
8.1 As already noted, the potential issue concerning the admissibility of the relevant evidence in this case concerned the validity of a warrant of the type found invalid by this Court in D.P.P. v. Damache  2 I.R. 266. At the time when the evidence in question was gathered, Damache had not been decided. The warrant was, therefore, issued on foot of a statutory provision which enjoyed the presumption of constitutionality and which had not, at the relevant time, been the subject of any judicial determination concerning its inconsistency with the Constitution. It is possible that different considerations might well arise in a case where there had been a relevant determination of the High Court (or the Court of Appeal) which would, if correct, render the relevant warrant invalid. Even where such a determination was under appeal it would represent the law as understood at the time in question.
8.2 It is true that there had been some suggestions made in legal debate over the years which might have questioned the validity of the type of warrant used in this case and also in Damache. However, it does not seem to me that such debate can influence the proper approach to an assessment of the circumstances in which the warrant in this case was granted and executed. The substance of the factual underlay to this case is that the evidence in question was gathered on foot of a warrant which was prima facie valid on the basis of the law as it stood when that warrant was issued, and where the warrant was issued in furtherance of a statutory provision which enjoyed the presumption of constitutionality. In those circumstances, it seems to me that this case comes clearly within the category of case where the evidence should properly be admitted on the basis of the test which I propose. On that basis, it seems to me that, while the trial judge was, of course, bound by Kenny, her decision to exclude the evidence in question was necessarily erroneous in the sense in which that term is used in section 23. I would, therefore, so find.
8.3 In the light of that finding, it is necessary to return to the structure of an appeal under section 23. Subsection (11) allows this Court to quash an acquittal and order a retrial if satisfied that the requirements of subsection (3)(a) or (3)(b) are met, and that "having regard to the matters referred to in subsection (12), it is, in all the circumstances, in the interests of justice to do so". The subsection goes on to specify that, if this Court is not satisfied of both of those matters, the court should affirm the acquittal.
8.4 For the reasons already identified, I am satisfied that the requirements of subsection (3)(a) are met in that I am satisfied that compelling evidence was erroneously excluded as a result of a ruling made by the Court during the course of a trial. While that is a necessary condition to the reversal of an acquittal, it is not sufficient to that end. A final decision on whether the appeal should be allowed must, therefore, await a determination as to whether it is in the interests of justice, having regard to the matters specified in subsection (12), to quash the acquittal of Mr. C. As a consideration of those matters has been left over, it is not, therefore, possible at this stage to determine whether the appeal should be allowed or dismissed.
9.1 For the reasons analysed earlier in this judgment, I have come to the view that an appeal in relation to the exclusion of evidence can properly be brought under section 23, notwithstanding the fact that the trial judge who excluded the evidence in question properly applied existing case law by which that judge was bound. It seems to me that, where this Court concludes that such existing case law is, itself, wrong, then it follows that the exclusion of evidence based on such case law is also wrong and, therefore, "erroneous" provided that, of course, on the basis of the application of what this Court now determines to be the appropriate test, the evidence should have been admitted.
9.2 In addition, for the reasons set out earlier in this judgment, I am satisfied that, on the facts of this case, it is appropriate to conclude that the evidence excluded by the trial judge is "compelling evidence" in the specific sense in which that term is used and defined in section 23. In those circumstances, I am satisfied that the appeal brought by the D.P.P. in this case comes within the scope of section 23 as properly interpreted.
9.3 For the reasons analysed, most particularly in section 4 of this judgment, I am satisfied that both Kenny and O'Brien fail adequately to balance the competing constitutional rights involved. I set out, in sections 5 and 7 of the judgment, what seems to me to be the appropriate approach. Applying that approach to the facts of this case, I am satisfied, for the reasons set out in section 8 of this judgment, that the evidence which is the subject matter of this appeal was erroneously excluded by the trial judge in the sense in which that term is used in section 23.
9.4 It follows that the first leg of the requirement of a successful appeal by the D.P.P. under section 23 has been met. As noted earlier in the course of this judgment, it was common case that the question of whether there should, in those circumstances, be a retrial was left over until after the substantive issues were determined. I would, therefore, propose that the matter should be relisted to hear counsel on the question of whether Mr. C.'s acquittal should be quashed and a retrial ordered, or whether his acquittal should be affirmed on the basis that it would not be in the interests of justice, in the light of the maters specified in section 23(12), to order a retrial.