94 I have had the advantage in this application of reading, in draft, the separate
reasons for judgment of the Chief Justice and of Nettle J.A. I do not differ in any material respect from either. I add that which follows only because this is an application with special features following a trial with special difficulties; and a third perspective may be helpful.
95 To a community seeking justice following the commission of an horrendous crime, the conviction of someone for that crime will generally be a source of satisfaction. That satisfaction might not be greatly affected by concern that, in their desire to bring the perpetrator to justice, the investigative techniques adopted by the police may perhaps have been faulty. Nor might the public be keenly appreciative of the truth that a mistaken guilty verdict is not only a grave injustice to an innocent person, but most often also results in the real perpetrator escaping any punishment. But no civilised society could live happily for long with a conviction which was based upon no surer foundation than the proposition that, the accused having committed crimes in the past, even crimes of a particular kind, he or she was likely to have committed the similar crime for which he or she was most recently tried. Experience and the application of commonsense both point to the conclusion that an inference of present guilt, such as to satisfy the required standard of proof (which, of course, is beyond reasonable doubt) cannot generally be drawn on the basis of a past criminal record. It is not simply that knowledge of the criminal record might so prejudice the mind of the tribunal of fact that speculation would replace the process of logical deduction without which inferences cannot properly be drawn. It is also that the presumption of innocence would lose a significant portion of its content. Moreover, a past record is not only a very unreliable indicator of later behaviour, but if it were available as evidence, the prosecuting authorities might be tempted to put it to unjust use.
96 On the other hand, a particular crime might be committed in such a strikingly similar way to another that the signature of a particular perpetrator can readily be seen in both. It would in those circumstances defy commonsense to remove from a court's consideration of the accused's guilt on a charge relating to one of those crimes a comparison between that crime and the other, similar, offence of which the accused had already been found guilty.
97 Even so, the admission of "similar fact" or "propensity" or "tendency" evidence[97] is fraught with the danger that it will result in injustice. Every trial judge, faced with the necessity to decide whether, and if so in what circumstances, propensity evidence should be adduced, has the grave responsibility of ensuring that its prejudicial effect is not, and will not become, greater than its probative value. On occasions, the imbalance will be such that the decision is relatively easy. On others, the opposite will be true. In the latter circumstances, the correctness of the decision to admit or not to admit may depend on the means open to the judge to minimise or eliminate the risk of injustice, and on his or her success in putting them into effect. Also important may be the relationship between those aspects of the case to which the propensity evidence directly relates and those to which it has no relevance save for its tendency prejudicially to infect the jury's consideration of them.
98 This case provides an unusually powerful illustration of these points. The applicant was tried for the murder, committed on 4 October 1997, of a prostitute, Ms Margaret Maher. After her death, her body had been horribly mutilated. As the Crown initially submitted, the propensity evidence admissible at the trial extended not merely to evidence of the applicant's mutilation on 19 April 1999 (some 18 months after the death of Ms Maher) of the dead body of his treating psychologist, a woman named Nicole Patterson, but also of his infliction on her of the multiple stab wounds from which she died. This evidence was prejudicial in the extreme. It was admitted nevertheless, but only as tending to prove that the man who mutilated the body of Ms Patterson was also the man who mutilated the body of Ms Maher - and that that man was the applicant. It was not admitted to prove that the applicant murdered Ms Maher. It is with this distinction that this application is principally concerned. The measures conceived by the trial judge, Kaye J, to ensure that the distinction was preserved, and his success in the implementation of those measures, together justify the hope that this case will provide useful guidance for trial judges in the future.
99 The relevant facts are comprehensively set out in the judgment of the Chief Justice, and I do not need to repeat them. For my purposes it is only necessary to note that, at trial, the Crown case was that Ms Maher was murdered, and that one person, the applicant, was her killer. Three issues were hotly contested, although if the first was resolved in the negative the remaining two would disappear; and if the second was likewise resolved, the last would similarly fall away. The first contested issue was whether a person caused the death of Ms Maher. If the jury accepted that the prosecution case on this point had been made good to their satisfaction beyond reasonable doubt, then the second issue had to be addressed: was her death intended by that person? If the answer to this was yes, then the question of identity arose.
100 It is at this point that the propensity evidence assumes its importance. In the absence of any evidence that the applicant mutilated the body of Nicole Patterson, her death would have been irrelevant to the applicant's trial for the murder of Ms Maher. The two women died in quite different circumstance. It was what happened immediately afterwards that was strikingly similar.
101 As a matter of reality, the applicant's best hope was that the prosecution would fall at the first hurdle. Dr Matthew Lynch, the pathologist who conducted the post mortem examination of Margaret Maher, found a number of injuries to the body of the dead woman. These are described in the judgment of Nettle J.A. None of them pointed directly to the cause of death. The most significant was a lineal area of petechial haemorrhage on the right lateral neck which, on dissection, was seen to be associated with a minor haemorrhage within the muscles adjacent to the thyroid cartilage. This was consistent with Ms Maher having been the victim of compression of the neck; and it was possible that that compression was a cause, or indeed the cause, of her death. But there were two other possible causes: drug toxicity and heart failure. Dr Lynch could elevate none of the three above the status of possibilities. While the evidence remained at that point, no jury could convict on a charge of murder.
102 But there was, of course, more. The other, vital, piece of evidence was the fact of the mutilation; and this was evidence the relevant significance of which it was for the jury, not Dr Lynch, to assess. If the trial was to be fair, that assessment had to be effected carefully and rationally. It did not necessarily follow that, because Ms Maher's body had been mutilated after death, she had been murdered. The possibility remained that the mutilator was not with her when she died. It was also possible that, although in her presence, he (we may, for present purposes, assume it was a male) in no way contributed to her death. She was a drug-dependent prostitute in very poor health, including in the functioning of her cardiac system. Death by natural causes might have occurred at any time. Her post-mortem attacker may have been a client. Clients of prostitutes are not necessarily lovely people. Expectations disappointed by the sudden and unanticipated death of the service provider might induce in those clients unlovely responses.
103 This, of course, is no more than supposition. But it may have been enough to create a reasonable doubt in the jury's mind. A further possibility was that the mutilator's actions caused or contributed to Ms Maher's death, but that he did not intend either to kill her or to cause her really serious injury. A final possibility was that her mutilator was also her murderer. He was certainly violently disposed towards her after her death; and, that being so, it was of course possible to infer that his disposition arose during her life.
104 A "no case" submission was put to his Honour. The judge was in my opinion entitled, if not bound, to reject it, which he did. Nevertheless, if one puts the Patterson evidence to one side, as the jury were bound to do when considering whether a person caused the death of Ms Maher and, if so, whether that person intended to kill her, the prosecution case was not so strong as to be overwhelming. On the strictly limited evidence upon which, as the judge correctly instructed them, the members of the jury were constrained to base their conclusion on these points (that is, putting entirely to one side the evidence relating to Nicole Patterson), they might properly have returned a verdict of not guilty on the ground that one or other of those elements of the prosecution case had not been made out to the requisite standard.
105 It is certainly true that the jury were not entitled simply to assume that Ms Maher was murdered. It follows as of course that it was equally impermissible for them to assume that a particular person was the murderer. They were similarly not entitled to conclude that the applicant, being the person that he was, must be guilty of the crime. It was their duty to examine the evidence - but only the relevant evidence - with scrupulous care before deciding whether they were satisfied beyond reasonable doubt that Ms Maher's death was attributable to an unlawful act; and, if so, who was responsible.
106 Acceptance by the trial judge of the Crown's submissions on the use to be made of the propensity evidence would have prevented the jury giving effect to this duty. The Crown initially sought to persuade the judge that the propensity evidence was all of a piece. Ms Patterson had been murdered and then mutilated. Ms Maher had suffered the same fate. The applicant was on trial for the latter's murder. The propensity evidence was relevant in his trial. The Crown submitted that it should be used by the jury as evidence of the applicant's role not only as the mutilator but also as the murderer.
107 This approach was flawed. It assumed that which had to be proved: that Ms Maher was murdered. It also glossed over the reality that Ms Patterson met her death in strikingly different circumstance to Ms Maher. The differences were many. The most significant was that the former suffered multiple stab wounds from which she died, whereas Ms Maher's injuries were relatively slight; and her attacker - if she was attacked - did not use a knife. The striking similarity in the post-mortem dealings with each body could not properly be extended so as to overwhelm the differences in the manner of the two deaths.
108 His Honour was at pains to make this clear. He correctly informed the jury that they should not consider the "Patterson" evidence at all, but rather put it out of their minds, unless and until they were satisfied beyond reasonable doubt that Ms Maher had died at the hands of someone who intended to kill her, or cause her really serious injury, or (since a verdict of manslaughter was open) who unlawfully committed an act which (as the wrongdoer ought to have realised) exposed Ms Maher to an appreciable risk of really serious injury.
109 When the members of the jury retired to consider their verdict, the Patterson evidence was nevertheless before them. It could not but have made a deep impression. They could not have divorced themselves from it. And its prejudicial effect would have been at its most powerful when the jury came to decide whether they were satisfied beyond reasonable doubt that Ms Maher's death was caused by a person and, if so, whether that person intended to kill her. This was the weakest aspect of the case against the applicant. It would have been tempting for the jury to throw aside a doubt they might otherwise have had on the basis that, if they were satisfied that the applicant murdered Ms Patterson, then they could accept without rigorous analysis that he also murdered Ms Maher. He was that kind of man.
110 Thus, when deciding whether the prejudicial effect of the evidence outweighed its probative value, and therefore whether or not the evidence should be admitted, it was to this aspect of the case that attention had most carefully to be drawn.
111 In my opinion, his Honour made the right decision for the right reasons. Under s.398A of the Crimes Act 1958, propensity evidence is admissible in a criminal trial if the court considers that in all the circumstances it is just to admit it despite any prejudicial effect it may have on the accused. One measure of such effect is the nature of the propensity evidence itself. But it is not the only measure. Another is the likelihood that any prejudice will or will not be sufficiently counteracted by the directions of the trial judge. It may be that, in some instances, neutralisation, or something sufficiently close to it, will not be the result, no matter how careful the directions might be. In others, careful directions will suffice. The applicant submitted (Ground 1A in his application for leave to appeal) that, in this case, the risk could only be avoided if the jury were not exposed to it at all: otherwise, the jury would not - perhaps could not - put out of their minds the highly prejudicial evidence concerning Nicole Patterson upon the correct or incorrect admission of which this appeal turns. Put at its highest, the argument is that, with that evidence influencing their deliberations, the jury gave an affirmative answer to the question whether Ms Maher was murdered. Had they not been so influenced, a real possibility is that the answer would have been in the negative. At the very least, the trial judge's directions were not good enough (Ground 1B); and, on that basis, leave to appeal should be granted.
112 I agree that the propensity evidence was prejudicial. But I do not agree that the directions given to the jury by the trial judge were inadequate. On the contrary, his Honour's directions were in my opinion clear, accurate and sufficient. It was necessary that the jury be told that, before they could turn to the identity of Ms Maher's killer, they must be satisfied to the criminal standard that Ms Maher had died at the hands of some person, and that he or she intended to kill her or cause her really serious injury. The jury were so instructed. The jury were also told, as was necessary, that the evidence concerning Ms Patterson was relevant only on the question of identity, and on that point all the dissimilarities, as well as all the similarities, in the two post-mortem excisions, including the evidence about the cutting of the clothes, were relevant. The instructions given to them by the trial judge included a clear warning that they must not accept that the person who mutilated Ms Patterson and he who mutilated Ms Maher were one and the same, and that the applicant was that person, unless they were satisfied beyond reasonable doubt that the similarities when seen against the dissimilarities left no other conclusion open. They were instructed not to draw any conclusions from the circumstances in which Ms Patterson met her death, circumstances that had to be revealed to them because they were inextricably intertwined with the evidence of the latter's mutilation.
113 In my opinion, Kaye J was justified in concluding that these directions could (and therefore, despite any adverse effect of media publicity, would) be followed by the jury, and that in all the circumstances it was just to admit the propensity evidence despite its prejudicial effect. Indeed, this case is a good example, it seems to me, of the truth of the proposition that, given the probative value of some propensity evidence, it may be just to admit it despite its very prejudicial effect. It will always be necessary to ensure that the latter is dissipated as much as is possible by appropriate directions from the trial judge to the jury.
114 The similarities and differences between the post-mortem fate of Ms Patterson and that of Ms Maher have been described in the judgment of Nettle, J.A. I need not recount them. Once the jury were satisfied that Ms Maher was murdered, the question of the identity of the murderer became the sole remaining issue. I agree with his Honour that the inference that the man who mutilated the body of Nicole Patterson was the same person who had earlier mutilated the body of Margaret Maher is supported by the underlying unity in the extraordinary nature of the method and incidents surrounding the two cases. Thus supported, the inference becomes so strong as to be capable of removing any reasonable doubt. It already having been established that Ms Maher was murdered, the conclusion that her mutilator was also her murderer was then almost inevitable.
115 The applicant submitted that in any event the propensity evidence should have been excluded by the proper application of what has become known as the Christie discretion. I agree with what the Chief Justice has written on this point. I also agree with Nettle J.A. The argument that there remains room for that discretion in the face of s.398A could only be attractive, if at all, in very special circumstances. They do not obtain here.
116 I am in agreement with the separate judgements of my colleagues on Grounds 2 and 4 of appeal. Like Nettle J.A., I also am in agreement with the conclusion reached by the Chief Justice. I would refuse the application for leave to appeal.