Aytugrul v The Queen [2012] HCA 15 | Case summary

Aytugrul v The Queen [2012] HCA 15 | Case summary | Zoe

FRENCH CJ, HAYNE, CRENNAN AND BELL JJ. The appellant was tried in the Supreme Court of New South Wales for murder. The deceased and the appellant had been in a relationship but that relationship had ended more than two years before the deceased was stabbed to death. The prosecution case at trial was circumstantial. The prosecution alleged that the motive for the killing came from the failure of the appellant's relationship with the deceased and her having formed a relationship with another man. In order to establish motive, the prosecution relied on evidence that about five months before the deceased was killed the appellant had published a poem in the Turkish Weekly News declaring that he could not give up his love for the deceased. (Both the appellant and the deceased were of Turkish origins.) The prosecution further relied on evidence which it was said showed that the appellant had stalked and harassed the deceased for some months before her death.
This appeal concerns the admissibility of some evidence led at trial about a DNA analysis. A hair found on the deceased's thumbnail had been subjected to mitochondrial DNA testing. The results of that testing showed two things: first, that the appellant could have been the donor of the hair and, second, how common the DNA profile found in the hair was in the community. This second aspect of the results was expressed in evidence both as a frequency ratio[1] and as an exclusion percentage. The expert who had conducted the test gave evidence to the effect that one in 1,600 people in the general population (which is to say the whole world) would be expected to share the DNA profile that was found in the hair (a frequency ratio) and that 99.9 per cent of people would not be expected to have a DNA profile matching that of the hair (an exclusion percentage).
It is alleged that the evidence the witness gave in the form of an exclusion percentage was not admissible.
The appellant appealed to the Court of Criminal Appeal against his conviction on grounds that included the ground that "a miscarriage of justice occurred because of the prejudicial way in which DNA evidence was expressed to the jury". The Court of Criminal Appeal, by majority (Simpson and Fullerton JJ, McClellan CJ at CL dissenting), dismissed[2] the appellant's appeal.
By special leave, the appellant now appeals to this Court alleging that the Court of Criminal Appeal should have held that the trial judge had erred "in admitting statistical evidence expressed in exclusion percentage terms". The appellant submitted, in effect, that s 137[3] of the Evidence Act 1995 (NSW) required exclusion of evidence which expressed the results of the DNA testing as an exclusion percentage and further submitted that, if that were not so, the only proper exercise of the general discretion to exclude evidence given by s 135[4] of the Evidence Act would have seen the evidence excluded.
The appellant did not demonstrate that the evidence given at the trial which expressed results of the DNA testing as an exclusion percentage was evidence the probative value of which was outweighed by the danger of unfair prejudice to the appellant. Neither s 137 nor s 135 of the Evidence Act was engaged. The appeal should be dismissed.

The prosecution called two witnesses to give expert evidence about mitochondrial DNA analysis of the hair that had been found under the deceased's thumbnail. The defence called its own expert on the subject. All three witnesses agreed that the appellant could not be excluded as having been the donor of the hair that had been found, but their evidence differed as to the weight that could be given to this conclusion.
One of the two experts called by the prosecution, Ms Gina Pineda, Associate Laboratory Director and Technical Leader of a United States DNA laboratory company, had supplied a written report of the results of mitochondrial DNA testing by the company of the hair recovered from the deceased and its comparison with the results of testing of a sample of blood taken from the deceased and a sample of saliva taken from the appellant. The report expressed the conclusions that the deceased and all her maternal relatives were excluded as the donor of the hair but that the appellant and his maternal relatives were not excluded. Using a database that Ms Pineda later identified and described in her oral evidence, the report said that the mitochondrial DNA sequence identified in the hair sample had been observed "0 times[[5]] in 4839 individuals of various population groups (99.9% excluded)".
In the light of the report Ms Pineda had supplied, trial counsel for the appellant objected to reception of any of Ms Pineda's evidence other than her evidence that the appellant could not be excluded as the donor of the hair. As initially framed, the objection, though mentioning both ss 135 and 137 of the Evidence Act, was founded not on the point made in this Court but on a challenge to the sufficiency of the database relied on by Ms Pineda as a foundation for expressing her further opinions. After evidence was taken on the voir dire, trial counsel did accept, at one point in her submissions, that the witness could express the opinion that one in 1,600 persons could be expected to have the same DNA profile but objected to the witness expressing the same result as an exclusion percentage of 99.9 per cent "[b]ecause it has a connotation that is very different to the reality". But following an adjournment, trial counsel for the appellant pressed the larger and wider objection that the witness could give no evidence extrapolating from observing the DNA sequence once in a database of 4,839 individuals to frequency of occurrence (or exclusion percentage) in the general population because the database used by the witness as the foundation for her opinion was not shown to be a database that would yield relevant results. Only passing reference was made again to the witness giving evidence of an exclusion percentage, the chief thrust of the argument being that Ms Pineda should not be permitted to give evidence of either a frequency ratio of one in 1,600 or an exclusion percentage of 99.9 per cent.
This being the state of argument about the admissibility of the evidence, it is unsurprising that the trial judge (R A Hulme AJ) delivered reasons which dealt only with the objection to reception of any evidence from Ms Pineda which extrapolated from the observations made by comparison with the database used to a frequency ratio of one in 1,600 or an exclusion percentage of 99.9 per cent. The trial judge overruled the objection holding, in effect, that the alleged insufficiency of the database relied on by Ms Pineda was not a basis for rejecting the evidence she would give of her opinions. No separate consideration was given by the trial judge to whether the opinions to be expressed by Ms Pineda could be given in the form of both a frequency of occurrence and an exclusion percentage. No separate consideration was given to the application of either s 135 or s 137 of the Evidence Act. And when Ms Pineda gave her evidence, she did so without further objection.
The appeal to this Court was argued on the footing that nothing turned on the way in which the arguments about admissibility were presented and resolved at trial. It is convenient to put aside those aspects of the matter and go at once to the evidence that the appellant submitted should not have been admitted. That is best done by setting out in full the answer which Ms Pineda gave to a question from the trial prosecutor: "Then having determined, as I understand it, that the profile found on the accused's saliva card and the profile found on the hair, occurs in one of the 4,839 people on the database, what did you then do?". Ms Pineda said:

It will be observed that the witness gave both a frequency ratio (one in 1,600) and an exclusion percentage (99.9 per cent) and that she explained how the exclusion percentage was calculated.
Shortly after Ms Pineda had given the evidence just described, the Court adjourned for the day. When she resumed giving her evidence on the following day of hearing, the trial prosecutor returned to the subject of a "95 per cent confidence interval". Ms Pineda explained that "to account for the size of the database we apply this confidence interval that tells us basically 95 per cent of the time you're going to see this profile not more often than one in 1,600 individuals". She continued: "[T]hat is the upper limit of that range. So that is the most conservative value that we can give you which gives the most benefit to the accused. It's the most frequently that we can expect to see this profile in the separate database." She concluded her answer by saying: "The 99.9 per cent figure is just the inverse of that. One in 1,600 is the frequency of occurrence - the expected frequency. The 99.9 per cent is the percentage of the [population] who could not have contributed to that sequence. So it's the same information, just looking at it in two ways."
Trial counsel for the appellant did not cross‑examine Ms Pineda about exclusion percentages. Trial counsel did, however, seek to give further content to the frequency ratio given by Ms Pineda by putting to Ms Pineda an example based on a group of 16,000 people attending a football match. Trial counsel put to Ms Pineda that "on one day, with 16,000 people in the football stadium, you might have 100 people with the same mitochondrial DNA as Mr Aytugrul", to which Ms Pineda replied, "And on other days you might have none." Asked: "So, is it an average?", Ms Pineda replied: "Yes".
The expert about DNA analysis called by the defence at trial (Dr John Buckleton, a scientist employed by the New Zealand Government) expressed the opinion that the DNA profile found in the hair taken from the deceased's thumbnail might be found in one in 1,000 people in the non‑Turkish population and between one in 50 and one in 100 or 200 people in the Turkish population. In the course of Dr Buckleton's evidence the trial judge referred Dr Buckleton to Ms Pineda's evidence that the frequency ratio she had given (one in 1,600) could be expressed as an exclusion percentage. As recorded in the transcript, there appears to have been some confusion about the number that Ms Pineda was said to have given as the exclusion percentage, reference being made to 99.5 per cent, 99.95 per cent and 99.99 per cent, whereas in her evidence Ms Pineda had rounded the exclusion percentage to one decimal place and stated it as 99.9 per cent. The trial judge put to Dr Buckleton that the difference between him and Ms Pineda was that "she's saying 99.95 and you're saying it should be more like 99.9, just on this mathematical exercise you're referring to". Dr Buckleton responded: "I consider the arguments regarding sampling and certainty to be marked with a lesser of the two evils. So in fact the difference, as you pointed out, is quite minimal." (emphasis added)
In his directions to the jury, the trial judge said:

In his dissenting reasons, McClellan CJ at CL treated the ground of appeal pleaded by the appellant (that a miscarriage of justice had occurred because of the prejudicial way in which DNA evidence was expressed to the jury) as raising a particular instance of a more general issue identified as the "intelligibility"[7] of DNA evidence or "juror comprehension of statistical evidence"[8]. McClellan CJ at CL made reference[9] to a number of published articles examining "the differing persuasive power of probabilistic formulations". Based on these writings, his Honour concluded[10] that "certain forms of expressing [DNA] statistics carry greater persuasive potential than others". It is neither necessary nor appropriate to consider whether what is said in those articles supports that conclusion, at least in a case where more than one form of expressing the statistics is adopted and the relationship between the expressions explained. In his Honour's opinion, the exclusion percentages given in evidence "all … invited a subconscious 'rounding up' to 100"[11]. Because of this "subliminal impact"[12], "[t]he exclusion percentage figures were too compelling"[13] which amounted to prejudice that was said[14] to substantially outweigh the probative value of the evidence. Reference was made to earlier decisions of the Court of Criminal Appeal (R v GK[15] and JCG[16]) where there had been consideration of whether use of percentage figures very close to 100 was likely to be prejudicial or misleading. McClellan CJ at CL would have allowed the appeal and ordered a new trial; his Honour would not have applied the proviso[17] because "the exclusion percentages had the potential to overwhelm the jury"[18].
Simpson J, with whose reasons Fullerton J agreed[19] in this respect, accepted[20] that some formulations of the conclusions to be drawn from DNA testing "are likely to have greater impact than others", in the sense that "some formulations have a greater educative force or persuasive appeal than others; or … are more colourful, or more easily comprehended, than others". But Simpson J further concluded[21]: "Provided that what is contained in the formulations is accurate, I see no reason to prefer one method of expression over another." On the contrary, Simpson J held[22] that it is "beneficial (provided that, in translating one formulation to another, accuracy is not sacrificed) for the conclusions drawn [from DNA testing] to be expressed in ways that can readily be comprehended by juries" and held[23] that there was no reason "why a jury ought not to be assisted by having the evidence couched in the language most likely to be meaningful to lay recipients". Simpson J saw nothing which suggested "that the [DNA] evidence before the jury, framed as it was, was unduly or unfairly prejudicial, or confusing or misleading such as to raise for consideration either s 135 or s 137"[24] and concluded that there was no "deficiency in the way in which the jury was directed in relation to the DNA evidence"[25]. Her Honour thus rejected[26] the ground of the appellant's appeal about presentation of DNA evidence.

No sufficient foundation was laid, at trial or on appeal (whether to the Court of Criminal Appeal or this Court) for the creation or application of a general rule of the kind described. It may readily be accepted that, as McClellan CJ at CL demonstrated[29], research has been undertaken into whether some "forms of expressing [DNA] statistics carry greater persuasive potential than others". It is evident that numerous articles have been published in well‑respected journals setting out the opinions of authors who have undertaken study of and experiments in relation to questions of this kind. But it is important to recognise that the relevant field of study is not the law but psychology. And it was not demonstrated (whether at trial, in the Court of Criminal Appeal or on appeal to this Court) that the methods used in the studies that have been made, or the results expressed in the articles to which reference was made, are methods or results that have attained such a degree of general acceptance by those skilled in the relevant disciplines as would permit a court to take judicial notice of some general proposition about human understanding or behaviour said to be revealed by the published literature.
Before a court could take judicial notice of such a general proposition, the provisions of s 144 of the Evidence Act[30] would have to be met. As the majority of this Court noted in Gattellaro v Westpac Banking Corporation[31], "[i]n New South Wales there would appear to be no room for the operation of the common law doctrine of judicial notice, strictly so called, since the enactment of the Evidence Act 1995 (NSW), s 144". In this case, knowledge of the proposition in question could not be said to be "not reasonably open to question" and "common knowledge" or "capable of verification by reference to a document the authority of which cannot reasonably be questioned". And whether, in accordance with s 144(4), a sufficient opportunity was given to the parties to make submissions and to refer to relevant information such as was necessary to ensure that neither party was unfairly prejudiced by the court acquiring or taking into account "knowledge" of this kind need not be decided.
No proof was attempted, whether at trial or on appeal, of the facts and opinions which were put forward (by reference to the published articles) as underpinning the adoption of some general rule that expressing the results of DNA analysis as an exclusion percentage will always (or usually) convey more to a hearer than the evidence allows regardless of what other evidence is given about frequency ratios or the derivation of exclusion percentages. Yet that was the basis on which it was asserted that a general rule should be established to the effect that evidence of exclusion percentages is always inadmissible. And absent the proof of such facts and opinions (with the provision of a sufficient opportunity for the opposite party to attempt to controvert, both by evidence and argument, the propositions being advanced) a court cannot adopt such a general rule based only on the court's own researches suggesting the existence of a body of skilled opinion that would support it.
The question that was presented for consideration in this matter must be identified with greater specificity than is permitted by general reference to how the human mind can or commonly will deal with statistical information. In this case, the question was whether Ms Pineda's evidence of an exclusion percentage accompanied by both reference to the relevant frequency ratio and an explanation of how the exclusion percentage was derived from the frequency ratio was evidence whose probative value was outweighed by the danger of unfair prejudice (s 137) or was evidence whose probative value was substantially outweighed by the danger that it might be unfairly prejudicial to the defendant or, perhaps, be misleading or confusing (s 135).
No reason is shown for answering either form of those more particular questions in favour of the appellant. The evidence given was clear. It was evidence adverse to the appellant but it was in no sense unfairly prejudicial, or misleading or confusing. The exclusion percentage given was high - 99.9 per cent - but relevant content was given to that figure by the frequency ratios that were stated in evidence. As the trial judge pointed out to the jury, the evidence that was given did not, and was not said to, establish that the mitochondrial DNA profile found in the hair definitely came from the appellant. There was no risk of rounding the figure of 99.9 per cent to the certainty of 100 per cent.
The appellant also placed emphasis on evidence of the frequency ratios for a different reason. The appellant submitted that, if evidence was given in the form of frequency ratios, the exclusion percentage was evidence that "could not add anything of substance to" the frequency ratio or "could not, in any significant way, rationally add anything to the jury's assessment of the probability of the appellant's guilt". That is, so the submission ran, the "incremental probative value" of the exclusion percentage was "minimal". It was said that the proper application of ss 135 and 137 "would require exclusion if there was any risk of the jury giving more weight to the [exclusion] percentage evidence than it deserved" (emphasis in original).
These submissions, too, should be rejected.
This aspect of the appellant's submissions proceeded from an understanding of the term "evidence" that sought to apply both s 137 and s 135 on the footing that "evidence" about frequency ratios would be different and distinct from "evidence" about exclusion percentages[32]. Given the mathematical equivalence of the two statements, there may be some doubt about the validity of approaching the application of the two sections on the basis that there were two distinct pieces of evidence in issue. There is no need, however, to resolve this question.
The appellant accepted that the evidence about exclusion percentages was relevant - that is, that it was evidence that could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue[33]. The appellant's submissions thus accepted that evidence expressed in the form of an exclusion percentage had, of itself, some probative value. And given that the exclusion percentage and the frequency ratio were no more than different ways of expressing the one statistical statement, the probative value of the exclusion percentage was necessarily the same as that of the frequency ratio.
The appellant's submission amounted in substance to an assertion that regard should be had to other evidence (the frequency ratio) in assessing the probative weight of the exclusion percentage but that regard could not be had to that other evidence when assessing the danger of unfair prejudice. There is no reason to approach the inquiry in this unbalanced way.
The unfair prejudice said to arise in this case was alleged to flow from the use of a percentage figure, which carried a "residual risk of unfairness deriving from the subliminal impact of the raw percentage figures"[34] by way of rounding up the percentage figure to 100. If the exclusion percentage were to be examined in isolation, the appellant's arguments appear to take on some force. But to carry out the relevant inquiry in that way would be erroneous. In this case, both the frequency ratio and the manner in which the exclusion percentage had been derived from the frequency ratio were to be explained in evidence to the jury. The risk of unfair prejudice - described by the appellant as the jury giving the exclusion percentage "more weight … than it deserved" - was all but eliminated by the explanation. It is not right, as the submissions of the appellant implicitly urged, and as appears to have been the approach taken in R v GK[35], to assess the danger of unfair prejudice by reference only to the exclusion percentage, ignoring all other evidence. In assessing the danger of unfair prejudice to a defendant, regard must be had to the whole of the evidence that is to be given, particularly by the witness to whose evidence objection is taken. When that is done in this case, recognising, in particular, the evidence that it was proposed to lead from the witness about the derivation of the exclusion percentage, there was no danger of unfair prejudice that required rejection of the exclusion percentage.
At one point in oral argument, counsel for the appellant did suggest that there was a danger that the evidence of the exclusion percentage might "be misleading or confusing"[36]. Given the context of evidence of the frequency ratio and how the exclusion percentage was calculated, there was no danger that the evidence of the exclusion percentage might be misleading or confusing. The appellant did not demonstrate that the proper exercise of the discretion given by s 135(b) required rejection of the evidence of exclusion percentage.
There may be cases where evidence given of exclusion percentages may warrant close consideration of the application of s 135 or s 137 (or, where applicable, equivalent common law doctrines or statutory provisions). These reasons are not to be read as suggesting to the contrary. Evidence given about the results of DNA analysis is evidence about comparisons between identified samples and one or more databases. The results of those comparisons can be expressed qualitatively or quantitatively. If expressed quantitatively there are assumptions and approximations made which often (perhaps always) require elucidation and explanation to make plain what are the limits to the opinion that is being expressed as a number or range of numbers. Just as evidence of an opinion given by an expert must, in order to satisfy the requirements of admissibility in s 79(1) of the Evidence Act, be "presented in a form which makes it possible to answer" the question posed by that provision[37], it will usually be important, even necessary, that the evidence provides the jury with so much of the expert's "specialised knowledge" as the jury requires properly to understand the opinion expressed - and what it can and cannot demonstrate - and that this specialised knowledge be related to the facts of the case[38].
It may very well be right to observe that a frequency ratio of one in 1,000 can, even may often, convey a different message to the hearer than does an exclusion percentage of 99.9 per cent, because the denominator of the frequency ratio directs the hearer's attention to the population that must be considered when seeking to apply the ratio. (Of course, a percentage, too, is a ratio but may direct less attention to the denominator.) Not only that, it is important to recognise that evidence of DNA analysis tendered by the prosecution is tendered in proof of a case that the accused is guilty of the offence charged. It is not usually tendered only to exclude the possibility that there may be others who committed the offence (unless the possible class of offenders is limited). It is usually tendered to show that there is at most a small pool of persons, including the accused, who could have left a trace at the scene of the crime. But demonstrating that there are many persons in Australia who did not commit the crime charged against the accused may be thought, if that information is considered in isolation, to tend to distract attention from whether the accused is the one out of the remaining number of possible perpetrators who did commit the crime.
In this case, where both the frequency ratio and the exclusion percentage were given, and the relationship of one to the other was explained, there was neither a wrong decision of any question of law nor on any other ground a miscarriage of justice.
The appeal to this Court should be dismissed.
HEYDON J. Gina Pineda gave evidence that the appellant had a particular DNA profile (a "mitochondrial haplotype"). She also gave evidence that the same mitochondrial haplotype was detected in a hair found under a nail of the deceased when she was discovered in her new apartment, which the appellant was said never to have visited. And she gave evidence that one in 1600 persons could be expected to have the same mitochondrial haplotype as was detected in that hair. The appellant called this a "random occurrence ratio" or a "frequency estimate". It expresses the frequency with which the profile can be expected to occur in the general population. The appellant did not deny, at least in the Court of Criminal Appeal and in this Court, that that evidence was admissible.
Gina Pineda also gave evidence of what the appellant called an "exclusion percentage". That percentage represents the proportion of the population who would not be expected to share the mitochondrial haplotype. The percentage she gave was 99.9%. As the appellant accepted, that is mathematically the same as the one in 1600 figure. It follows from the frequency estimate of one in 1600 people that 1599 of the 1600 people would not be expected to share the mitochondrial haplotype. That figure, expressed as a percentage, is approximately 99.9%. The appellant contends, however, that the trial judge failed in his duty to refuse to admit the evidence, since its probative value was outweighed by the danger of unfair prejudice to the appellant. For that submission, the appellant relied on s 137 of the Evidence Act 1995 (NSW) ("the Act")[39]. The appellant also contended that even if there were no unfair prejudice, the trial judge ought to have refused to admit the evidence since its probative value was substantially outweighed by the danger that the evidence might be misleading or confusing. For this alternative submission, the appellant relied on s 135(b) of the Act[40].

The appellant claimed support for the argument in Old Chief v United States[44]. In that case the accused was charged with illegal possession of firearms. The Supreme Court of the United States held, by majority, that evidence of a prior conviction for assault causing serious bodily injury should have been excluded. In the majority's view, the evidence fell within the terms of the Federal Rules of Evidence, r 403[45]. The majority said that its "probative value [was] substantially outweighed by the danger of unfair prejudice". At the trial the accused had indicated preparedness to concede that he had "been convicted of a crime punishable by imprisonment exceeding one (1) year"[46]. The opinion of the Court was delivered by Souter J, in which Stevens, Kennedy, Ginsburg and Breyer JJ joined. That majority held that the fact which the accused wished to concede was relevant because the accused was charged with contravening 18 USC s922(g)(1). That provision made it unlawful for anyone "who has been convicted in any court of … a crime punishable by imprisonment for a term exceeding one year" to "possess in or affecting commerce, any firearm". The majority also accepted that the name and nature of the accused's prior offences contained in the official record of his prior conviction were relevant. Those matters made it more probable that the accused's status was that described in s922(g)(1). But the majority considered it wrong to examine the probative value of the evidence tendered in isolation[47]. The evidence tendered - the official record of the conviction - added nothing to the evidentiary significance of the concession the accused was prepared to make[48]. The probative value of the evidence tendered had to be "discounted" for that reason[49]. Hence the danger of unfair prejudice in the evidence tendered substantially outweighed its "discounted" probative value.
Rule 403 corresponds substantially with s 135(a), not s 137. However, the appellant relied on Old Chief v United States as an authority casting light on what is meant by the expression "probative value", as it appears in both ss 135 and 137. The majority opinion in Old Chief v United States, in a passage which the appellant relied on, considered that there were two possible constructions of the provision. The first was as follows[50]:

The appellant also claimed support for his argument about the meaning of "probative value" in ss 135 and 137 from Driscoll v The Queen[66]. The appellant submitted that s 137 was based on what the Australian Law Reform Commission called a common law "discretion to exclude evidence adduced by the prosecution if it is more prejudicial than probative."[67] This "discretion" was discussed in Driscoll v The Queen. That case examined what was, at that time, a growing problem. The problem arose because there was no general practice by which interviews between police officers and suspected persons were mechanically recorded. A typical manifestation of the problem was as follows. Police officers would testify that the accused had made an oral confession; that a written record of the interview in which it was given had then been prepared; that the accused had acknowledged its correctness; but that the accused had then refused to sign it. The accused might then deny at the trial having made the oral confession or having acknowledged the correctness of the written record.
This posed difficulties for the just and reasonably expeditious conduct of trials. Those difficulties have been much reduced by two factors. One is the wider availability of equipment for making audiovisual and audio recordings of police interrogations. The other is legislation requiring the making of those recordings as a condition of admissibility[68]. However, the problem was regarded as very serious at the time Driscoll v The Queen was decided. It was believed that in some cases police officers were lying about whether the oral confession had been made. It was believed that in other cases accused persons were lying on that topic. The circumstances gave police officers a considerable amount of power. Some police officers were motivated by an excess of zeal. They desired to ensure the conviction of those whom they believed to be guilty, even though they lacked complete evidence of guilt. For their part, accused persons by the time of their trials had got into an uncomfortable position, giving them a strong motive to lie about what they might have said before their trials. It was difficult to judge where the truth lay.
At the time Driscoll v The Queen was decided, the orthodox position in relation to admissibility was as follows. The police officers could give evidence about their recollections of the oral confession. In giving that evidence, witnesses who prepared or supervised the preparation of a statement for the accused to sign, or who read it while the facts were fresh in their memories, could refresh their memories, before the trial or in court[69]. That would not make the statement itself admissible. Nor would giving a cross-examiner access to it for the purposes of inspection make it admissible[70]. It could only become admissible if the cross-examiner cross-examined on parts of the document not used to refresh memory. If the police officers were not able to testify that the accused had adopted the record of a confession, by signature or otherwise, that record was not admissible[71]. However, if the accused had adopted the record, by signature or by some other means to which the police officers testified, it was, strictly speaking, admissible[72].
In Driscoll v The Queen Gibbs J (Mason, Jacobs and Murphy JJ concurring) made a valuable statement about the law and the problem. It falls into three parts.
The first was[73]:

In the third part Gibbs J was pointing to two sources of unfairness or prejudice to the accused created by evidence about the accused's adoption of an unsigned record of interview. The evidence was inherently suspicious. If the police officers were correct in saying that the accused confessed, the fact that soon after the confession the accused declined to sign a record of the confession called for explanation.
There is only one aspect of Driscoll v The Queen which could be said to advance the appellant's argument that the reasoning in Old Chief v United States applies to ss 135 or 137, or applied in relation to the common law principles which preceded them. That is the italicised sentence quoted above in the second part of Gibbs J's statement. However, it does not in fact support the appellant's argument. Gibbs J's statement that an unsigned record of interview used to refresh memory will add nothing to the weight of the police officers' testimony about the confession is correct. A record of interview neither signed nor otherwise acknowledged by the accused to be correct was inadmissible. It contravened the rule against hearsay. At that time, in most Australian jurisdictions, there was no applicable exception to that rule, and in particular no exception for business records. Hence the only admissible evidence was the oral evidence of the confession. Where oral evidence had been given by a witness who had refreshed memory from a document, a change in the law to permit reception of the document into evidence would have added nothing to the weight of the testimony. The document was not independent of the witness. The testimony would very often have been wholly or partly a product of having read the document. The same considerations also explain Gibbs J's statement that a record of interview "will in itself be of little evidential value" where it has not been acknowledged by signature. That was equally true of records of interview not otherwise acknowledged.
In the second passage, Gibbs J was not propounding any general doctrine that the probative value of a particular piece of evidence depended on assessing its marginal significance when compared to the other evidence in the case. The conclusions in Old Chief v United States rest on a comparison between two admissible pieces of evidence. Gibbs J was not comparing two admissible items of evidence and deciding that in view of the existence of the first the probative value of the second was "discounted". Instead Gibbs J was comparing two pieces of evidence. One was admissible - the oral testimony. The other was inadmissible - the unsigned record of interview. Gibbs J made the comparison in order to reject the suggestion that a hearsay exception be created.
In contrast, in the third part of what he said, Gibbs J was comparing two pieces of evidence which were, strictly speaking, admissible. He was making the point that the unsigned record of interview which a police officer swore had been adopted by the accused might have little weight. But that was not because its probative value was to be "discounted" in view of the oral evidence. It was simply because the oral evidence about the accused making the confession and the oral evidence about the accused adopting the record of interview had the same source.
For these reasons Driscoll v The Queen does not support the appellant's submission that s 137 should be given a construction similar to that which the majority in Old Chief v United States gave to r 403 of the Federal Rules of Evidence.

The appellant submitted that the evidence that 99.9% of the population could not be the offender created prejudice of the following kinds. It encouraged mathematical rather than deductive reasoning. It carried a risk of fallacious reasoning, including encouraging the jury to give undue attention to the seeming precision of figures. And it distracted attention from what should have been the central focus - the possibility that the hair found on the deceased was not the appellant's but someone else's. The appellant relied on R v GK[79], which held that DNA evidence giving a relative chance of paternity of 99.9995% and 99.9993% was rightly excluded under s 137. The basis for exclusion was "the residual risk of unfairness deriving from the subliminal impact of the raw percentage figures"[80]. The appellant also relied on R v JCG[81], which followed R v GK. The appellant submitted that since those decisions it had become common practice in Australian courts for evidence of the statistical probability of a DNA match to be expressed as a "random occurrence ratio" or a "frequency estimate", rather than as an "exclusion percentage". The appellant relied on R v Doheny[82], in which the latter practice was disfavoured. The appellant relied on writings by experts, including analysis of experimental research, on juror comprehension, or incomprehension, of DNA evidence. This Court was taken to some of these writings. McClellan CJ at CL relied on writings of that kind in his dissenting judgment[83]. Two problems arise. The first is that according to the appellant in this Court, that material was not relied on by either party in the Court of Criminal Appeal and was not raised in argument for their consideration. The second problem is that no evidence supporting the reasoning in the expert writings had been tendered to the trial judge or to the Court of Criminal Appeal.
So far as the first problem is concerned, in view of the fact that the learned Chief Judge was in dissent, it cannot be said that the party against whom he found, the prosecution, was not given an opportunity to deal with a point on which that party lost, for it did not lose: the majority accepted its submissions[84]. The appellant did accept that it was desirable that material of that kind be ventilated with the parties so that the party against whose interests the material operates can seek to deal with it. That is certainly so if that party loses on the point. It may be that dissenting judges have greater latitude than majority judges in this respect: their views are adverse to the winning party, but can do that party no harm.
The second problem is that the court is unaided by contributions from the parties in relation to understanding the material and in relation to the possibility that other experts disagree with or wish to qualify its teachings. The problem is alleviated when the material is received through expert witnesses.
The teachings of the expert material could have been employed in two ways. They could have been employed before the jury as a warning against the dangers of uncritically accepting the statistical evidence. So used, the material would have been similar to evidence admitted in the United States about the fallibility of eyewitness identification[85], the low rate of recidivism among those convicted of murder on a hearing to determine sentence[86], the relevance of "battered woman syndrome" to self-defence[87] and the characteristics of abused children[88]. And, so used, it would have been similar to evidence admitted in Australia about "infantile amnesia"[89], the effect of mental impairment on a witness's powers of observation, recollection or expression[90], the language or communications difficulties bearing on the ability of Aboriginal witnesses to give reliable or complete evidence[91], the relevance of "battered woman syndrome" to duress[92], the incidence of recovered memory syndrome[93] and the effects on children of separation from their parents[94].
Material of this kind does not establish "adjudicative facts". Adjudicative facts are those facts which are in issue or are relevant to a fact in issue and are determined by the jury, or, in non-jury trials, by the trial judge. Dixon CJ described them as "ordinary questions of fact which arise between the parties because one asserts and the other denies that events have occurred bringing one of them within some criterion of liability or excuse set up by the law".[95] But the material just referred to establishes general principles against which the court can assess particular evidence, or the conduct of a party or witness. That is, it helps the court to assess adjudicative facts. When material of this kind is so used, it must be established by evidence. The appellant's reliance on the material was rather directed to establishing that "exclusion percentage" evidence was always or almost always so prejudicial, and so little lacking in probative value once "frequency estimate" evidence had been admitted, that s 137 should invariably be employed to exclude it. Section 137 is not expressed in the language of discretion, but it does depend on a weighing process. The inquiry is whether the probative value of a specific piece of evidence is "outweighed" by the danger of unfair prejudice flowing from that specific piece of evidence. An inquiry of that kind is not lightly to be trammelled by universal or general rules.
Putting that problem aside, the appellant appeared to be urging the creation of a legal rule, in the sense of a hitherto unsuspected construction of s 137. He did so by recourse to the "legislative facts" to be found in the expert material. Legislative facts are to be distinguished from "adjudicative facts". Legislative facts are those which help the court to determine what a common law rule should be or how a statute should be construed[96]. They reveal how existing rules work and how rules which do not exist might work if they were adopted. Sometimes legislative facts can legitimately be derived by analysing factual material not tendered in evidence either at trial or on appeal. That analysis can operate in many fields, but some of them are fields dependent on expert learning. Thus sometimes general references are made by courts to the causes of psychiatric injury[97] and the diagnosis of psychiatric illness[98]. Sometimes more specific reasoning is propounded after the court has had recourse to expert literature. Medical works have been taken into account in assessing the causation and foreseeability of psychiatric injury[99]. Works on psychology have been considered in formulating rules about identification evidence[100], both directly[101] and indirectly[102]. This is not surprising, since the court's recognition of the "inherent frailties of identification evidence" has been said to arise "from the psychological fact of the unreliability of human observation and recollection."[103] If frailty rests on a psychological fact, and on psychological research[104], expert material bearing on the psychological fact must have potential significance. Works on psychiatry have also been considered in explaining why children delay in complaining of sexual assault in relation to the unsafe and unsatisfactory ground of criminal appeal[105]. Expert studies on prison informants have been relied on to justify the proposition that evidence from that source may be tainted, and hence to justify the giving of warnings about it[106]. Psychiatric studies on the harm suffered by child victims of sexual offences have been taken into account in developing sentencing principles[107]. Accounting textbooks have been referred to in order to explain the differences between two methods of accounting. The goal was to determine which method reflected the legal test for accounting for general overheads in relation to an account of profits as a result of patent infringement[108]. Considerable reliance has been placed on environmental health studies in concluding that landlords had a duty of care to the son of tenants[109].
The appellant did not make clear how this Court could take the expert material into account.
One possibility was by way of judicial notice. Assuming that s 144 of the Act[110] impliedly abolishes the corresponding common law doctrine of judicial notice[111], a question arises. Does s 144 apply to the reception of legislative facts? If it does, there is a difficulty: it was not established that the material was "not reasonably open to question". However, s 144 may not apply to the reception of legislative facts: the Australian Law Reform Commission itself was in some doubt about its application to a particular type of legislative fact called "constitutional facts"[112]. If it does not, and if the common law position continues, it is unlikely that the material was sufficiently uncontroversial for judicial notice to be taken of it.
Another possibility is to treat the expert material as a matter of "common knowledge". The courts have relied on legislative facts as being within matters of "common knowledge" in a sense much wider than that used in s 144. That is, they have resorted to legislative facts even though they could not be said to be "not reasonably open to question" because minds differ about them. However, the level of technical sophistication involved in the material on which the appellant relied is so great that it would not be satisfactory for this Court to take it into account without the assistance of expert witnesses who had been cross-examined. It would be very difficult for this Court, without that aid, to resolve any controversies which may arise. To borrow the words of Judge Frank speaking about psychiatry, it would be dangerous for the Court "to embark - without a pilot, rudder, compass or radar - on an amateur's voyage on [this] fog‑enshrouded sea."[113] The appellant submitted that the respondent had not made "any significant challenge to the research" relied on. Even if this is so - and the respondent disagreed - if the expert material were to be taken into account, it was highly preferable that it be presented through expert witnesses, preferably during a pre-trial hearing to determine admissibility. The admissibility and weight of the expert material could then be considered publicly and critically.

There was no unfair prejudice for the following reasons. No doubt both the "frequency estimate" and the "exclusion percentage" evidence, like many other aspects of the expert evidence, were difficult for the jury to deal with. The field is arcane. But any criminal jury of 12 is likely to contain at least one juror capable of realising, and demonstrating to the other jurors, that the frequency estimate was the same as the exclusion percentage. Further, detailed evidence was given about how the "exclusion percentage" evidence was derived from the concededly admissible "frequency estimate" evidence, and how their significance was identical. The case is entirely distinguishable from cases like R v GK, where a higher exclusion percentage was used in a quite different fashion. Those cases are authorities for what they decide. They do not establish absolute rules[114]. The trial judge made it plain while argument was proceeding about the reception of the "exclusion percentage" that no-one participating in the trial would express that percentage as being "somewhat like the 'prosecutor's fallacy', that is it's 99 percent sure that it is the accused". No-one did. In addition the reception of evidence which might sometimes create unfair prejudice can be lawful if the conduct of the trial, including the possibility of a curative influence from other evidence, from counsel's handling of the impugned evidence and from the trial judge's directions, is likely to nullify or water down the prejudice. Whether this was foreseeable or not at the time of tender, counsel here treated the exclusion percentage as a minor aspect of the case. It was mentioned only rarely. After its initial reception, it was mentioned once by Gina Pineda, once by a defence witness and not at all by counsel in address. The trial judge's summing up pointed out that the exclusion percentage was "another way" or "the reverse way" of putting the frequency estimate. The trial judge warned against treating the mitochondrial haplotype evidence as "definitely" or "necessarily" establishing that the hair came from the appellant. There was no request from the appellant for the trial judge to withdraw any part of his summing up, or to give a curative direction or warning. There is no ground of appeal in this Court that the summing up was wrong. Even if not all these post-tender events were foreseeable, they amounted, as Wigmore might have said, to a restrospectant demonstration that there was no unfairness.
Once it was accepted that the "frequency estimate" evidence was admissible, the reception of the "exclusion percentage" evidence did not create a danger of unfair prejudice within the meaning of s 137.

Aytugrul v The Queen

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Judgment (117 paragraphs)

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Legislation Cited (14)

Cases Cited (58)

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