1 I invite Osborn JA to deliver the first judgment.

2 On 30 August 2011, the appellant was convicted of seven charges arising out of sexual abuse of his daughter. In the course of his trial, a psychiatrist, Dr Daniel Sullivan, gave expert evidence on behalf of the Crown with respect to the behavioural framework within which the evidence of the complainant's reactions to the alleged abuse should be assessed and understood.

3 More particularly, Dr Sullivan gave evidence that:

(a) the failure of the complainant to cry out during the sexual assaults when other members of the family were in the vicinity was not an unusual behavioural reaction;

(b) the failure of the complainant's mother to accept the truth of a complaint made to her by her teenage daughter concerning sexual abuse by her father was not an unusual behavioural reaction and could be regarded as relevant to the complainant's behaviour thereafter; and

(c) the fact that the complainant maintained an ongoing relationship with her father for many years after the alleged abuse, despite both its occurrence and the failure of her mother to accept her complaint, was not demonstrative of an unusual behavioural reaction.

4 On 8 March 2012, Harper JA gave leave to appeal on the ground that it was reasonably arguable that Dr Sullivan did not possess the relevant expertise to give the evidence complained of.

5 On the hearing of the appeal, leave was granted to the appellant to further challenge the admissibility of Dr Sullivan's evidence on the grounds that it was:

(a) irrelevant in that it was incapable of rationally affecting any matter in issue in the trial (in accordance with s 55 of the Evidence Act 2008 ('the Evidence Act'));

(b) so unfairly prejudicial as to require exclusion pursuant to s 135 or 137 of the Evidence Act; and

(c) likely to have unfairly prejudiced consideration of the case by the jury.

6 For the reasons I shall explain I have concluded that:

(a) Dr Sullivan's evidence was relevant within the meaning of s 55 of the Evidence Act;

(b) it was evidence which he was qualified by his expertise to give; and

(c) it was not so unfair or prejudicial that it should have been excluded.

7 In accordance with the scheme of the Evidence Act, I will deal with the threshold matters of relevance and of Dr Sullivan's expertise before turning to the considerations relating to unfair prejudice.

8 The complainant was born in December 1974 and is the appellant's daughter. The offences were alleged to have occurred when the complainant was between 11 and 14 years of age and the appellant was between 46 and 50 years of age. By the date of his conviction, the appellant was 71 years of age. The Crown case was that the offences were constituted by the following conduct of which the complainant gave evidence.

9 When she was about 12 years old, the appellant approached the complainant while she was watching television at home. He pulled down his pants and attempted to push his penis into her mouth through her closed lips. He then placed his other hand behind her head and worked his penis into her mouth. He made thrusting motions with his hips before removing his penis and walking away (count 2 - incest).

10 When the complainant was about 13 years old and using the toilet, the appellant entered and asked to see her vagina. He told her that he would not leave until she showed him. The complainant pulled up her t-shirt while she was sitting on the toilet and the appellant looked at her (count 3 - gross indecency).

11 When she was about 13 years old, the complainant had taken $50 out of the appellant's wallet when he was not looking and hidden it in her room. When she was later watching television with her brother, the appellant walked into the lounge room and asked her whether she had taken the money. She denied it. Her father left the room and came back with the $50. He hit her across the face, causing her to fall to the floor. He picked her up by her arm and took her to his bedroom. He then closed the door, leaned over the bed, pulled her pants and underpants and anally penetrated her with his penis (count 4 - incest). She told him to stop and he responded by saying 'this is what you get for taking my money'. He moved his body with a back and forward motion for a minute or so before removing his penis and leaving the room.

12 When the complainant was about 13 years old and watching television at home the appellant came out of the shower and entered the lounge room. Nobody else was home. He hit her across the face. She landed on the floor. He then got on top of her and tried to pull her dress up. She struggled with him. He held her down with one hand moved her underwear to the side and placed his penis in her vagina (count 5 - incest). She asked him what he was doing and he responded by saying 'it's your fault that I'm doing this. It's the way you dress.' He then left the room.

13 On three occasions between 1 May 1988 and 10 December 1989, the appellant entered the bed of the complainant at night when her mother was in the shower. On each occasion, the complainant was awoken by the appellant getting on top of her. On each occasion, she struggled with the appellant as he tried to insert his penis into her vagina. He would cover her mouth with one hand and use the other hand to try to push her knees aside (counts 7, 8 and 10 - attempted incest). On the last occasion, which occurred when she was about 14, she fell out of bed and went to the corner of her room. The appellant told her to get back in the bed and she yelled 'No' at him. The complainant heard the shower stop running and the appellant left the bed and went to the door. He told her 'I'll get you tomorrow' and then left her bedroom.

14 The morning after this incident, the complainant rode her bicycle to the train station and took a train to her mother's workplace. The complainant told her mother that her father had been having sex with her. The complainant's mother returned home with her and questioned the appellant. He strongly denied having sex with the complainant. Her brother also participated in the discussion. The complainant's mother believed the appellant and her complaints were not discussed further.

15 The complainant first reported the offending to police about a month after speaking to a pastor in her church in 2008. She gave evidence that she also complained to her school friends and a boyfriend. When interviewed in July 2008 the appellant denied the allegations.

16 The defence case was that the offending had not occurred.

17 In turn, the defence relied on the fact that, after making complaint to her mother when she was around 14 years of age, the complainant continued to reside in the family home with the appellant until she was 18. The complainant then moved out of home but returned voluntarily the same year and continued to reside with the appellant and her mother, until moving out again at 23 years of age when she married. The complainant maintained a family relationship with the appellant and following the appellant's separation from the complainant's mother was the last of the family members to still have involvement with the appellant. The complainant ceased contact with the appellant in March or April 2008 following being 'born again' and becoming actively involved in her church. The defence put that her behaviour was not consistent with that of someone who had suffered the abuse which she alleged.

18 A large part of the questioning during the complainant's cross-examination at the committal focussed on behaviour which was said to be inconsistent with the truth of the complainant's evidence. The topics raised at the committal included the failure to yell out or scream at the time of sexual assaults; failures to tell her mother or brother of their occurrence; the fact the complainant remained living at home after the alleged assaults and then, having left home, maintained contact with her father; the fact that such contact included inviting him to her wedding and to the christening of her daughter and extended to a series of family functions at which, amongst other things, photographs were taken of the two together and gifts were exchanged between them.

19 As his Honour Judge Tinney, the trial judge, noted, the written defence response to the Crown case stated:

The accused will rely inter alia upon the following matters in defence of the allegations:

(a) the fanciful nature and detail of the claims;

(b) the complainant's behaviour towards the accused in the years following the period covered by the allegations.

20 In turn, counsel for the appellant confirmed at the trial that he intended to go to the same areas of evidence as were raised in cross-examination at the committal and would contend that the complainant's behaviour was inconsistent with the behaviour one would expect if the complainant was abused in the way she described.

21 The Crown sought to rebut the defence case as to counter-intuitive behaviour by calling expert evidence from Dr Sullivan that the complainant's behaviour was neither necessarily inconsistent with the allegations she made nor an abnormal response to offending of the type she described.

22 Such evidence could not establish that it was probable the complainant was telling the truth, but it could establish that her behaviour was not demonstrative of untruthfulness by reference to common or usual patterns of behaviour as asserted by the defence. In this sense, it could establish that the counter-intuitive behaviour complained of was of neutral significance. It could not demonstrate that the behaviour rendered it more or less likely that the offending had occurred as alleged.

23 As the New Zealand Law Reform Commission said in respect of the rationale for the admission of such evidence:[1]

Rather, the purpose of the evidence is educative: to impart specialised knowledge the jury may not otherwise have, in order to help the jury understand the evidence of and about the complainant, and therefore be better able to evaluate it.

Part of that purpose is to correct erroneous beliefs that juries may otherwise hold intuitively. That is why such evidence is sometimes called 'counter-intuitive evidence': it is offered to show that behaviour a jury might think is inconsistent with claims of sexual abuse is not or may not be so; that children who have been sexually abused have behaved in ways similar to that described of the complainant; and that therefore the complainant's behaviour neither proves nor disproves that he or she has been sexually abused. The purpose of such evidence is to restore a complainant's credibility from a debit balance because of jury misapprehension, back to a zero or neutral balance. This is similar to the use of expert evidence to dispel myths and misconceptions about the behaviour of battered women.

24 As the judge's ruling on the admissibility of Dr Sullivan's evidence records, counsel for the appellant at trial did not submit that the evidence proposed to be called from Dr Sullivan was irrelevant. Rather, counsel sought to challenge Dr Sullivan's qualifications to give the evidence and to exclude the evidence on this basis.[2]

25 The provisions of the Evidence Act themselves explicitly recognise that, in some circumstances, opinion evidence may be adduced which is based upon specialised knowledge of the impact of sexual abuse on children and their behaviour during and following the abuse and goes to issues of credibility.

26 Section 55 of the Evidence Act provides:

(1) The evidence that is relevant in a proceeding is evidence that, if it were accepted, could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding.

(2) In particular, evidence is not taken to be irrelevant only because it relates only to -

(a) the credibility of a witness; or

(b) the admissibility of other evidence; or

(c) a failure to adduce evidence.

27 Section 55 of the Evidence Act expressly contemplates that relevant evidence may be evidence which indirectly affects the assessment of the probability of the existence of a fact in issue in the proceedings. In particular, it will not be irrelevant only because it relates to the credibility of a witness.

28 Section 101A defines credibility evidence to include evidence which is relevant only because it affects the assessment of credibility of a witness or person.

29 Section 102 provides the general exclusionary rule that credibility evidence is not admissible ('the credibility rule').

30 The Crown in the present case relies upon s 108C, which provides an exception to the credibility rule.

(1) The credibility rule does not apply to evidence given by a person concerning the credibility of another witness if -

(a) the person has specialised knowledge based on the person's training, study or experience; and

(b) the evidence is evidence of an opinion of the person that -

(i) is wholly or substantially based on that knowledge; and

(ii) could substantially affect the assessment of the credibility of the witness; and

(c) the court gives leave to adduce the evidence.

(2) To avoid doubt, and without limiting subsection (1) -

(a) a reference in that subsection to specialised knowledge includes a reference to specialised knowledge of child development and child behaviour (including specialised knowledge of the impact of sexual abuse on children and their behaviour during and following the abuse); and

(b) a reference in that subsection to an opinion of a person includes, if the person has specialised knowledge of that kind, a reference to an opinion relating to either or both of the following -

(i) the development and behaviour of children generally;

(ii) the development and behaviour of children who have been victims of sexual offences, or offences similar to sexual offences.

31 As the High Court observed in Dasreef Pty Ltd v Hawchar,[3] the opinion rule contained in s 76 of the Evidence Act [4] directs attention to why the party tendering the evidence says it is relevant and, in particular, directs attention to the finding which the tendering party will ask the tribunal of fact to make. The same principles apply to the credibility rule and the operation of s 108C(1), which is relevantly in like terms to the exception to the opinion rule contained in s 79(1).

32 As both ss 79(2) and 108C(2) make clear, evidence as to the range of behaviours typical of victims reacting to sexual abuse might fall under these sub-sections. In the present case, the evidence which was permitted to be led from Dr Sullivan did not go to matters directly in issue such as whether, when and by whom the complainant was abused. The evidence was led to rebut an argument that the complainant's behaviour was harmful to her credit.[5] The evidence was not of the contentious nature put forward in HG v The Queen,[6] although it should be noted that in that case Gleeson CJ expressly contemplated that expert evidence might be led as to consistency of a complainant's behaviour with the occurrence of sexual abuse.[7] In CMG v The Queen, Harper JA, with whom Ashley and Weinberg JJA agreed, again contemplated the potential admission of evidence of the type here in issue: [8]

On the other hand, there are aspects of children's behaviour - such as that of child victims of sexual assault - that are not a matter of ordinary knowledge. Opinion evidence may therefore be given about child development and child behaviour (including the impact of sexual abuse on children, and their development and behaviour during and following abuse) once the conditions prescribed by the Evidence Act 2008, and in particular s 79 of that Act, have been met. I also note that, by s 108C, the credibility rule (which is found in s 102, and provides that credibility evidence about a witness is not admissible) does not apply to evidence given by a person concerning the credibility of another witness if the first (expert) witness meets the criteria set out in s 108C, and the court gives leave to adduce the evidence.

33 In giving his ruling as to the admissibility of the evidence, the trial judge said:

The dynamics of sexual abuse, the dynamics of incest are not matters of common knowledge to a jury. If they were, stances as demonstrated in the frequency of this style of cross-examination would be less common. The defence in this case seek to attack the credibility of [the complainant] by pointing to her behaviour, her behaviour said to be inconsistent.

Well, of course, they are free to do so, but the experience of the courts is that conduct such as that, that is staying in the home or not calling out, and the various other conduct that is raised in the course of the cross-examination of the witness is neither consistent nor inconsistent with the happening of the event which, as I understand it, is the effect of the evidence sought to be led. There is a range, a broad range, of responses and the dynamics are not as simple as might be suggested. The prosecution by the introduction of this evidence are seeking to neutralise what are said to be these erroneously held assumptions so that an assessment of the credibility of the complainant can proceed from a neutral position.

34 For present purposes, it is sufficient to say that Dr Sullivan's evidence as to patterns of victims' behaviour was relevant to rebut the defence case as to counter-intuitive behaviour on the complainant's behalf. The evidence bore upon the complainant's credibility as contemplated by s 55 in the specific manner contemplated by s 108C(2). It was capable of substantially affecting the assessment of the complainant's credibility as required by s 108C(1).

35 On the other hand, it is less obvious that evidence as to patterns of behaviour of a complainant's parent could substantially affect the credibility of a complainant, and hence fall within s 108C(1). It could not fall within the matters included for the avoidance of doubt in sub-s (2) unless it was interrelated with and of direct contextual relevance to evidence concerning the behaviour of child victims. Nor, it is important to note, could evidence as to the reasons for patterns of parental behaviour ordinarily be relevant to the credibility of a child complainant.

36 Section 388 of the Criminal Procedure Act 2009 ('the Criminal Procedure Act') (which might provide an alternative basis for the admission of Dr Sullivan's evidence) also implicitly raises the issue of the relevance of the evidence concerning the complainant's mother:

Despite any rule of law to the contrary, in a criminal proceeding that relates (wholly or partly) to a charge for a sexual offence, the court may receive evidence of a person's opinion that is based on that person's specialised knowledge (acquired through training, study or experience) of -

(a) the nature of sexual offences; and

(b) the social, psychological and cultural factors that may affect the behaviour of a person who has been the victim, or who alleges that he or she has been the victim, of a sexual offence, including the reasons that may contribute to a delay on the part of the victim to report the offence.

37 In turn, although the issue was not raised at trial nor the focus of complaint upon appeal,[9] the question arises whether Dr Sullivan's evidence went too far in addressing not only the psychological factors affecting the behaviour of the complainant, but also the psychological factors affecting the behaviour of the complainant's mother. The appellant submits that psychiatric evidence as to the behaviour of parents had no relevance to the issue of whether the complainant had in fact been abused. The real question is, rather, whether such evidence bore on the credibility of the complainant in a relevant way. The purpose of the evidence was simply to rebut an attack on credit. Nevertheless, when re-formulated by reference to this issue, the question of relevance of evidence relating to the complainant's mother remains a live one. In order to address this question it is necessary to say something in greater detail about Dr Sullivan's evidence.

38 Dr Sullivan presented his evidence to the Court by way of a report in respect of which he was cross-examined on a voir dire.

39 The trial judge excluded parts of the relevant portion of the report which sought to explain the complainant's personal reaction to the events in issue, but allowed general evidence as to behavioural responses to sexual abuse. Thus he admitted evidence as to the matters I have italicised in the relevant part of the report by Dr Sullivan set out below, but excluded the passages I have not italicised.

[25] You have asked me a range of questions about sexual abuse and memory, and I have addressed these.

[26] People subject to sexual abuse respond in a range of different ways which can range from falling in love with the abuser, ignoring abuse or exhibiting no outward change; to the other extreme of absconding or running away, self-harm, substance abuse and violence. The mother's response to her daughter's ([the complainant's]) disclosures of sexual abuse, as described, is not uncommon and relates to relational dynamics, cultural variables and the personality and character of the person making the disclosure. I would not consider [the complainant's] mother's denial that the abuse occurred to be uncommon.

[27] [The complainant] describes clearly that she was financially dependent upon her parents, unable to leave and that there were cultural expectations of remaining together as a family. She described that once her mother did not believe her, she sought to reduce attention to herself and remained living in the family home but vigilant towards her father and, by her account, cold towards him.

[28] Children subject to sexual abuse from their parents as a child are often intimidated or fearful that they will be harmed or others will be harmed, and the offending often carries an implicit or explicit threat that this will happen, that the person will not be believed and that harmful consequences will befall the child. Consequently, it is certainly not uncommon for sexually abused children to remain in the family home and to be fearful that disclosure will result in adverse consequences.

[29] You have asked me to address the relationship between deliberate self-harm and childhood sexual abuse. It is often considered that there is a causal association between experiences of childhood sexual abuse and self-harm. However, it should be remembered that sexual abuse is statistically common and self-harming behaviour including cutting is also statistically common. What is often clear is that feelings of self-loathing induced by being sexually abused may be partially relieved by self-harming behaviour.

[30] A delay in ceasing contact with an abusing parent may well be because of fear of adverse consequences, a desire not to split up the family or uncertainty whether the complaint will be believed. This is particularly understandable given that [the complainant's] earlier disclosure to her mother had not been believed.

[31] The sequence of events after which she stopped seeing her father were also, by [the complainant's] account, associated with her writing a letter to her father explaining her actions. Such actions may well be consistent with the complex emotional feelings associated with making a complaint to the police, a course of action which takes both courage and much consideration. It is likely that [the complainant] engaged in some deliberation before taking this course of action and had developed a rationale for the way in which she was doing it.

[32] Ambivalence about the person who has engaged in sexual abuse is very common. Given a child's emotional development, experiences of sexual abuse may be associated with confused feelings such as sexual arousal, love and guilt. Children subject to sexual abuse may feel, or be made to feel, that it is their failings which have led to the sexual abuse occurring or even be made to expect that it is normal. Consequently, people who have been sexually abused do not uniformly hate the abuser and may have a range of conflicted feelings involving often contrasting emotions, which they struggle to make sense of.[10]

40 The content and basis of each of these passages had been amplified and explained during cross-examination upon the voir dire.

41 When Dr Sullivan gave evidence to the jury he first addressed the question why a child may not call out for help when sexual offending is being committed against him or her while other persons are close by. He stated that the research literature indicates that there are a range of responses to abuse and that they vary according to the individual concerned and in particular their family context and individual resilience. He stated of family context in particular:

And finally there are situational factors which relate to the family context, how strong communication is between family members, whether a child feels supported by its parents or feels safe, whether the child is subject to a range of other abusive behaviours such as violence, corporal punishment or emotional abuse, which impact on their ability to mount an effective response to abuse. So the summary is that individuals, based upon their developmental age and the sort of person they are and the sort of family they're in, will exhibit different responses to situations of perceived threat.

42 Once Dr Sullivan stated that the question of whether a child feels supported by his or her parents is directly relevant to the nature of the child's response to sexual abuse, it followed that the question of common parental reactions to complaints about sexual assault was intertwined with Dr Sullivan's evidence as to common behavioural responses of victims. Thus, when asked next about common parental responses to complaints, Dr Sullivan's answer went directly to this nexus (emphasis added):

It's similar to my previous answer. It depends upon the individual, their developmental age, how supported they feel in their family, whether they have trusted people that they can go to, but certainly disclosures can be made at the time subsequently to a figure of trust and also to other people such as teachers or counsellors, and disclosures sometimes made in sexual abuse cases are interestingly often retracted by children. The interesting factor about the likelihood of particular emotional outcomes, so psychological disturbance or the development of mental disorder or substance abuse, is strongly associated with perceived maternal support, so that is if a person who is subject to sexual abuse perceives their mother as supportive, they're less likely to suffer any form of emotional or mental disturbance subsequently than someone who doesn't perceive maternal support, so issues of disclosure are very profound in terms of whether a person is able to cope or not.

43 Dr Sullivan then went on to explain why a parent might not accept a complaint of sexual abuse, and referred to the possibility that the parent may be strongly invested in a relationship with their partner rather than a child.

44 Dr Sullivan was then asked why a child victim of sexual abuse might persist in a relationship with an abuser and said (emphasis added):

Children subject to childhood sexual abuse report it as a very conflicted emotional situation. They report a mixture of emotions including hatred, fear, love, in some cases sexual arousal. It's a very confusing experience, and depending upon the developmental age of the child they will make different sense of it, so just once more, to think about that, a three year old will potentially not experience some things as harmful in the same way that a child who is older will. They won't have the sophistication or understanding of what the boundaries are between appropriate and inappropriate behaviour, even things like nudity. An older child will experience a range of emotions which can include the same sorts of emotions, but they have a little more emotional sophistication in dealing with those emotions. But a child in that situation, once more, similar to what I mentioned of a mother to whom a disclosure is made, is in a situation where they're powerless because they're a child or they're less powerful, and they have a range of choices to make which might include things like running away from home, telling someone, fighting back, not fighting back. It's very difficult to determine, and once more it relies upon that combination of how supported a child feels, what the child is like as an individual and what their developmental age is.

45 It can be seen that Dr Sullivan's evidence as to the behavioural responses of victims of sexual abuse referred to contextual considerations relating to the behavioural responses of the victim's mother in two ways. First, the evidence indicated that the response of the mother was, in itself, a significant factor affecting the victim's response and, secondly, a victim's reaction to sexual abuse may be affected in the same way as a parent to whom disclosure is made by the investment they otherwise have in the family relationship.

46 Dr Sullivan went on to answer a series of questions about the significance to the victim's reactions of the fact that the abuser may be a parent. He described the significance of conflicted emotions and cognitive dissonance.

47 He was then asked whether it was a common or uncommon feature for persons who have been sexually abused by a parent to continue a relationship with the parent after abuse. He said this depended on developmental age and individual resourcefulness.

48 Dr Sullivan was also asked what effect the fact that a report of abuse was ignored and not believed by the other parent would have on a victim's likelihood of continuing in a relationship with the abusing parent. Dr Sullivan said:

Once more, it depends upon the social circumstances. If a child is quite isolated and doesn't have other people to rely upon, then sometimes that's where a disclosure might finish. If the disclosure is disbelieved, the child becomes - feels helpless to effect any change in their life. If you recollect your own development, you'll know that there is a stage of which you cease to look at your parents as the main objects in your universe and you start to look at your peer group. So again, at the developmental age of which abuse occurs, some children will rely upon their parents as being omnipotent, that is all powerful and able to - they will say that if my parent won't do anything, then nothing can be done and in other circumstances, a child with different resilience, different individual strengths and a different sense of being supported, would go elsewhere and make other disclosures. They would say, well if my parent won't listen to me, I'll tell the school counsellor or tell the priest, I will tell my next door neighbour. It is very dependent upon those range of individual circumstances.

49 Dr Sullivan then went on to give evidence about repressed memory and the lack of effect either of the condition of scleroderma or cortisone medication upon memory.

50 Following this evidence in chief, Dr Sullivan was cross-examined about the last mentioned aspects of his evidence and about notes he took from the complainant concerning the history of the events in issue. He was not, however, cross-examined about his evidence concerning behavioural responses to sexual abuse.

51 In my view, the evidence relating to parental response and, in particular, maternal response to complaints by a child of sexual abuse was sufficiently interrelated with and directly relevant to the evidence of potential responses by a victim of sexual abuse as to fall within s 108C of the Evidence Act and s 388 of the Criminal Procedure Act.

52 Accordingly, the judgment of trial counsel was correct and the evidence of Dr Sullivan (including the matters referred to at [26] of his report) did not fall to be excluded on the grounds of relevance. It was evidence which, in terms of s 108C, could substantially affect the assessment of credibility of the complainant in respect of matters which the defence put squarely in issue.

53 It is further submitted that the evidence was so general that it could not be of assistance in resolving the actual issues to be decided by the jury. I do not accept that this was so. The evidence went directly to rebut the defence assertion that the complainant's behaviour should be regarded as counter-intuitive in terms of ordinary patterns of behaviour if her complaints were true. It did so by addressing the question whether behaviours of the type in issue can be regarded as atypical or unusual. Such evidence was necessarily general in scope, going as it did to the question of normal behaviour. More specific evidence was deliberately excluded by the judge.

54 It is next submitted that the evidence was irrelevant because it did not address the issue of the complainant as an adult maintaining a relationship, being essentially focussed on the behaviour of children. The complainant remained a child for a significant period both during and after the offending and it was open to the jury to regard Dr Sullivan's evidence as contextually relevant to their assessment of her credibility. No cross-examination was directed to Dr Sullivan in respect of the issue identified. Moreover, the issue goes to the extent of relevance, not relevance as such.

55 It was next submitted that Dr Sullivan's evidence was not materially probative because it was based upon anecdotal assertions of patients in the course of giving histories to him. It is submitted that Dr Sullivan's opinion rested on uncritical repetition of the untested assertions of an unrepresentative group who were largely male and predominantly offenders. The criticism now made goes essentially to the question of whether Dr Sullivan's opinion was 'based upon scientific study', a matter going not to its relevance but to the question of whether it was an expert opinion in the true sense. This issue is raised by a separate ground of appeal to which I shall shortly turn. If it was expert in the relevant sense, the basis of Dr Sullivan's opinion was a matter for the jury to evaluate. The criticism raised goes to weight, not relevance. Once again, no cross-examination was directed to these matters before the jury.

56 It is next submitted that the evidence was not relevant because it was substantially comprised of unexplained ipse dixit assertions which provided the jury with no basis by which to assess their validity and to apply them to the facts of the case. Once again, this criticism goes not to relevance but the basis of the opinions in issue which is raised directly by the next ground of appeal. In short, however, Dr Sullivan did explain the basis of his opinions. He was cross-examined at length about such basis on the voir dire but counsel elected not to pursue such cross-examination before the jury. A deliberate forensic choice was made in this regard and the appellant cannot now complain that matters were not explored in cross-examination which could have been.

57 In order to be admissible under s 108C of the Evidence Act, Dr Sullivan's evidence was required to be opinion evidence wholly or substantially based upon specialised knowledge derived from his training, study or experience. The same question arises under ss 76 and 79 of the Evidence Act, which govern expert evidence generally. The Australian Law Reform Commission in Report 102 stated that s 108C was intended:

... to clarify that evidence can be led under the section in relation to the development and behaviour of children generally and the development and behaviour of victims of child sexual assault. This clarification is designed to overcome a demonstrated reluctance of courts to accept that the development and behaviour of children is a matter of specialised knowledge outside the general knowledge of the community.[11]

58 The relevant concept of specialised knowledge was analysed by Heydon JA in Makita (Australia) Pty Ltd v Sprowles:[12]

In short, if evidence tendered as expert opinion evidence is to be admissible, it must be agreed or demonstrated that there is a field of 'specialised knowledge'; there must be an identified aspect of that field in which the witness demonstrates that by reason of specified training, study or experience, the witness has become an expert; the opinion proffered must be 'wholly or substantially based on the witness's expert knowledge'; so far as the opinion is based on facts 'observed' by the expert, they must be identified and admissibly proved by the expert, and so far as the opinion is based on 'assumed' or 'accepted' facts, they must be identified and proved in some other way; it must be established that the facts on which the opinion is based form a proper foundation for it; and the opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached: that is, the expert's evidence must explain how the field of 'specialised knowledge' in which the witness is expert by reason of 'training, study or experience', and on which the opinion is 'wholly or substantially based', applies to the facts assumed or observed so as to produce the opinion propounded. If all these matters are not made explicit, it is not possible to be sure whether the opinion is based wholly or substantially on the expert's specialised knowledge. If the court cannot be sure of that, the evidence is strictly speaking not admissible, and, so far as it is admissible, of diminished weight. And an attempt to make the basis of the opinion explicit may reveal that it is not based on specialised expert knowledge, but, to use Gleeson CJ's characterisation of the evidence in HG v The Queen,[13] on 'a combination of speculation, inference, personal and second-hand views as to the credibility of the complainant, and a process of reasoning which went well beyond the field of expertise'.

59 The propositions stated in Makita are not to be taken as a gloss upon the statutory provision, which is of universal application. Nevertheless, they provide a convenient structure for the purposes of the argument in this appeal. In Dasreef v Hawchar, the High Court said:[14]

It should be unnecessary, but it is nonetheless important, to emphasise that what was said by Gleeson CJ in HG (and later by Heydon JA in the Court of Appeal in Makita (Australia) Pty Ltd v Sprowles) is to be read with one basic proposition at the forefront of consideration. The admissibility of opinion evidence is to be determined by application of the requirements of the Evidence Act rather than by any attempt to parse and analyse particular statements in decided cases divorced from the context in which those statements were made. Accepting that to be so, it remains useful to record that it is ordinarily the case, as Heydon JA said in Makita, that 'the expert's evidence must explain how the field of "specialised knowledge" in which the witness is expert by reason of "training, study or experience", and on which the opinion is "wholly or substantially based", applies to the facts assumed or observed so as to produce the opinion propounded'. The way in which s 79(1) is drafted necessarily makes the description of these requirements very long. But that is not to say that the requirements cannot be met in many, perhaps most, cases very quickly and easily. That a specialist medical practitioner expressing a diagnostic opinion in his or her relevant field of specialisation is applying 'specialised knowledge' based on his or her 'training, study or experience', being an opinion 'wholly or substantially based' on that 'specialised knowledge', will require little explicit articulation or amplification once the witness has described his or her qualifications and experience, and has identified the subject matter about which the opinion is proffered.

60 Dr Sullivan is a Consultant Forensic Psychiatrist, Assistant Clinical Director, Victorian Institute of Forensic Mental Health, and Adjunct Senior Lecturer at the School of Psychology and Psychiatry at Monash University.

61 It is not in dispute that, in general terms, psychiatry is field of specialised knowledge constituted by the medical science and speciality which deals with the origin, diagnosis, prevention and treatment of mental and emotional disorders and by extension of many problems of personal adjustment.[15]

62 The appellant submits, first, that it was not established in accordance with the second factor identified in Makita that Dr Sullivan had expertise in the specific identified aspect of the field relevant to the evidence he sought to give, as opposed to general expertise in forensic psychiatry. Satisfaction of the statutory test by reference to this factor is a matter of fact and degree.[16]

63 In my view, Dr Sullivan did demonstrate that he had specialised knowledge of the effects of sexual abuse upon children and the development and behaviour of child victims during and following abuse.

64 He so qualified himself by reference to his professional experience and his awareness and understanding of relevant research literature.

65 He stated that his work as a forensic psychiatrist has been strongly influenced by the work of Professor Paul Mullen, who was his mentor and who has, since the 1990s, undertaken a series of studies into the effects of childhood sexual abuse upon victims with which he was familiar. He said further he was familiar with the research literature relating to this issue. He attends conferences, reads the American journal 'Sexual Abuse' and a range of other relevant publications. He has a special interest in sexual offending issues which overlaps with issues relating to the effects of sexual abuse upon children. He has also read a range of references related not only to the experience of childhood sexual abuse but the consequences of such abuse. The most relevant texts in his view were Evidence Based Perspectives on Childhood Sexual Abuse by David Ferguson and Paul Mullen, together with A Source Book of Childhood Sexual Abuse by David Finkelhor.

66 He relied upon his general reading in the area with respect to studies comparing children affected by sexual abuse with a peer group at the time of sexual offending, and studies which rely on the subsequent reports of adults compared with peer groups. Thus on the voir dire Dr Sullivan said in part:

The features that I've mentioned there, in particular the negative features, features where a person doesn't evidence significant behavioural disturbance or mental disorder at the time, are consistent with the literature which reports that between 20 and 40 per cent of people who have been sexually abused do not report behavioural or emotional disturbance. So there's a significant minority of people who do not go on to develop more severe mental disorders. It's an interesting finding because I think the intuition of most people is that people who are sexually abused manifest a range of emotional difficulties including depression, self-harm, substance abuse, difficulties in relationships, and although that is certainly true that they have an increased rate compared to the general population, factors such as an individual's resilience, the age at which the abuse is purported to have occurred, and dynamics about the family of origin are perhaps relevant in determining an individual response to an individual situation.

67 He also said part of his training was in critical appraisal of research papers and that as a person involved in both research and treatment, he read the professional literature more than a number of other psychiatrists would.

68 Dr Sullivan also relied on his professional clinical experience. He stated that he had had the opportunity to assess, at a conservative estimate, 5,000 patients. He said he:

assessed predominantly offenders with a particular interest in sexual offenders and due to the prevalence of childhood sexual abuse, it's a routine part of the psychiatric examination that we would take a detailed history from the person of any alleged abuse that they report occurred in childhood, the nature of that abuse, the psychological consequences of that abuse ...

69 In cross-examination on the voir dire, Dr Sullivan was asked about the evidence he specifically relied on for the purposes of [26], [28], [30] and [32] of his report. He stated that his opinions were based both upon relevant research and his own clinical experience. The opinions expressed in [26] and [32] were predominantly based upon research and the opinions expressed in [28] and [30] were predominantly based upon clinical experience.

70 In my view, Dr Sullivan's evidence clearly identified and explained the specific area of specialised knowledge upon which his opinions were substantially based, namely a particular aspect of psychiatry in respect of which he had acquired expertise.

71 It is next submitted on behalf of the appellant that Dr Sullivan's evidence did not establish the facts or assumptions upon which it was based.[17] This submission must also fail. Dr Sullivan explained the basis of his opinions and that basis was capable of rational assessment by the jury. It is now submitted that Dr Sullivan's opinions were, in substantial part, based upon anecdotal case histories and that such histories must necessarily be subject to limitations as a basis for ascertaining empirical facts. There is, however, an obvious problem in addressing why complainants do not cry out or necessarily complain (whether at all or in a continuing fashion) by way of a contemporaneous or prospective study. The lack of complaint itself precludes immediate ready identification of the relevant cohort group. The issue raised goes to weight, not admissibility of the evidence.

72 Next, it is submitted that Dr Sullivan could not demonstrate how his expertise in psychiatry bears upon the information he referred to so as to produce his opinion.[18] In Farquharson, the Court cited with approval the statement of the relevant principle in Cross on Evidence:

the expert's evidence must explain how the field of specialised knowledge in which the witness is expert by reason of training, study or experience, and on which the opinion is wholly or substantially based, applies to the facts assumed so as to produce the opinion propounded.[19]

73 This submission should also be rejected. Dr Sullivan explained that it was a function of his professional training that he was able to assess and critically respond to the academic literature to which he referred so as to express his opinion. He further explained how the process of taking a huge number of individual patient histories as part of his psychiatric practice further informed his expertise.

74 In Makita, Heydon JA cited with approval the following statement by Lord President Cooper in Davie v Lord Provost, Magistrates and Councillors of the City of Edinburgh:[20]

Expert witnesses, however skilled or eminent, can give no more than evidence. They cannot usurp the functions of the jury or Judge sitting as a jury, any more than a technical assessor can substitute his advice for the judgment of the Court ... Their duty is to furnish the Judge or jury with the necessary scientific criteria for testing the accuracy of their conclusions, so as to enable the Judge or jury to form their own independent judgment by the application of these criteria to the facts proved in evidence. The scientific opinion evidence, if intelligible, convincing and tested, becomes a factor (and often an important factor) for consideration along with the whole other evidence in the case, but the decision is for the Judge or jury. In particular the bare ipse dixit of a scientist, however eminent, upon the issue in controversy, will normally carry little weight, for it cannot be tested by cross-examination nor independently appraised, and the parties have invoked the decision of a judicial tribunal and not an oracular pronouncement by an expert.

75 In the present case, the basis of Dr Sullivan's opinions was tested extensively in cross-examination on the voir dire. In particular, the scientific basis of his opinions and the way in which they were founded in specialised knowledge was explored.

76 Thus in cross-examination on the voir dire, counsel for the appellant explored among other things:

(a) the limitations that the nature of his clinical practice might impose upon the conclusions he could draw from data derived from it;

(b) the lack of statistical rigour in drawing conclusions from anecdotal evidence, however extensive; and

(c) the inability of the appellant and, in turn, the jury to check or verify the developmental histories upon which Dr Sullivan relied to express conclusions about behavioural patterns.

77 Counsel for the appellant elected not to repeat this process before the jury. Further, the opinions now in issue were not even challenged in cross-examination before the jury. It was not suggested to Dr Sullivan either that the opinions he expressed were incorrect in fact or that he could not justify them. The failure to challenge the scientific basis of Dr Sullivan's opinions reflects the reality that they had been demonstrated to be well-founded upon the voir dire hearing.

78 In giving leave to admit Dr Sullivan's evidence, the trial judge expressly considered the application of ss 135 and 137 of the Evidence Act.[21] He expressly considered the reliability of the evidence despite doubt as to the relevance of that factor upon the authorities as they then stood.[22]

79 I am not persuaded that the probative value[23] of Dr Sullivan's evidence was outweighed by the danger of unfair prejudice to the appellant.

80 For the reasons I have already explained, I am not persuaded that it has been demonstrated that the evidence was inherently unreliable. It was credible opinion evidence based upon an evidentiary basis that was not ultimately challenged before the jury. The weight to be given to the evidence was capable of rational evaluation by the jury.

81 Further I do not accept that the evidence carried with it a material danger of unfair prejudice. The trial judge did not err in the approach he took to this consideration. His ruling stated in part:

I see no danger at all of any unfair prejudice under s 137. As I have indicated, unfair prejudice is not defined in the Act, but it is clear from the materials, including materials in Odgers, that it is intended to cover evidence which might introduce an adverse or for that matter irrational consideration, or cause jurors to accord to other evidence a higher probative value than is deserving.

It follows that evidence will be unfair if there was a real risk that it would be misused by the jury in some unfair way. It is equally clear that evidence will not be unfairly prejudicial merely because it increases the likelihood of an accused person being convicted. The danger referred to in the provisions cannot be merely a risk or a possibility. There must be a real danger of unfair prejudice arising in the event of the admission of the evidence, that is a real risk that the evidence will be misused by the jury in some fashion, and that the risk would exist notwithstanding directions of law given to them by the trial judge, see Shamouil.

Here the jury will be properly instructed as to their function and the fact that they are the judges of the facts. They will be properly instructed in that sense and will understand, as clearly as can be understood, that they are not bound to accept any evidence from any witness, whether expert or otherwise.

82 The relevant concept was encapsulated by McHugh J in Pfennig:[24]

If there is a real risk that the admission of such evidence may prejudice the fair trial of the criminal charge before the court, the interests of justice require the trial judge to make a value judgment, not a mathematical calculation. The judge must compare the probative strength of the evidence with the degree of risk of an unfair trial if the evidence is admitted. Admitting the evidence will serve the interests of justice only if the judge concludes that the probative force of the evidence compared to the degree of risk of an unfair trial is such that fair minded people would think that the public interest in adducing all relevant evidence of guilt must have priority over the risk of an unfair trial.

83 Dr Sullivan's evidence did not preclude the making of a submission on behalf of the appellant that the complainant's failure to cry out in the particular circumstances of her case at the time of the alleged assaults and the manner in which she remained in a family relationship with the appellant thereafter raised doubts as to her credibility. Dr Sullivan's evidence simply provided a context which explained the range of common behavioural responses to sexual abuse, within which the jury could assess the evidence relating to the complainant.

84 In turn, the jury were well able to evaluate the way in which Dr Sullivan's generalised evidence might be said to bear on the facts of the case, including such matters as the fact that the complainant continued in a family relationship with the appellant when she was an adult and not simply for the initial period after the alleged offending when she was a child.

85 Counsel for the appellant draws particular attention to the fact that, at one point, Dr Sullivan identified a potential link between the failure of mothers to act on allegations of sexual abuse by their children and the possibility that such mothers were victims of domestic abuse by the same person. Dr Sullivan did not say, and there was no suggestion, that this was the situation in the present case. Dr Sullivan simply referred to this possibility in the range of behavioural explanations for the outcomes he described. Similarly, the fact that at one point Dr Sullivan said that one reason a victim might not protest during an act of abuse was that the victim had been subjected to other abuse such as violence, again, did no more than identify an aspect of the complexity of responses to sexual abuse. Although it will be recalled that, in the present case, the complainant's evidence is that she was physically abused by the appellant as well as sexually abused, Dr Sullivan did not express a view as to the applicability of this potential link in the present case.

86 Lastly, it is submitted on behalf of the appellant that, given Dr Sullivan's standing and authority, the jury was likely to have regarded his evidence as the basis for concluding the complainant's behaviour was unremarkable. It is further submitted that the evidence could not properly support such a conclusion. As I have sought to explain, the evidence could properly support such a conclusion, but the support was constituted by no more than an understanding of the behavioural context in which to assess the particular circumstances of the case as the jury found them. What the evidence did not seek to do, and what it could not do, was establish that the complainant's behaviour was positively confirmatory of sexual abuse.

87 It is further submitted that the danger created by the whole of this evidence 'was exacerbated by the learned trial judge endorsing it in the charge as essentially uncontentious.' As I have said, the evidence was not challenged in cross-examination and his Honour was entitled to approach the question in the manner that he did. No relevant exception was taken to the charge.

88 Ultimately, I am not persuaded that Dr Sullivan's evidence did more than provide an informed context in which to assess the whole of the complainant's evidence as to her reaction to the offending and her subsequent conduct. In my view, the appeal should be dismissed. Self-evidently, however, a different view of the consequences of ss 108C, 135 and 137 may result with respect to evidence of the type which his Honour the trial judge properly excluded, namely expert evidence as to the specific reactions of an alleged victim of sexual abuse.[25]

89 The appellant contended that the evidence of Dr Sullivan was inadmissible as it had not been shown to be based upon any specialised knowledge which he

possessed, that his field of expertise could not support his opinion and that such expertise and his opinions were not relevant to the case. We have had the benefit of reading the reasons in draft of Osborn JA and agree that these contentions cannot be sustained.

90 Dr Sullivan explained and drew upon the particular aspect of his specialised field of knowledge that was relevant to the opinion evidence he sought to give. He identified the basis for his opinions and how his specialised knowledge informed his opinions. He furnished the jury with the necessary scientific criteria enabling them to independently evaluate the accuracy of his opinions. His opinions were relevant to the issue of the behaviour of the complainant.

91 The opinion evidence concerning common parental rejection of a child's complaint and whether the child felt supported bore upon common behavioural responses of victims. The association of the issue of whether parental disbelief was not uncommon on the one hand, and the factors which lead to it on the other was initially made in one of the passages in Dr Sullivan's written report which was ruled to be admissible. Further, during his evidence Dr Sullivan explained why a parent might not accept a complaint of sexual abuse and referred to the possibility that the parent may be strongly invested in a relationship with their partner rather than a child. The evidence was given in direct response to the question whether Dr Sullivan was aware of circumstances in which a victim has reported sexual abuse to a parent who has done nothing in response. Dr Sullivan referred to circumstances that he had encountered and the 'range of pressures upon people to believe or not to believe a child.' He identified some of those pressures, including parental investment in the relationship with their partner and provided an explanation of that kind of pressure. The questioning then moved to another topic.

92 In this case no objection was taken at trial to the evidence about the factors bearing upon parental disbelief on the ground of relevance, and even on the appeal, relevance was not the focus of complaint about this evidence. As Osborn JA has observed, the factors which bear upon parental disbelief were interwoven with the evidence as to whether parental disbelief was not uncommon and how victims might commonly react to a rejection of their assertions. Whilst at a general level evidence about reasons for parents' rejection of their child's claim may be interwoven with children's common behavioural responses, it is the opinion evidence concerned with the common effects of rejection on a child's state of mind, not the parents' reasons for non acceptance of the child's assertion, which is germane to the victim's credibility. Had the expert evidence that parental disbelief was not uncommon been challenged, then greater examination of the range of reasons for parental disbelief could have been justified in order to meet that challenge.

93 There are some additional observations we would make concerning the admissibility of expert evidence bearing upon the credibility of witnesses in a criminal trial.

94 Section 37E of the Evidence Act 1958 had provided that expert evidence, based upon specialised knowledge, acquired through training, study or experience could be given concerning sexual offences and the social, psychological and cultural factors that might affect the behaviour of a person who has been the victim of such an offence including the reasons that may contribute to a delay on the part of the victim to report the offence.[26] Section 388 of the Criminal Procedure Act essentially replicated the former provision. Although s 388 is similar to s 79 of the Evidence Act, it is not limited to specialised knowledge concerning child development and behaviour and includes opinion evidence as to any factors that may contribute to delay in a victim reporting a sexual offence.

95 The evidence of Dr Sullivan was, as Osborn JA states, admissible under s 108C of the Evidence Act as an exception to the credibility rule. Where the basis for admissibility of such evidence is the Evidence Act, and it becomes apparent that the evidence is relevant only to the credibility of the complainant, the evidence could only be admitted by leave of the trial judge pursuant to s 108C.[27] Hence in ISJ v The Queen[28] this Court stated that whatever the gateway by which the evidence is sought to be admitted, once it is plain that the sole use of the evidence is directed to the credit of the witness, the preconditions to admissibility laid down under pt 3.7 of the Act must be satisfied. But s 388 of the Criminal Procedure Act may apply 'despite any rule of law to the contrary.' We have not heard argument as to the way in which s 108C and s 388 might interact. Hence we express no concluded view as to whether there may be circumstances where evidence could be admitted pursuant to s 388 where leave to do so under s 108C would be refused. As presently advised, whichever provision is relied upon, it appears that ordinarily the decision as to admissibility is likely to be the same.

96 The appellant also contended that given Dr Sullivan's standing and authority, the jury was likely to have attached undue weight to his opinion and concluded that the complainant's behaviour was unremarkable. It was submitted that his evidence should have been excluded pursuant to s 137 of the Evidence Act.[29]

97 In the recent decision of Dupas v The Queen[30] this Court discussed the exclusion of expert evidence under the common law 'Christie discretion.' Section 137 was regarded as imposing the same test. As to the position at common law, it was said in the joint judgment :

Expert evidence has often been excluded in the exercise of the discretion where the trial judge was dissatisfied with its reliability and probative value. Though modern attitudes towards expert evidence may be less exclusionary than in the past, it remains important - as Dawson J stated in Murphy v The Queen - to recognise the dangers of wrongly admitting it:

The admission of such evidence carries with it the implication that the jury are not equipped to decide the relevant issue without the aid of expert opinion and thus, if it is wrongly admitted, it is likely to divert them from their proper task which is to decide the matter for themselves using their own common sense. And even though most juries are not prone to pay undue deference to expert opinion, there is at least a danger that the manner of its presentation may, if it is wrongly admitted, give to it an authority which is not warranted.

At common law there was a requirement that the expertise rested upon a 'body of knowledge or experience which is sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience'. The expert must provide the criteria enabling evaluation of the validity of the expert conclusions. There continues to be a focus on the extent to which the expert's assumptions, methodology and conclusions are disclosed as part of the expert's reasoning. The absence of adequate disclosure of the expertise or the reasoning will often bear on weight rather than admissibility.

It is unnecessary to refer to the detailed observations of Heydon JA in Makita but, to the extent that the expert does not satisfactorily demonstrate that the opinion is based upon 'specialised knowledge' in which the witness is expert, or does not sufficiently identify the facts upon which the opinion is 'wholly or substantially based,' the evidence so far as it is admissible will be of diminished weight. Where the sufficiency of such matters is in doubt, the reliability of the opinion is brought into question, with the risk that the expert evidence will be given disproportionate weight by the tribunal of fact.

This is an important consideration bearing upon discretionary exclusion. Hunt J in R v Elliot stated the trial judge's duty in these terms:

If scientific testing in the particular case is unreliable or if it has a tendency to produce a misleading or confusing impression to the jury or if the weight to be afforded to the result is so minimal as to preclude the jury being satisfied beyond reasonable doubt that the Crown has established the fact which it seeks to prove, then clearly I have a duty to exclude it from the jury - whether it is a result of ruling that the evidence is inadmissible or whether it is excluded in the exercise of my discretion.[31]

98 These cautionary observations remain apposite where, the evidence having been considered admissible pursuant to s 79 or s 108C of the Evidence Act or s 388 of the Criminal Procedure Act, a question arises as to the reliability of that evidence. The trial judge may have to undertake the evaluation required by s 137 to determine whether the probative value of the evidence is outweighed by the degree of prejudice that may flow from the admission of the evidence. Where for some reason the opinion may be viewed as unreliable, the weight that the jury may reasonably assign to the evidence, may be diminished.[32] As is apparent from the reasons in Dupas, when s 137 is enlivened, the trial judge is required to assess the extent of any risk that the evidence will receive more weight than it deserves. Expert opinion evidence may give rise to such a danger.

99 The general evidence of Dr Sullivan did not raise such concerns. The jury was able to evaluate the basis for his opinion and the extent to which it could rationally assist them in assessing the credibility of the complainant.[33] No basis for exclusion of the evidence under s 137 has been made out.

100 We should say before leaving the question of expert evidence bearing upon the credibility of a complainant that one would not ordinarily expect an expert to be asked to express an opinion concerning the complainant's actual behaviour after the alleged offending conduct or the reasons of a parent in the case before the court for not accepting the complainant's claim or the complainant's actual reaction to the rejection of her claim. These are questions which are within the jury's province to resolve. The occasion should be relatively rare where an expert should be invited to express an opinion as to the actual behaviour of the victim or the victim's parent and whether it advanced the probabilities of a fact in issue. Where a party seeks to have an expert go so far, the obligation of the trial judge under s 137 of the Evidence Act to exclude evidence if its probative value was outweighed by its prejudice may assume greater significance. Such questions did not arise in this trial.

101 We agree with Osborn JA that the appeal should be dismissed.

[1] New Zealand Law Reform Commission, Evidence: Evidence Code and Commentary, Report No 55 (1999) vol 2, 67 [C110] - [C111] (emphasis in original).

[2] The trial judge said, in his ruling: 'Mr Thomas does not submit that such evidence as this, if led from the correct expert, could not be led.' He further said: 'There has been no argument that has been addressed to me going to the issue of relevance.'

[3] [2011] HCA 21; (2011) 243 CLR 588, 602 [31].

[4] Sections 76 and 79 of the Evidence Act 2008 provide:

Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed.

79 Exception - opinions based on specialised knowledge

(1) If a person has specialised knowledge based on the person's training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge.

(2) To avoid doubt, and without limiting subsection (1) -

(a) a reference in that subsection to specialised knowledge includes a reference to specialised knowledge of child development and child behaviour (including specialised knowledge of the impact of sexual abuse on children and their development and behaviour during and following the abuse); and

(b) a reference in that subsection to an opinion of a person includes, if the person has specialised knowledge of the kind referred to in paragraph (a), a reference to an opinion relating to either or both of the following -

(i) the development and behaviour of children generally;

(ii) the development and behaviour of children who have been victims of sexual offences, or offences similar to sexual offences.

[5] Cf Bellemore v Tasmania [2006] TASSC 111; (2006) 170 A Crim R 1 (Crawford J, 20 [52]; Blow J, 63 [204]).

[6] [1999] HCA 2; (1999) 197 CLR 414.

[7] Ibid 428 [41]. (See also Gaudron J, 432-433 [51]-[65]).

[8] [2011] VSCA 416, [17] (citation omitted).

[9] This evidence was not one of the enumerated complaints as to relevance in paragraph [7] of the written Further Submissions on behalf of the Appellant.

[10] Report of Dr D Sullivan dated 23 May 2011.

[11] Australian Law Reform Commission, Uniform Evidence Law, Report No 102 (2005) 422-423 [12.122].

[12] [2001] NSWCA 305; (2001) 52 NSWLR 705, 743-744 [85] ('Makita').

[13] [1999] HCA 2; (1999) 197 CLR 414, 428 [41].

[14] [2011] HCA 21; (2001) 243 CLR 588, 604 [37] (citations omitted; emphasis added).

[15] Cf Blakiston's Gould Medical Dictionary, 3rd Edition.

[16] R v Farquharson [2009] VSCA 307, [79] ('Farquharson').

[17] Reliance is placed upon the third and fifth of the propositions stated in the passage from the judgment of Heydon JA in Makita quoted above.

[18] Reliance is placed upon the fourth, sixth and seventh propositions stated in the passage quoted from the judgment of Heydon JA in Makita above.

[19] Heydon, Cross on Evidence, [29075].

[20] [1953] SC 34, 39-40.

[21] Sections 135 and 137 of the Evidence Act 2008 provide:

The court may refuse to admit evidence if its probative value is substantially outweighed by the danger that the evidence might -

137 Exclusion of prejudicial evidence in criminal proceedings

In a criminal proceeding, the court must refuse to admit evidence adduced by the prosecutor if its probative value is outweighed by the danger of unfair prejudice to the accused.

[22] Cf Dupas v The Queen [2012] VSCA 328, [63]-[241].

[23] 'Probative value' of evidence is defined by the Dictionary to the Evidence Act as meaning 'the extent to which the evidence could rationally affect the assessment of the probability of a fact in issue'.

[24] Pfennig v The Queen [1995] HCA 7; (1995) 182 CLR 461, 528 - 529.

[25] Cf Dupas v The Queen [2012] VSCA 328, [281]-[282].

[26] See R v BDX [2009] VSCA 28.

[27] Dupas v The Queen [2012] VSCA 328, [244].

[28] [2012] VSCA 321, [67].

[29] See also s 135 which applies to both criminal and civil trials and which confers a broad discretion to exclude evidence for reasons which include those specified in s 137.

[30] [2012] VSCA 328.

[32] Gary Edmond_,_ 'A Specialised Knowledge, The Exclusionary Discretions and Reliability', (2008) 31(1) UNSWLJ 11, 21.

[33] Makita (Aust) Pty Ltd v Sprowles [2001] NSWCA 305; (2001) 52 NSWLR 705, 729-30 (Heydon J).