Tag: HCA

When will an expert’s opinion be shown to be based on their specialised knowledge?: Lang v The Queen [2023] HCA 29

In Lang v The Queen, the High Court considered whether a forensic pathologist’s opinion – that the deceased’s wounds were more likely inflicted by another person than self-inflicted – was founded on their expert knowledge within the field of forensic pathology (and thus, whether the opinion was admissible as expert opinion evidence).

Lang was heard on appeal from the Court of Appeal of Queensland. There were two grounds of appeal in both the Court of Appeal and the High Court, though this post is concerned only with the second ground, which was that a miscarriage of justice was caused by the wrongful admission of the forensic pathologist’s evidence at trial.

The appellant argued that the opinion evidence from Dr Ong (the forensic pathologist) was inadmissible because it was not demonstrated to be based on his expert knowledge in forensic pathology.

Ultimately, a majority of the High Court (Kiefel CJ, Gageler and Jagot JJ, Gordon and Edelman JJ in dissent) dismissed the appeal, noting as to the second ground that:

‘… we cannot conclude that, in engaging in the process of reasoning which led to the formation of the opinion, Dr Ong did other than draw substantially on his specialised knowledge.’ (Kiefel CJ and Gageler J at [26])

and

‘It is clear from a fair reading of the transcript of Dr Ong’s evidence that the impugned evidence was based on his specialist knowledge and reflected the combined effect of that knowledge brought to bear on multiple facts that he could ascertain only by reason of his specialist expertise…’ (Jagot J at [469])

As an appeal from Queensland, this case concerns the common law of evidence. However, as stated by Kiefel CJ and Gageler J in their joint judgment (at [11]), the relevant requirement (for the expert’s opinion to be shown to be based, at least substantially, on their specialised/expert knowledge) applies equally under the Uniform Evidence Law.

BACKGROUND

The deceased died from blood loss secondary to a stab wound to her abdomen. The only two people in the deceased’s apartment at the time of her death were the deceased and the appellant. It was accepted at trial that there were only two possible explanations for her death: either the deceased was killed by the appellant, or the deceased died by suicide. The prosecution case at trial was the former explanation.

In support of their case, the prosecution adduced evidence from a forensic pathologist, Dr Ong (who had performed an autopsy of the deceased and produced a postmortem report based on that autopsy), that the deceased’s wounds were more likely to have been inflicted by another person than self-inflicted. Dr Ong’s evidence was adduced over objection made by the appellant and ultimately found to be admissible by the trial judge in a pre-trial hearing.

The appellant accepted that forensic pathology was a field of expertise, that Dr Ong was an expert in forensic pathology, and that the question of whether wounds may have been self-inflicted or inflicted by another was capable of being the subject of expert evidence if ‘a suitable foundation as to the [witness’s] training, study or experience has been laid’. Therefore, the crux of the issue was whether or not the opinion was shown to be based on Dr Ong’s expert knowledge.

Dr Ong said he took a number of factors into account in reaching the opinion that the wound was more likely to have been inflicted by another person than self-inflicted, such as the absence of evidence of self-harm (for example, incisions to the wrist). Dr Ong said that the factor he took most into account in forming his opinion was ‘the multiplicity of the stab wounds’ and the ‘rotation of the blade’.  Dr Ong gave evidence that there was a single penetrating stab wound, comprised of two internal thrusts of the knife in one direction, a partial retraction and rotation of the knife while it was mostly withdrawn from the deceased’s body, followed by a further two or three thrusts, with the knife rotated in a different direction to that of the first two thrusts. There was a single point of entry.

Critically, Dr Ong said in his evidence-in-chief in the pre-trial hearing that his opinion was based on his ‘logical sense of what happened’. In cross-examination at trial, Dr Ong said he had found no literature on a wound bearing the same features as the deceased’s (featuring as it did a single entry external wound, a couple of internal stabs, rotation, and then a couple of more internal stabs). He said had also not dealt with a case like this in his career.

The appellant submitted that Dr Ong’s opinion was, therefore, substantially based on his subjective view as to how a person may or may not act when attempting to die by suicide, rather than being properly based on his special expertise in forensic pathology.

JUSTICE JAGOT’S JUDGMENT

The leading judgment was written by Jagot J, with which Kiefel CJ and Gageler J agreed. Justice Jagot found that Dr Ong’s opinion was not based on his subjective view of human behaviour (a matter beyond his expertise) – rather, the conclusion that the wounds were more likely to be self-inflicted was based on the wounds themselves and his experience as a forensic pathologist. Justice Jagot relevantly said:

‘It is apparent that Dr Ong was not purporting to give evidence as to the deceased’s psychological state or, indeed, the psychological state of any person who ends their own life. He was explaining that the evidence of the wounds themselves…, based on his expertise and experience over 25 years, led him to the conclusion that the wounds were more likely to be inflicted by another person than to be self inflicted. It is because drawing conclusions from wound patterns involves a process of deductive reasoning based on expertise as a forensic pathologist, and because he had no expertise to opine as to the particular psychology of the deceased at the time of the infliction of the wounds (and did not so opine), that he could not rule out the possibility that the wounds were self inflicted.’ (at [468])

As to whether Dr Ong could form such a conclusion without having encountered an identical case in his experience or in the literature, Jagot J said that ‘the essence of expertise is the capacity to reason from facts based on specialist training, study, or experience’ (at [469]):

‘… The fact that Dr Ong had not identified such a sequence of events in either a suicide or a homicide caused by stabbing does not mean that his evidence was not based on his expertise and does not mean his evidence lacked a rational foundation… it is highly unlikely that any case of suicide or homicide reported in the literature will be identical to an actual case which confronts a forensic pathologist… He is entitled to bring to bear all his specialist training, study, or experience to form an opinion without being able to point to an identical or even similar case. It is clear… that the impugned evidence was based on his specialist knowledge and reflected the combined effect of that knowledge brought to bear on multiple facts that he could ascertain only by reason of his specialist expertise…’ (at [469], emphasis added)

Justice Jagot thus dismissed the ground of appeal.

CHIEF JUSTICE KIEFEL AND GAGELER J’S JUDGMENT

Chief Justice Kiefel and Gageler J agreed with Jagot J, but wrote separately from the lead judgment to elaborate on the common law principles which bore on the admissibility of Dr Ong’s opinion.

In particular, their Honours discussed the requirement for an expert witness to reveal to the court their process of reasoning, so as to demonstrate that their opinion is based on application of their specialised knowledge to the relevant facts. Drawing on Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305, as applied in Dasreef Pty Ltd v Hawchar [2011] HCA 21, Kiefel CJ and Gageler J noted that:

‘…in order to satisfy the condition of admissibility that the opinion of an expert be demonstrated to be based on specialised knowledge or experience, the inference drawn by the expert which constitutes the opinion [must] be supported by reasoning on the part of the expert sufficient to demonstrate that the opinion is the product of the application of the specialised knowledge of the expert to facts which the expert has observed or assumed.’ (at [11])

Their Honours noted that this requirement exists both at common law and under the Uniform Evidence Law (at [11]). They also noted that the standard set explicitly by the Uniform Evidence Law – that an expert’s opinion need only be ‘substantially based on’ their specialised knowledge – applies equally at common law (at [12]).

Their Honours also noted that for the purposes of admissibility, the relevant question is simply whether the process of reasoning is sufficient to demonstrate that their opinion is the product of the application of their expert knowledge to the facts. Whether or not the reasoning is clear and convincing does not go to admissibility, but is relevant to how much weight the fact-finder might afford to the opinion:

‘Here, it is important to highlight a distinction touched on but not elaborated upon in Makita. The distinction is between the present question as to whether a process of reasoning engaged in by an expert is sufficient to demonstrate that his or her opinion is the product of the application of specialised knowledge and the question of the extent to which a process of reasoning engaged in by an expert through the application of specialised knowledge is clear and convincing. Both questions can be described as going to the utility or value of the opinion. However, it is the present question alone that goes inexorably to the “admissibility” of the opinion as distinct from its “weight”. In addressing the present question of whether the opinion satisfies the condition of admissibility that the opinion be demonstrated to be based on specialised knowledge or experience of the expert, lack of cogency in so much of the reasoning as is found to involve application of specialised knowledge is not to the point: “the giving of correct expert evidence cannot be treated as a qualification necessary for giving expert evidence”.’ (at [15]–[16])

Chief Justice Kiefel and Gageler J went on to note that the cogency of an expert witness’ reasoning could affect the admissibility only if and when a court is called upon to decide whether its probative value is outweighed by its prejudicial effect (ie, when applying the Christie discretion at common law, or ss 135/137 of the Uniform Evidence Law).

It is of particular interest that their Honours said ‘assessing the probative value of the opinion [by] having regard to the cogency of the reasoning proffered in evidence in support of it involves no departure from the now settled principle that the assessment of the probative value of evidence requires that evidence to be “taken at its highest”: taking evidence at its highest involves making no assumption that the evidence in question is convincing’ (at [17]). Though these principles have been stated and settled previously, it is worth noting the inherent difficulty – at least in some cases – involved in teasing apart notions of credibility and general reliability (which are not to be considered when determining probative value) from the cogency of the reasoning (which can be considered as going to probative value).      

Turning to consider the case at hand, their Honours said ‘The overwhelming impression which emerges from reading the transcript is that of a professional and dispassionate forensic pathologist seeking to make sense of observed phenomena in respect of which neither his long experience nor his wide reading furnished an exact precedent.’ (at [20])

As to Dr Ong’s statement that he formed his opinion based on his ‘logical sense of what happened’, their Honours noted that ‘This expression was unfortunate in that it could be interpreted as Dr Ong saying that, in forming his opinion, he had drawn on some third source of background knowledge additional to his professional experience and the scientific literature. However, it is clear enough… that what he was saying was that he had engaged in a process of inductive reasoning which involved applying his knowledge of the interpretation of stab wounds to observed features of [the deceased’s] wound to form a conclusion about which of the two scenarios was more likely.’ (at [21])

Chief Justice Kiefel and Gageler J acknowledged that at trial, Dr Ong perhaps did not do a particularly good job of explaining why the wounds were more consistent with stabbing by another than they were with stabbing oneself. Their Honours said that ‘Absent a clearer explanation of Dr Ong’s process of reasoning, his opinion about whether the features of the wound which he identified were more consistent with stabbing by someone else might legitimately have been thought to have carried [little weight]… That weakness might well have been thought to have gone to the admissibility of Dr Ong’s opinion had the argument been advanced that its probative value was outweighed by its prejudicial effect.’ (at [25])

However, the argument put by the appellant was instead that the reasoning was not sufficient to demonstrate that the opinion was based on Dr Ong’s expert knowledge, and on that point Kiefel CJ and Gageler J agreed with Jagot J that the ground of appeal should be dismissed.    

CONCLUDING COMMENT

This case is interesting and helpful for a number of reasons. It provides a solid illustration of an opinion which is demonstrated to be based on expert knowledge even though the process of reasoning was not particularly clearly expressed. To that extent, it also demonstrates the distinction between ‘sufficient reasoning’ to demonstrate that the opinion is substantially based on expert knowledge, as compared to ‘cogent or convincing reasoning’ which chiefly goes to weight but can also affect probative value.

The case is also interesting because it speaks to and demonstrates a number of commonalities between the common law and Uniform Evidence Law tests for admissibility of expert opinion. A consequence of this is also that it is relevant to those practicing in all Australian jurisdictions – ie, it is presently relevant in Western Australia, and will continue to be relevant if/when the Uniform Evidence Law is adopted here.

This post is jointly authored by Julia Symons and Aidan Ricciardo

GBF v The Queen [2020] HCA 40

Background:
Though this High Court decision concerns an appeal from Queensland, it is relevant to the law in all Australian jurisdictions. The relevant background to this case is summarised in the first two paragraphs of the unanimous judgment by Kiefel CJ, Bell, Keane, Gordon and Edelman JJ:

‘The appellant appeals by grant of special leave from the orders of the Court of Appeal of the Supreme Court of Queensland (Morrison and Philippides JJA and Boddice J) dismissing an appeal against his convictions for six sexual offences. All the offences were alleged to have been committed against the appellant’s half-sister. The prosecution case was wholly dependent upon acceptance of her evidence. The appellant did not give or call evidence. In the course of his charge, Judge Wall QC instructed the jury to:

“bear in mind that [the complainant] gave evidence and there is no evidence, no sworn evidence, by the defendant to the contrary of her account. That may make it easier” …

The appellant challenged his convictions in the Court of Appeal contending that, in effect, the impugned statement was a direction that the absence of evidence from him might make it easier to return verdicts of guilty. The Court of Appeal acknowledged that the impugned statement should not have been made. Nonetheless, the Court of Appeal found there was no real possibility that the jury may have misunderstood earlier, correct directions of law that had been given, and no real possibility that the appellant had been deprived of a real chance of acquittal. Their Honours held that the impugned statement had not occasioned a miscarriage of justice. This holding took into account the fact that neither the prosecutor nor defence counsel had applied for any redirection arising from the making of the impugned statement.‘

In the High Court, the appellant challenged the Court of Appeal’s decision that the impugned statement did not occasion a miscarriage of justice. The appellant argued that it ‘invited the jury to reason to his guilt from his exercise of the right to silence’ and that the Court of Appeal was ‘bound to allow the appeal unless the prosecution established that no substantial miscarriage of justice had actually occurred’ ([3]).

Ultimately the High Court accepted the appellant’s submissions, allowed the appeal, and ordered a retrial.

Reasons:
The High Court found that the present case could not be distinguished from Azzopardi, in which it was stated:

‘It is to be emphasised that cases in which a judge may comment on the failure of an accused to offer an explanation will be both rare and exceptional … A comment will never be warranted merely because the accused has failed to contradict some aspect of the prosecution case.‘ ([68] of Azzopardi, reproduced at [21] of GBF)

In GBF there was no hint of any ‘additional facts which, if they existed, must be peculiarly within the mind of the Accused’ – therefore, there was no justification for any Weissensteiner-type of comment. Accordingly, the trial judge’s suggestion that the Accused’s silence might ‘make it easier’ for the jury invited them to engage in a false process of reasoning .

As put by the High Court, the comment’s ‘effect was to invite the jury to engage in the same false process of reasoning as the impugned passage did in Azzopardi. The Court of Appeal was wrong to hold that this was not an irregularity amounting to a miscarriage of justice’ ([26]).

Comment:
This decision adds to the significant body of case law which confirms that Weissensteiner-type comments are appropriate only in rare and exceptional circumstances. In light of GBF, it is likely that trial judges will be even more reluctant to make any mention of the accused’s silence, except for when giving the standard form of the Azzopardi direction. GBF also reinforces protection of an accused person’s right to silence, indicating that any mischaracterisation of that right at trial is likely to be regarded as a miscarriage of justice.

The judgment and further discussion:
The judgment was delivered on 4 November 2020 and can be accessed here.

For further discussion of this case, listen to ABC’s Law Report podcast from 24 November 2020 from 13 minutes and 10 seconds onwards (accessible here).

Nguyen v The Queen [2020] HCA 23; (2020) 94 ALJR 686

In brief:
Although an appeal from the Northern Territory, the High Court’s decision in Nguyen v The Queen impacts evidence law in all Australian jurisdictions.

Sometimes, in a criminal trial, the prosecution will bear a duty to adduce material evidence, regardless of whether it favours the prosecution case or not. This is to be distinguished from the prosecutorial obligation of disclosure. Disclosure is where the prosecution provides all relevant material to the defence, which may or may not be tendered into evidence during the trial. But, in some circumstances, the prosecution might also be obliged to adduce the evidence at trial, such as by calling witnesses relevant to the charge. This can be advantageous to the defence.1 The circumstances under which the prosecution is obliged to adduce evidence in a criminal trial was considered by the High Court in Nguyen v The Queen.

In this appeal the High Court unanimously affirmed the fundamental prosecutorial duty. All of the Justices held that, in the circumstances of the case, the prosecution was obliged to tender an electronic record of interview (EROI) of the police with the appellant at his trial. The Justices reasoned differently as to the circumstances in which the prosecution would be bound to adduce evidence.

Further background:
The appellant was charged on indictment of one count of unlawfully causing serious harm to another and one count of assault aggravated by the use of an offensive weapon.

The procedural history is notable in two respects. First, it commenced as a referral on a question of law. In many jurisdictions, a trial judge has the power to refer a question of law to an appeal court.2 In Western Australia, the procedure is available, but sparingly exercised.

Secondly, this was the appellant’s second trial. The first trial resulted in a hung jury (a type of mistrial where the jury is unable to reach agreement as to whether the accused is guilty or not guilty).

During the appellant’s first trial, the prosecutor played a video record of a ‘mixed interview’ to the jury. The appellant made mixed statements: comprising inculpatory statements (which tended to incriminate him) and exculpatory statements (which tended to introduce doubt as to his guilt). Although hearsay,3 the inculpatory statements were admissible as admissions against interest, and the exculpatory statements were admissible under the ‘mixed statement’ exception to the hearsay rule.

The contest arose as a result of the prosecutor’s decision, during the second trial, not to play the accused’s EROI to the jury. The prosecutor admitted this was a ‘tactical decision’.4 The Full Court of the Supreme Court of the Northern Territory (Kelly, Blokland and Barr JJ) held that the prosecutor was under no duty to tender the EROI.5

Decision of the High Court:
The majority of the High Court (Kiefel CJ, Bell, Gageler, Keane and Gordon JJ) affirmed the prosecutorial obligation in terms of adducing all ‘available, cogent and admissible evidence’:

What was said in [R v Soma] should be understood not just as a caution to prosecutors about being selective but rather as a reminder about the prosecutorial obligation to present all available, cogent and admissible evidence. Cases involving the omission of a vital witness may provide somewhat more stark examples of a failure properly to exercise that discretion than a mixed statement given by an accused in a police interview, but the latter may have just as important an impact on the outcome of the trial and the need for a new one.

at [39]

Their Honours noted that there may be cases where it was justified for the prosecution to not adduce evidence.

There may be circumstances where it would be unfair to an accused to tender a record of interview, for example where the accused has refused to comment. In such a circumstance the omission of that evidence is justified. But where an accused provides both inculpatory and exculpatory statements to investigating police officers, it is to be expected that the prosecutor will tender that evidence in the Crown case, unless there is good reason not to do so, if the prosecutorial duty is to be met.

at [41]

Their Honours accordingly held that the prosecutorial duty required the prosecution to adduce the EROI.

While agreeing with the outcome, Nettle and Edelman JJ both wrote individual concurring judgments, differing as to their reasoning. Justice Nettle expressed concern at the development of a general principle given that the decision to adduce evidence is a highly fact-sensitive and context-driven exercise. His Honour said:

… I am not persuaded, that the Crown’s obligation of fairness ordinarily extends to the presentation to the jury of “all available, cogent and admissible evidence” … [T]here may well be unexceptional cases in which a prosecutor would be perfectly entitled to choose not to tender available, cogent and admissible evidence without risk of unfairness to the accused.

…

Of course, each case depends on its own facts and circumstances, and, in the end, the question of whether a prosecutor’s decision not to tender some piece of evidence is productive of a substantial miscarriage of justice can only be judged in hindsight on appeal against conviction. But, if for no other reason than that, I am not willing to predicate as a proposition of apparently general application that the Crown’s obligation to put its case fully and fairly includes a prima facie duty to adduce all “cogent” and admissible evidence available to the Crown.

at [49]–[50] (citations omitted)

Justice Edelman demonstrated apparent concern over Nguyen‘s procedural path to the High Court, being an appeal from a referral of a question of law. His Honour considered it was difficult to discern, in advance, whether the failure to adduce the evidence would give rise to a miscarriage of justice.

A so-called “obligation” to tender a video record of interview, like a so-called “obligation” to call a witness, is not a free-standing obligation at all. It is an aspect of the prosecutor’s duty of fairness. The content of the prosecutor’s duty of fairness depends upon all the circumstances at trial. It can never be said with certainty prior to the conclusion of the prosecution case that a prosecutor’s duty of fairness would necessarily require a witness to be called or a video record of interview to be tendered. An initial impression that fairness would require a witness to be called or a video record of interview to be tendered might be affected by later circumstances, perhaps wholly unexpected, which might even make the tender of a video record of interview or calling of a witness unfair. If the second question referred to the Full Court were understood literally as asking, at a point prior to trial, whether there will be a legal obligation for the prosecution to tender the video record of interview during the prosecution case at trial then the answer would be “Impossible to answer”.

at [54]

However, his Honour was able to resolve the question by having regard to the manner in which the case was argued:

if the prosecutor were to maintain his stance throughout the Crown case of refusing to tender the video record of interview then it is likely that his conduct would be a breach of his duty of fairness and would lead to an unfair trial and a miscarriage of justice.

at [55]

Justices Nettle and Edelman agreed with the orders proposed by the majority, and the appeal was unanimously allowed.

The judgment was delivered on 30 June 2020. You can access it here (a summary is also available).

Endnotes:

1. This is because if the evidence is adduced by the prosecution, the defence is then able to advance their case in a way which might not be possible if the defence was required to adduce it during examination-in-chief. For example, if, during the State case, the prosecution calls a witness, the defence is able to cross-examine that witness. This means the defence can ask the witness leading questions, and can challenge the witness’ credit by contradicting them.

2. To give an example, the judge might be unsure as to whether certain evidence is admissible. Generally trial judges are more likely to make their own evidentiary rulings, leaving an appeal against conviction as the only avenue for the correction of error.

3. Hearsay is a statement made outside court which is adduced in a trial in order to prove the truth of its contents. Hearsay is generally not admissible because it is not reliable: the statement having not been made on oath or affirmation, and its maker having not been subjected to cross-examination. There is a fear that hearsay statements may have been concocted, ‘made up’, or embellished. Admissions against interest are an exception to the rule because the law considers that they are unlikely to have been made up (that is, people tend not to make statements against their interest unless the statements are true).

4. These two words might send chills down the spines of experienced prosecutors. It is worth bearing in mind that the High Court has warned that the prosecution’s role is not one of securing convictions at all costs, but of ensuring a fair trial of the accused. Accordingly, the failure of the State to call a witness may, depending on the circumstances, give rise to a miscarriage of justice. A selection of cases discussing this important proposition are: R v Apostilides (1984) 154 CLR 563; Whitehorn v The Queen (1983) 152 CLR 657, 663-4 (Deane J), 674 (Dawson J); Ritchie v Western Australia [2016] WASCA 134; (2016) 260 A Crim R 367, 375 [40], [42] (McLure P); R v Livermore (2006) 67 NSWLR 659; Bugeja & Johnson v R (2010) 30 VR 493. For a very rare example of a case where a witness was called by the trial judge in order to ensure a fair trial, when the prosecution refused to call the witness, see R v Peros [2018] 1 Qd R 1.

5. See R v Nguyen [2019] NTSC 37; (2019) 345 FLR 40.

This post is authored by Matthew Thompson and edited by Aidan Ricciardo.