Suppressed - [2021] WASCA 51

JURISDICTION     :   SUPREME COURT OF WESTERN AUSTRALIA
TITLE OF COURT :   THE COURT OF APPEAL (WA)
CITATION:   AKKERMAN -v- THE STATE OF WESTERN AUSTRALIA [2021] WASCA 51
CORAM:   MAZZA JA
VAUGHAN JA
HALL J

HEARD:   9 DECEMBER 2020
DELIVERED          :   23 MARCH 2021
FILE NO/S:   CACR 19 of 2020
BETWEEN:   SIMON MARIA RENE AKKERMAN
Appellant

AND

THE STATE OF WESTERN AUSTRALIA
Respondent

ON APPEAL FROM:
Jurisdiction              :   DISTRICT COURT OF WESTERN AUSTRALIA
Coram:   PRIOR DCJ
File Number            :   IND 2204 of 2018

Catchwords:

Criminal law - Appeal against conviction - Conviction after trial - Eight counts of unlawfully and indecently dealing with a child under the age of 14 years - Two complainants - Evidence at trial of a change in behaviour of one complainant at a time proximate to the offending - Whether trial judge erred in directing jury regarding change in behaviour evidence - Whether trial judge was required to give direction in accordance with type of direction upheld in MCA v The State of Western Australia [2019] WASCA 22

Legislation:

Criminal Code (WA), s 183

Result:

Leave to appeal granted
Appeal allowed
Convictions set aside
Retrial ordered

Category: B

Representation:

Counsel:

Appellant	:	T Percy QC & G Yin
Respondent	:	T B L Scutt

Solicitors:

Appellant	:	DG Price & Co
Respondent	:	Director of Public Prosecutions (WA)

Case(s) referred to in decision(s):

Azarian v The State of Western Australia [2007] WASCA 249; (2007) 178 A Crim R 19
Azzopardi v The Queen [2001] HCA 25; (2001) 205 CLR 50
Bull v The Queen [2000] HCA 24; (2000) 201 CLR 443
Carr v The Queen [1988] HCA 47; (1988) 165 CLR 314
Di Stefano v The State of Western Australia [2017] WASCA 187
Eades v The Queen [2001] WASCA 329
Grubisic v The State of Western Australia [2011] WASCA 147; (2011) 41 WAR 524
Hussain v The State of Western Australia [2020] WASCA 187
KSN v The State of Western Australia [2017] WASCA 156
Longman v The Queen [1989] HCA 60; (1989) 168 CLR 79
MCA v The State of Western Australia [2019] WACSA 22
MCA v The State of Western Australia [2019] WASCA 22
R v Flannery [1969] VR 586
RPS v The Queen [2000] HCA 3; (2000) 199 CLR 620
Suresh v The Queen [1998] HCA 23; (1998) 72 ALJR 769
Tully v The Queen [2006] HCA 56; (2006) 230 CLR 234
Vo v The State of Western Australia [2010] WASCA 24
Walsh v The State of Western Australia [2011] WASCA 119

MAZZA JA:

I agree with Hall J.

VAUGHAN JA:

Overview

This is an appeal against conviction.
The appellant was charged on indictment with eight counts. All concerned alleged contraventions of the former s 183 of the Criminal Code (WA) (Code)[1] by unlawfully and indecently dealing with a child under the age of 14 years. There were two complainants, JS and DB, who at the time of the alleged offences were school friends aged about 11. The offences were alleged to have occurred between 1 October 1989 and 1 January 1990 at a Perth suburb (counts 1 - 4) and on a separate occasion on an unknown date in 1989 at the same Perth suburb (counts 5 - 8). Counts 1 - 4 relied predominantly on the evidence of DB. Counts 5 - 8 relied predominantly on the evidence of JS.
[1] The relevant statutory provision was repealed with effect from 23 March 1990. However, as will be seen, it was the State case that each of the offences occurred in 1989.
On 25 October 2019, after a five day trial before Prior DCJ and a jury, the appellant was convicted on all counts.
The evidence at trial included evidence of JS's mother, LS, who, among other things, gave evidence of a change in behaviour on the part of JS over a period of time proximate to the alleged offending. The evidence was to the effect that JS's behaviour changed in 1989 after starting at a different local primary school, on moving to the Perth suburb in which the alleged offences occurred. Among other things JS began exhibiting sexualised behaviour. As a result of his behaviour, JS was taken to see psychologists and admitted to Princess Margaret Hospital.
The appellant relies on a single ground of appeal. The appellant alleges, in substance, that the trial judge erred in law by failing to give the jury an appropriate direction about the use that could be made of evidence about JS's change of behaviour proximate to the offending.

For the reasons that follow, although there should be leave to appeal, the appeal should be dismissed.

The State's case at trial

JS and DB were born in April 1978 and December 1977 respectively. JS and DB met in 1989 when JS commenced year 6 at a different local primary school after he and his family had moved house into the Perth suburb where the offences were alleged to have occurred. At that time - and at the time of the alleged offending - the two boys were around 11 years old. JS had moved to a house within walking distance of the local primary school. DB lived in the same area. The two boys often played in the bushland which surrounded the houses in the area.
JS gave evidence that:
1.He met the appellant - the appellant (then around 32 or 33 years of age)[2] lived in a house next to an undeveloped block on which JS and his friends played.[3] (The appellant's house was on a street at the back of the local primary school between JS's home and the primary school.)[4]
2.JS and the appellant first met in the middle to latter part of 1989.[5]
3.A friendship developed. JS and his friends, including DB, regularly visited the appellant's house.[6] This occurred after school and during school holidays.[7] JS and DB played an arcade game located in the appellant's home and drank Coke supplied by the appellant.[8] There were also pornographic magazines in the appellant's home that JS would pick up.[9]
4.The friendship with the appellant turned into a relationship with sexual activity - initiated by the appellant - in which DB was also involved.[10] It was no more than a couple of months before the friendship turned towards sexual activity.[11]
5.Sexual activity involving JS, DB and the appellant took place in the appellant's house.[12] There were also occasions where sexual activity took place between the appellant and JS outside of the appellant's home in the bushland surrounding the primary school[13] and in another location.[14]
[2] The appellant gave evidence that he was born in July 1956: ts 360.
[3] ts 63 - 66.
[4] ts 61 - 65.
[5] ts 110.
[6] ts 66.
[7] ts 69.
[8] ts 67 - 68, 71.
[9] ts 69.
[10] ts 70 - 71.
[11] ts 71.
[12] ts 71 - 75.
[13] ts 75.
[14] ts 76.
DB confirmed attending the local primary school, living in the general area and becoming friends with JS, having been in the same class with JS in years 6 and 7.[15] DB said that JS introduced him to the appellant - an older guy who lived near the school.[16] DB went to the appellant's home on more than 10 occasions.[17] DB normally went there with JS.[18] DB referred to engaging in various outdoor activities with the appellant but also said that, within his home, the appellant provided pornographic magazines and showed pornographic videos to JS and DB.[19] According to DB, the pornography led to self and mutual masturbation involving the appellant, JS and DB. This was towards the end of 1989, when DB was in year 6.[20] This then developed into the three of them performing mutual oral sex.[21] DB's evidence was that he and JS had engaged in sexual behaviour with the appellant at the appellant's house on numerous times.[22] However, DB was not able to say how many months after meeting the appellant it was before the first sexual activity occurred.[23]
[15] ts 184 - 188.
[16] ts 189.
[17] ts 191.
[18] ts 195.
[19] ts 195 - 196.
[20] ts 197.
[21] ts 197 - 198.
[22] ts 198. See also ts 200 - 202, 219.
[23] ts 210.
Counts 1 - 4 relied on DB's evidence. In substance they alleged indecent and unlawful dealings contrary to former s 183 of the Code on an unknown date between 1 October 1989 and 1 January 1990 by the appellant:
1.Permitting JS to perform fellatio on him (count 1).
2.Permitting DB to perform fellatio on him (count 2).
3.Permitting JS to masturbate him (count 3).
2.Permitting DB to masturbate him (count 4).
DB said that this occurred at about the end of year 6 or the beginning of year 7 (ie the end of 1989 or the start of 1990). The appellant was pretending to be asleep, naked, on the couch when JS and DB came into the house. JS and DB proceeded to masturbate him and performed oral sex. After that occurred the appellant masturbated himself to ejaculation.[24]
[24] ts 199 - 200, 219.
Counts 5 - 8 relied on JS's evidence. In substance they alleged indecent and unlawful dealings contrary to former s 183 of the Code on an unknown date in 1989 by the appellant:
1.Procuring JS to perform fellatio on DB (count 5).
2.Instructing DB to perform fellatio on JS (count 6).
3.Performing fellatio on DB (count 7).
4.Performing fellatio on JS (count 8).
JS gave evidence that these events occurred during the school holidays in 1989 in the appellant's bedroom. JS said that he met DB and they were at the appellant's house where they looked at pornography. When in the appellant's room the two boys and the appellant got undressed and were under the covers of the appellant's bed. JS was on one side of the appellant and DB was on the other. They fondled each other and, in JS's words, 'were giving each other blow jobs and kissing and hugging'. JS said that the appellant performed fellatio on JS and DB and, at the instigation of the appellant, JS performed fellatio on the appellant and DB, and DB performed fellatio on the appellant and JS. Among other things the appellant performed oral sex on the boys until he ejaculated. The parties were in the bedroom for half an hour.[25]
[25] ts 72 - 75.
JS also gave evidence about the appellant having moved house in 1990, and then moving on a second occasion, and JS continuing to meet with the appellant to engage in sexual activity.[26] JS said that he had a sexual relationship with the appellant for at least two years.[27] On JS's evidence, at some point in about 1991 or 1992, JS met a man in his 50s, K, who was living with the appellant in the third home of the appellant that JS frequented. JS was then in year 8 or year 9 and about 12 or 13 years old. JS then formed a sexual relationship with K at K's instigation.[28]
[26] ts 79 - 81, 83, 88 - 89.
[27] ts 90.
[28] ts 91 - 92. See also ts 140 - 141.
Relevantly to the appeal, JS gave evidence that the offending brought about certain behavioural changes on his part. The following evidence was led in examination-in-chief:
[JS], did what was going on between you and [the appellant] influence the way you behaved with any of your friends?---Yes, it did.
Can you state how?---I was acting in an overtly sexual way towards some of my friends.[29]
[29] ts 81.
In subsequent evidence JS clarified that this concerned a single occasion in which he and DB engaged in sexual activity at DB's home.[30]
[30] ts 81 - 82.
More generally, JS gave evidence that during this part of his childhood his behaviour towards his parents became more erratic. He lied and cut himself. JS described himself as being irrational, having nightmares and stealing things. He was not interested in school anymore. At some point he saw numerous psychologists and was admitted as a patient in Princess Margaret Hospital.[31]
[31] ts 93 - 94, 142.
JS's evidence was that he did not inform the medical personnel of the sexual activities with the appellant or K because he would get into trouble and he did not want to get into trouble.[32]
[32] ts 94.
In addition to the two complainants' evidence, the State's case comprised of evidence from JS's mother, LS, and two investigating police officers. The evidence of LS is considered at [24] - [31] below.

The appellant's case at trial

The defence case consisted of two witnesses: the appellant and his sister. In substance the appellant denied the offending.[33] His case was that the offending did not happen.[34] The appellant admitted having met JS while living at the property opposite the back of the local primary school.[35] The appellant lived at that property from September 1988 to mid-August 1990, when he moved into another house in the same suburb.[36] The appellant moved to a third property, also in the same suburb, in mid-February 1991.[37] However, the appellant denied ever even knowing DB.[38]
[33] ts 403 - 404, 412, 419, 425.
[34] ts 28 (extract 24/10/19).
[35] ts 56, 388.
[36] ts 56, 365, 400.
[37] ts 56, 400.
[38] ts 389, 403, 420 - 423, 425.
In support of the defence case that the alleged offending never happened, and in addition to contending that the appellant should be accepted as a truthful witness, counsel for the defence focussed on:[39]
1.Inconsistencies in the complainants' evidence (including whether the jury could be satisfied beyond reasonable doubt that the alleged offences occurred before 23 March 1990) and their credibility and reliability more generally.
2.The vagueness in the complainants' evidence.
3.The delay in a complaint (in the case of JS) and the lack of any complaint (in the case of DB).
4.The forensic disadvantage the appellant was at in establishing his defence because of the 30 years that had passed since the alleged offending.
5.Deficiencies in the police investigation of the alleged offending.
[39] ts 28 - 48 (extract 24/10/19).
Among other things, counsel for the defence suggested that the jury may conclude that any sexual abuse of JS was by K rather than the appellant.[40]
[40] ts 38, 40, 48 (extract 24/10/19).

The evidence of LS

LS is JS's adopted mother. LS and her husband had two biological children who were born in 1971 and 1977. JS came to live with LS and her husband as a foster child in 1981 when he was 3 years old. According to LS, it was not until JS was 12 or 13 years old that JS was formally adopted.[41] LS and her husband adopted a further two children, who were born in 1981 and 1984 respectively. LS confirmed that until January 1989 the family lived in a particular northern suburb of Perth. JS attended the local primary school. In January 1989 the family moved to an adjacent northern suburb of Perth. JS moved to a new primary school in that suburb for years 6 and 7 in 1989 and 1990. Subsequently JS attended a local high school from year 8 until year 10.[42]
[41] JS's evidence was that he was officially adopted in 1987 when he was 9 years old: ts 60.
[42] JS's evidence was that he continued at the high school until year 11: ts 94.
LS described JS as 'very adventurous' and a 'friendly, outgoing little boy' without problems when he came to live with LS and her husband.[43] He remained a normal, outgoing and friendly child while being raised in the first suburb.[44] However, JS's behaviour changed after the family moved and he started at the second primary school; there were things happening with JS's behaviour that were 'unusual'.[45] LS referred to JS having terrible nightmares, drawing disturbing pictures (the example given being pictures of monsters with knives, chains and dripping blood) and chopping the feet and hands off his sister's Barbie dolls.[46] In cross-examination LS also referred to JS being in trouble for stealing at school in September 1989.[47]
[43] ts 165.
[44] ts 166.
[45] ts 166. See also ts 174.
[46] ts 166 - 167.
[47] ts 174.
As JS was still being fostered, LS sought assistance from the child welfare authorities. JS was taken to see psychologists and was admitted to Princess Margaret Hospital on one occasion for two weeks.[48] LS referred to being informed that JS's birth mother suffered from schizophrenia and having paranoid delusions. JS was admitted for assessment to see if he suffered from similar conditions.[49] LS said she was told that JS was not suffering from schizophrenia.[50]
[48] ts 167.
[49] ts 174.
[50] ts 175.
There was no evidence as to the dates of JS's hospitalisation or when he attended for psychological evaluation. However, as mentioned, JS - albeit in response to a leading question from the prosecutor - said that he did not tell the staff at Princess Margaret Hospital about the kind of life he was leading with the appellant and K.[51] That would place JS's hospitalisation as having occurred in 1991 at the earliest, given the evidence as to when JS first met K (see [15] above). This can be further refined to after mid-February 1991 given JS's evidence that he met K at the appellant's third residence and the appellant's evidence that he moved into the third home in mid-February 1991 (see [15] and [21] above).
[51] ts 94.
On appeal the State suggested that in the chronological context of the examination of JS and LS it could be inferred that JS's hospitalisation occurred at the end of primary school (ie 1990).[52] I do not agree that this may be inferred from the evidence.[53] JS's response to the prosecutor's questioning is inconsistent with the drawing of such an inference and places JS's hospitalisation as being in 1991 at the earliest. At the very least the debate demonstrates the vagueness of much of the behavioural change evidence - a vagueness correctly acknowledged by counsel for the State who stated that there was a 'lot of ambiguity' as to the timing of the change in behaviour.[54]
[52] Respondent's submissions par 11 WAB 18; Appeal ts 21 - 22.
[53] See ts 94, 167, 174 - 175.
[54] Appeal ts 21.
In addition to the general evidence of behavioural change after starting at the different primary school, the following evidence of LS was led in examination-in-chief:
Did you ever observe any, and I don't mean in private, any sexualised behaviour on the part of [JS]?---Yes, we - we did.
Where - where was that? And again, I don't mean in his bedroom?---He - it was in the lounge room while the - the children - the - two of the other children were in there watching television with him and it was in the back of the car when we were going out, going shopping, going to church.
And what kind of behaviour did you see in those places?---He - he was masturbating.[55]
[55] ts 167.
Again, there was no examination or clarification as to when these incidents occurred. They could have occurred at any time from 1989 onwards until JS left the family home when he was 15 or 16 (which must have been in around 1993 or 1994). JS himself denied that these particular incidents occurred but accepted that he was out of control.[56]
[56] ts 142.
LS went on to give evidence that JS moved out of the family home when he was 15 years old.[57] This followed an incident in which it had been reported to LS and her husband that JS had been in the bed of his younger sister and had hurt her. LS never investigated what had happened. LS simply said that JS needed extra help that they could not give. JS moved to a hostel for a few months and later moved in with K.[58]
[57] However, JS's evidence was that he left the family home when 16 and in year 11 at high school: ts 94, 141.
[58] ts 168 - 169, 173.
This incident (at a time when JS was 15 or 16 years of age) plainly occurred well after the alleged events the subject of the indictment (at a time when JS was about 11 years of age). It also occurred after the sexual abuse of JS as instigated by K.

The parties' closing addresses to the jury and the trial judge's summing up

In his closing address the prosecutor referred to LS's evidence when addressing JS's delay in making a complaint. The prosecutor said:
The evidence of his mother [LS] is very significant here. The boy she and her husband … fostered and then adopted had been a friendly, cheerful child when they lived in [suburb 1] but when they moved to [suburb 2] it all changed. He got these awful nightmares about monsters. He said the monster was in his school I think [counsel for the defence] got [LS] to say. Well, the monster lived near the school.
He [ie JS] started misbehaving. He started stealing. He started overtly engaging in sexual behaviour. He started masturbating in the presence of his brothers and sisters in the lounge room, in the car …
Now, I'm not asking you to conclude that the deterioration in [JS's] mental state, his behaviour and his relations with his family deteriorated because of the sexual abuse. I can't prove that these things are causally linked. What I can say to you, though, is this. Given what you've heard about the behavioural problems he was having at home at [suburb 2] that weren't there at [suburb 1], are you surprised to find that he says he was sexually abused at [suburb 2]?
Does it shock you that a boy with behavioural problems turns out to be saying, credibly and with corroboration from another child, that he was being sexually abused at the time? I don't think it should surprise you. I think it's what you'd expect.[59] (emphasis added)
[59] ts 22 - 23 (extract 24/10/19).

Counsel for the defence referred to LS as an impressive witness and suggested that the jury would have little difficulty in accepting her evidence.[60] Counsel for the defence also noted LS's evidence about JS's behavioural issues but said nothing further about the evidence than to highlight that JS told LS that the monster in his nightmares was standing at the desk at school, not opposite the school.[61]
[60] ts 40 (extract 24/10/19).
[61] ts 40 (extract 24/10/19).
Before the trial judge charged the jury, his Honour invited counsel to address him on possible directions. The prosecutor re-visited that invitation after counsel for the defence addressed the jury. The prosecutor referred to LS's behavioural evidence and raised whether it might necessitate a 'circumstantial evidence direction' whereby the jury were cautioned that they could not automatically reach any deduction about what led to the behaviour.[62] The trial judge expressed some reticence about giving a circumstantial evidence direction as it was a 'pretty black-and-white case' but said that he would think about it overnight.[63]
[62] ts 461.
[63] ts 461 - 462.
After the discussion with the prosecutor, the following exchange occurred between the trial judge and counsel for the defendant:
[Trial Judge]: What do you think about that …?
[Defence counsel]: Your Honour, I think they do need to get some sort of warning that they can't use it to reason that he was abused because ‑ ‑ ‑
[Trial Judge]: Okay.
[Defence counsel]: - - - there is no evidence to draw that link, but I wouldn't say a circumstantial direction is required.
[Trial Judge]: All right.[64]
[64] ts 462.
In charging the jury the trial judge did not re-visit LS's evidence at length. His Honour referred to how LS gave evidence about JS becoming a part of the family[65] and the statement by counsel for the defence that the jury could find LS to be a credible witness.[66] The trial judge did, however, refer to the prosecutor's use of JS's evidence of his behavioural change in the context of the delayed complaint. His Honour summarised the prosecutor's statement about:
[JS's] own evidence about his behaviour changing as a child. He misbehaved when he was living in [suburb 2] so effectively he was going through a troubled period in his life so that may to some extent explain why they didn't complain or there's a delay in the complaint.[67] (emphasis added)
[65] ts 492.
[66] ts 504.
[67] ts 502.
In addressing the jury, the trial judge also said:
Now, you heard both [JS] and [LS] give evidence about his [ie JS's] change in behaviour when they were living in [suburb 2], so the change in [JS's] behaviour as a child, and then eventually he went to a hostel when he was 15.
Be careful when you're considering that evidence. Don't speculate about this. The only evidence you have about what may have caused his behavioural change is [JS] himself. Concentrate on his evidence about what his interaction was with [the appellant]. Are we satisfied beyond reasonable doubt the acts of sexual abuse occurred between [JS] and [the appellant]?[68] (emphasis added)
[68] ts 512.
Before turning to the ground of appeal, something more should be said about the trial judge's summing up.
His Honour gave orthodox directions about the role of the jury and the standard and burden of proof.[69] The trial judge emphasised, twice, that before the appellant could be convicted of any counts on the indictment the jury needed to be satisfied beyond reasonable doubt as to the truth and reliability of JS's and DB's evidence in relation to that matter.[70] If the jury accepted the appellant's evidence, or thought it might be true or had given rise to a reasonable doubt on that issue, the jury could not convict.[71] If the jury rejected the appellant's evidence, it should be put to one side: the jury had to consider whether, on the basis of the evidence that was accepted as proven, the State had proven the guilt of the appellant beyond reasonable doubt.[72]
[69] ts 474 - 475, 479 - 480, 483 - 486, 506, 510.
[70] ts 476, 513. See also ts 508.
[71] ts 480.
[72] ts 480 - 481.
In addition, as will be seen, the trial judge gave a comprehensive Longman warning.[73] Among other things, the trial judge stated that there was no corroboration or confirmation of JS's and DB's evidence and no other evidence that the events happened (excluding the confirmation that each of JS and DB provided for the other's evidence).[74]
[73] See Longman v The Queen [1989] HCA 60; (1989) 168 CLR 79.
[74] ts 513.
Neither the prosecutor nor counsel for the defence sought any redirection or additional direction from the trial judge.[75] The point taken on appeal - and the further point which only emerged in the course of the appeal hearing in discussion between the court and counsel for the State - was never taken by the appellant's experienced and competent trial counsel who was absorbed in the atmosphere of the trial and who was well cognisant of the behavioural change evidence and the sort of direction it might necessitate.
[75] ts 517 - 518.

The ground of appeal and the parties' contentions

The single ground of appeal reads:
The learned trial Judge erred in law by failing to give the jury an appropriate direction about the use they could make of the evidence about the complainant JS's change of behaviour proximate to the offending.
The appellant submitted that the change of behaviour evidence was highly prejudicial. It was contended that, without direction, there was a real risk that the jury might have reasoned that the evidence confirmed JS's allegations.[76] The appellant submitted that the direction given gave no guidance as to how the jury might use the change in behaviour evidence.[77] The appellant said that the trial judge was required to give the jury a direction about the evidence in accordance with the type of direction upheld in MCA v The State of Western Australia.[78] This was because, in the appellant's submission, the jury may well have reasoned that the change in behaviour evidence could lead to a conclusion that the change in JS's behaviour was caused by the appellant's sexual conduct towards JS.[79] The appellant contended that the change in behaviour evidence could be admissible to prove conduct on the part of JS consistent with being abused by the appellant. It followed that the trial judge was required to give a direction about how the evidence could be used and the path the jury had to follow before it could be used in that way.[80]
[76] Appellant's submissions par 12 WAB 8.
[77] Appellant's submissions par 14 WAB 9.
[78] MCA v The State of Western Australia [2019] WASCA 22; see appellant's submissions par 14 WAB 9.
[79] Appellant's submissions par 19 WAB 9 - 10.
[80] Appellant's submissions par 24 WAB 10.
According to the appellant, the necessary direction was that the jury could only use the evidence about JS's change in behaviour if the only reasonable inference was that it occurred as a result of the appellant's offending.[81] Senior counsel for the appellant contended that, the prosecutor having relied on the change of behaviour evidence in his address to the jury, there should have been a direction in the form of the direction that this court upheld in MCA.[82]
[81] Appellant's submissions par 22 WAB 10.
[82] Appeal ts 9, 11 - 12.
The appellant submitted that such a direction was of particular importance in the circumstances of the present case because JS was sexually abused by K. Some of the behavioural changes occurred after JS had commenced a sexual relationship with K.[83] The State accepted that some but not all of the change in behaviour evidence related to a period in which JS was being sexually abused by K.[84] While accepting that there were ambiguities in the evidence as to the dates, the State said that it was clear from the evidence that some of the behavioural changes occurred in 1989 or 1990 and thus before the earliest date of any sexual abuse on the part of K.[85]
[83] Appellant's submissions par 23 WAB 10.
[84] Respondent's submissions pars 3, 5 - 13 WAB 15 - 18.
[85] Respondent's submissions pars 7, 9 WAB 17.
The State contended, however, that the direction given by the trial judge was not erroneous and was favourable to the appellant.[86] The State submitted that:
1.The prosecutor expressly eschewed inviting the jury to find a causal link between the appellant's alleged offending and JS's change in behaviour. It was acknowledged, however, that the prosecutor's additional remarks made immediately thereafter suggested that the change in behaviour was conduct consistent with the alleged offending, thus apparently relying on the evidence so as to buttress JS's credibility.[87]
2.The change in behaviour evidence was a double edged sword for the prosecution as it might impact adversely on JS's credibility and reliability - something that defence counsel made use of.[88]
3.The direction now said to be required was, in substance, that which counsel for the defence had said was unnecessary - in discussion with the trial judge it was said that a circumstantial evidence warning was not required.[89]
4.In summarising the State and defence cases for the jury, the trial judge placed the prosecutor's reliance on the change of behaviour evidence in the context of JS's delay in making a complaint.[90]
[86] Respondent's submissions par 3 WAB 15.
[87] Respondent's submissions par 14 WAB 19; Appeal ts 18, 25.
[88] Respondent's submissions par 15 WAB 19 - 20.
[89] Respondent's submissions pars 17, 27 WAB 20, 23.
[90] Respondent's submissions par 21 WAB 21.
The State also made reference to the direction reproduced at [38] above and a Longman warning that followed in which, among other things, the trial judge stated:
They [ie JS and DB] of course are the only witnesses against [the appellant] as to the happening of the events alleged in the indictment. Whilst there's been other evidence, no one has confirmed or corroborated [JS's] or [DB's] evidence as to the offences themselves. Of course, they confirm each other's evidence as to this, but there's no other witnesses who were there at the time …[91] (emphasis added)
… you should scrutinise both their evidence with special care. You should take carefully into account that these events are alleged to have happened some 30 years ago. They're allegations of serious sexual crimes. No complaint was made around the time. There's no corroboration or confirmation of the evidence of [JS] and [DB] and there's no other evidence that the events happened. Of course, the exception is both [JS] and [DB] gave evidence that they were both present together when [the appellant] committed the eight alleged offences, so they corroborate each other.[92] (emphasis added)
… it would be dangerous to convict [the appellant] on the uncorroborated evidence of [JS] and [DB] unless, having scrutinised their evidence with great care, having considered the circumstances relevant to that evidence and to which I've referred to and taking full account of the warning I've just given to you, you're satisfied beyond reasonable doubt as to the truth and accuracy of that evidence.[93] (emphasis added)
[91] ts 512 - 513.
[92] ts 513.
[93] ts 516.
The State challenged the appellant's reliance on MCA. The State contended that MCA did not establish that a warning, as given in that case, must be given in every case where there is evidence of a contemporaneous change in behaviour by a complainant in an alleged sexual offence.[94] The State argued that in MCA the court reasoned by analogy with regard to the principle that distress may corroborate the evidence of a complainant and said that it was a question for the trial judge whether the evidence was capable of being used in that way.[95] According to the State, the trial judge evidently decided that the evidence could not be used as being corroborative of JS's evidence of the offending and directed accordingly.[96] That was said to be favourable to the appellant - as were the directions reproduced at [48] above - whereas any direction of the kind now contended for by ground 1 would have invited speculation and placed more emphasis on the evidence than was warranted.[97]
[94] Respondent's submissions par 30 WAB 24.
[95] Respondent's submissions pars 31 - 34, 36 WAB 24 - 26.
[96] Respondent's submissions pars 36, 42 WAB 26, 28.
[97] Respondent's submissions pars 36 - 39, 42 WAB 26 - 28.

Disposition

In order to ensure a fair trial, a trial judge may be required to direct a jury as to how evidence may be used in reaching a verdict, including how the evidence may not be used. So too the trial judge must give the jury such warnings against following impermissible paths of reasoning as may be called for by the particular case.[98] As was said by the plurality in RPS v The Queen, in making more general observations about the difficult task that a trial judge has in giving a jury proper instructions:
In some cases it will require the judge to warn the jury about how they should not reason or about particular care that must be shown before accepting certain kinds of evidence.[99] (original emphasis)
[98] Azzopardi v The Queen [2001] HCA 25; (2001) 205 CLR 50 [49].
[99] RPS v The Queen [2000] HCA 3; (2000) 199 CLR 620 [41].
Sometimes it may be necessary to specifically warn the jury that the evidence cannot be used as proof of a particular fact or issue or to reason in a particular way.[100] This is not every case: appropriate warnings or directions ought to be fashioned and provided to meet the demands of the individual case rather than being delivered mechanically or by rote when inapposite. A trial judge's charge to the jury must be clear, concise and complete but avoid the superfluous which may only confuse. However, as an incident of the trial judge's duty to ensure a fair trial for the accused, a trial judge is bound to give a direction or a warning to the jury if, in the circumstances of the particular case, the direction or the warning is necessary to avoid a perceptible risk of a miscarriage of justice.[101]
[100] Bull v The Queen [2000] HCA 24; (2000) 201 CLR 443 [69].
[101] Hussain v The State of Western Australia [2020] WASCA 187 [70] (referring to: Carr v The Queen [1988] HCA 47; (1988) 165 CLR 314, 324 ‑ 325; Longman v The Queen (86); RPS v The Queen [41]; Tully v The Queen [2006] HCA 56; (2006) 230 CLR 234 [123], [158]).
The appellant relied heavily on MCA. MCA concerned an appeal against conviction for sexual offending against two female complainants under the age of 13 years. Evidence of a change in behaviour of one complainant proximate to the offending was admitted despite objection.
There were two main issues in the appeal. First, whether the trial judge erred in admitting the change in behaviour evidence. That was resolved against the appellant. This court was satisfied that the evidence was significantly probative in two respects: (1) it might explain why the relevant complainant did not complain to her mother;[102] and (2) it might be accepted as behaviour consistent with the complainant being sexually abused as she alleged - thus supporting and corroborating the complainant's testimony as to the alleged sexual behaviour towards her (at least where the jury was satisfied that it was the only reasonable explanation for the behaviour).[103] The second issue was whether the trial judge adequately directed the jury regarding the change in behaviour evidence. It is this second aspect of MCA which is raised on this appeal.
[102] MCA [48], [50].
[103] MCA [48], [50], [57] - [60], [63].
In MCA the appellant contended that the trial judge should have directed that the change in behaviour evidence was admitted for a limited purpose only - to confirm what the complaint had said about her relationship with her mother and why the complainant had not complained to her.[104]
[104] MCA [53]. See also [34] which reproduces the relevant ground (ground 2) as advanced in MCA.
The trial judge did not give any such direction. It may be observed that such a direction would have been inconsistent with the second basis on which this court found that the evidence was admissible. However, the trial judge did direct the jury as to how facts might be proved by inference. In the course of doing so the trial judge referred to the State's case that the jury might draw the inference that the change in behaviour was consistent with the complainant being sexually dealt with as the complainant alleged. The trial judge directed the jury, in effect, that it would not be proper to draw any such adverse inference unless they reached the conclusion that it was the only reasonable inference open on all the evidence; and, moreover, drew the jury's attention to the possible alternative reasons for the complainant's apparent change in behaviour.
This court upheld the trial judge's directions in relation to the change of behaviour evidence as being sufficient in the circumstances of the particular case, noting that it was similar in form to directions customarily given as to evidence of the distressed condition of a complainant.[105]
[105] MCA [64] - [65].
Two things should be said about MCA at this point. First, unlike the present case, in MCA the prosecutor relied on the evidence of change in behaviour proximate to the alleged sexual offence as being corroborative of the fact of the alleged offending. Second, MCA does not establish that a direction of the kind given by the trial judge in that case must be given whenever there is change of behaviour evidence; it simply establishes that the direction given in MCA was adequate in the particular circumstances of that case.
Accordingly, while MCA is of assistance in considering the issue presented in this appeal, it is far from being determinative of the appeal.
At the appeal hearing, counsel for the State observed, correctly, that MCA identified three possible uses for evidence of behavioural change in a complainant at a time proximate to alleged sexual offending:[106]
1.It may explain why there was no complaint at the time - specifically it may explain why a child complainant made no complaint to one or both of his or her parents.
2.It may demonstrate 'consistency of behaviour'[107] - meaning it may be taken into account as possibly enhancing the credibility of the complainant's testimony rather than constituting separate and independent evidence that corroborates the complainant's evidence of the sexual offending itself.
3.It may corroborate the evidence of the complainant as to the alleged sexual offending (at least where the jury is satisfied that it is the only reasonable explanation for the behaviour).
[106] Appeal ts 16.
[107] MCA [59].
As mentioned, the State submitted that in MCA this court reasoned by analogy from the principles applying to evidence of the distressed condition of a complainant. The State then sought to develop the analogy with the authorities concerning distress.[108]
[108] Respondent's submissions pars 31 - 41 WAB 24 - 28.
The State is correct to observe that in MCA the court referred to the permissible use of evidence of the distressed state of a complainant and then proceeded to apply analogous reasoning to evidence of behavioural change proximate to the alleged sexual offending.[109] It is, however, necessary to recognise that the analogy is imperfect. For example, evidence of distress is likely to be more closely linked with evidence of complaint. By contrast, change in behaviour may precede complaint or be present without any complaint; it may be sudden or gradual. Moreover, depending on its nature and the circumstances of the case, evidence of change in behaviour: (1) may be more imprecise and difficult to accurately describe than evidence of a distressed state (often because it will be difficult to identify change in behaviour without some hindsight bias); (2) may be thought to be more susceptible to being related to one or more alternate causes (particularly so where the evidence of behavioural change extends progressively over a lengthy time period); but (3) may be thought to be less susceptible to being feigned than distress (the rationale that distress may be feigned being one of the reasons often suggested in support of a contention that a trial judge provide a warning as to the weight to be given to any evidence of distressed condition).
[109] MCA [59].

The following propositions arise from the authorities as to evidence of complaint and distressed condition:
1.Evidence of recent complaint of sexual assault is only admissible as showing consistency of conduct - it is relevant to the credibility of the complainant and cannot be relied on to prove the truth of the alleged sexual assault. Such complaint evidence is admissible solely for the purpose of buttressing the credibility of the complainant.[110]
2.Evidence of the distressed condition of a complainant at the time a complaint was made may also be relevant to the credibility of the complainant - it relates to the manner in which the complaint was made and may show consistency. Accordingly, evidence of a state of distress may be used as being supportive of the complainant's credibility.[111]
3.In addition, and unlike evidence of recent complaint, evidence of the distressed condition of a complainant who claims to have been sexually assaulted may corroborate the evidence of the complainant in relation to the allegation of sexual assault - it is sometimes evidence that may be used to support a conclusion that an assault in fact occurred.[112]
4.The complainant's distressed condition must implicate the accused if it is to have the effect of constituting corroboration. It must be reasonably explicable only on the basis of the alleged sexual assault having occurred.[113]
5.It is a question for the trial judge whether the evidence is capable of being used in that way.[114]
6.Evidence of distressed condition is not capable of amounting to corroboration where it is not open to draw an inference that there was a causal connection between the distressed condition and the alleged sexual assault.[115]
7.A warning as to the weight to be attributed to evidence of distressed condition as being corroborative of an alleged sexual assault may be required but is not required in every case. Whether such a warning is required depends on the particular circumstances of the case.[116]
8.This court has left open whether it is necessary to direct a jury that, when evidence of distressed condition is used solely to buttress credibility and is not relied on as corroboration, the evidence should only be treated as supporting a complainant's credibility if there is no other reasonable explanation for the behaviour consistent with the accused's innocence.[117]
[110] Suresh v The Queen [1998] HCA 23; (1998) 72 ALJR 769 [4] - [6]; KSN v The State of Western Australia [2017] WASCA 156 [39] ‑ [40].
[111] Grubisic v The State of Western Australia [2011] WASCA 147; (2011) 41 WAR 524 [107]; Di Stefano v The State of Western Australia [2017] WASCA 187 [20].
[112] R v Flannery [1969] VR 586, 591; Eades v The Queen [2001] WASCA 329 [32]; Azarian v The State of Western Australia [2007] WASCA 249; (2007) 178 A Crim R 19 [44] ‑ [46], [155]; Vo v The State of Western Australia [2010] WASCA 24 [36]; Grubisic v The State of Western Australia [70], [72], [107]; Di Stefano v The State of Western Australia [20] - [21]; MCA [59].
[113] Grubisic v The State of Western Australia [70]; Di Stefano v The State of Western Australia [21].
[114] Eades v The Queen [32]; Azarian v The State of Western Australia [155]; Grubisic v The State of Western Australia [72].
[115] R v Flannery (591); Eades v The Queen [32]; Azarian v The State of Western Australia [155].
[116] Eades v The Queen [33] - [34], [37]; Azarian v The State of Western Australia [47] - [48], [157]; Vo v The State of Western Australia [37] - [40]; Grubisic v The State of Western Australia [71] - [72], [108] ‑ [112], [126]; Di Stefano v The State of Western Australia [25].
[117] Walsh v The State of Western Australia [2011] WASCA 119 [68]; Di Stefano v The State of Western Australia [23].
It is not necessary to consider the precise extent to which these principles apply by analogy where there is evidence of change in behaviour proximate to the time of alleged sexual offending. The parties did not make submissions on that question. It is sufficient for this appeal to accept that the principles as to evidence of distressed condition will provide broad guidance when considering questions concerning behavioural change evidence.
In the present case the behavioural change evidence was not relied on as being corroborative of the fact of the alleged sexual offending. In addressing the jury the prosecutor expressly disavowed any case of causal connection. The trial judge was careful to exclude any possibility of the jury reasoning that the evidence of behavioural change could support a conclusion that the sexual offences the subject of JS's evidence in fact occurred. His Honour directed in plain and clear terms that, apart from JS and DB confirming each other's evidence, there was no corroboration or evidence of the fact of the alleged sexual offending. To emphasise the lack of any evidence of corroboration the trial judge made the point on three separate occasions.
In so doing the trial judge apparently considered that the evidence of behavioural change was not capable of being corroborative of the fact of the alleged sexual offending. His Honour was correct to so conclude. In any event, on the appeal no party contended that the evidence of behavioural change was such that it was open to infer - as the only reasonable explanation for the behaviour - that JS's change in behaviour was caused by the appellant's sexual conduct towards him.
In the circumstances there was no perceptible risk that the jury might reason that the evidence of behavioural change confirmed JS's allegations. That was not the State's case. It was reasoning that would be inconsistent with the trial judge's plain and clear direction that there was no corroboration or evidence of the fact of the alleged sexual offending apart from JS's and DB's own evidence. There was no basis to suggest, and it was not suggested, that this was an occasion where the jury would not faithfully apply the trial judge's direction. A direction of the kind contended for on appeal - that the evidence could only be used if the only reasonable inference was that it occurred as a result of the appellant's offending - was not required and might potentially confuse the jury. It would be tantamount to a direction as to how the jury may reason towards a verdict of guilty, relying on the evidence of change in behaviour as proof of the fact of the alleged sexual offending, even though the prosecutor had eschewed such reasoning and the trial judge had evidently concluded that the evidence was not capable of being used in that way. The trial judge's plain and clear direction closed out the risk of any such erroneous reasoning on the part of the jury as was contended for on appeal and did so without potentially confusing the jury as to the use to which the evidence may be put.
So understood, it is unsurprising that counsel for the defence did not, at the conclusion of the trial judge's charge to the jury, press for 'some sort of warning' as had earlier been counsel's position. Counsel recognised, correctly, that the trial judge had dealt with the issue favourably to the appellant. The trial judge had negated the risk of the jury misusing the behavioural change evidence as being evidence amounting to corroboration without over-complicating the issue or highlighting the evidence to the potential disadvantage of the appellant.
This is sufficient to resolve, negatively, the appellant's primary contention on the appeal. However, at the appeal hearing senior counsel for the appellant embraced an alternative concern expressed by the court when hearing from counsel for the State: whether the trial judge's direction adequately addressed the prosecutor's implicit suggestion that the evidence of behavioural change was consistent conduct that buttressed JS's credibility (see [33] and [47.1] above). In oral reply submissions senior counsel for the appellant submitted that in those circumstances an MCA type direction should have been provided even if the behavioural change evidence was only being used in relation to credit as consistency evidence - particularly so given that the central issue at trial was the dispute between the complainants' and the appellant's evidence and JS's credibility was critical to that contest.[118]
[118] Appeal ts 26, 29 - 31.
In my opinion, an MCA type direction would have been ill-suited to address the concern arising from the prosecutor's additional observations.
The concern with the prosecutor's additional observations is threefold:
1.First, the case for consistency between some of the conduct pointed to by way of evidence of a change in behaviour and the alleged sexual offending was tenuous at best (eg the conduct consisting of drawing disturbing pictures and stealing at school).
2.Second, the prosecutor referred to JS's behavioural issues without discrimination as if all the behaviour could be bundled together. That was misconceived. As I have endeavoured to explain, while some of the change in behaviour was close to the time of the alleged offending, other such evidence was of events that post-dated the alleged offending by a number of years, and some of the behavioural change evidence did not permit any conclusion to be drawn as to the date of the conduct. That might have been of less significance so far as the evidence was to explain the lack of any complaint. But the temporal discrepancies and lack of precision affected the weight of the evidence so far as it was suggested to show consistency of conduct.
3.Third, the prosecutor made no mention that - from sometime in 1991 on JS's evidence - any change in behaviour was explicable in terms of the sexual abuse JS had suffered at the hand of K. It would have been plain to the jury, however, that there was no contest that JS had been sexually abused by K. Counsel for the defence said as much,[119] pointing to K as the actual offender rather than the appellant.[120] The trial judge also referred to JS's evidence of being sexually abused by K and repeated what was said by counsel for the defence.[121]
[119] ts 29, 48 (extract 24/10/19).
[120] ts 38, 40 (extract 24/10/19).
[121] ts 488 - 489, 504, 511 - 512.
The trial judge did not pick up or expressly refer to this additional aspect of the prosecutor's address. There was no direction that the jury could use the evidence not as corroboration but to find consistency in the conduct of the complainant - or, conversely, to warn or direct the jury that the evidence should not be used in this way at all. Nor did his Honour refer to the possible lack of connection and temporal equivocation of parts of the change in behaviour evidence. Similarly, there was no mention of the question of weight that arose as to events that occurred well after the time of the alleged offending - events that might, in some respects, be explained by the sexual abuse inflicted by K.
Rather, as reproduced at [38] above, the trial judge suggested that the jury should be careful about considering the change in behaviour evidence. The jury were directed not to speculate about that evidence. Importantly, in a context where the jury had been directed that it needed to be satisfied beyond reasonable doubt as to the truth and reliability of JS's evidence, the trial judge directed the jury that the only evidence about what may have caused the behavioural change was from JS himself. In that context the trial judge directed the jury to '[c]oncentrate on [JS's] evidence about what his interaction was with' the appellant and whether they were satisfied beyond reasonable doubt that acts of sexual abuse occurred between the appellant and JS.
In that latter respect, there is no complaint about the trial judge's more general directions in relation to the assessment of a witness's credibility and reliability, the evidence as a whole and the parties' respective cases on the evidence. The trial judge's directions in this regard were appropriate and adequate in the circumstances. As articulated on appeal, issue is only taken as to the absence of a MCA type direction in relation to JS's and LS's evidence of change in behaviour proximate to the alleged offending.
The trial judge's directions did not suggest that the evidence of change in behaviour could be taken into account in assessing JS's credibility. This was, as the State suggested on the appeal, perhaps unduly favourable to the appellant. At least part of the behavioural change evidence was available to buttress JS's credibility as demonstrating consistency in conduct. However, had the trial judge so directed - with the change in behaviour evidence then assuming a greater significance within the trial judge's directions - his Honour might well have considered it necessary to address the additional matters I have referred to at [70] above.
The trial judge did not take this course. Instead, effectively confining the use of the behavioural change evidence to potentially explaining the lack of any contemporary complaint, his Honour directed the jury to concentrate on JS's evidence as to the alleged sexual offending. The trial judge did so having already provided the direction that there was no corroboration of the evidence as to the offences other than JS's and DB's own evidence. In substance, the trial judge invited caution as to any consideration of JS's and LS's evidence of change in behaviour and suggested that the jury instead focus on the central issue of whether the sexual offending itself occurred. So far as, in this way, the jury would consider and determine JS's credibility independently before determining whether any significance attached to the evidence of change in behaviour, the latter inquiry ceased to have any real consequence: the initial inquiry determined the case. The direction as made eliminated any perceptible risk that the jury may use the behavioural changes as being supportive of JS's credibility.
In the circumstances I am not persuaded that the trial judge was required to provide the jury with a direction of the kind provided in MCA (that being the appellant's contention on the appeal).
I have already explained why an MCA type direction was not required to address any use of the change in behaviour evidence as implicating the appellant by being corroborative of the fact of the alleged sexual offending. The trial judge's directions, in substance, took that away from the jury as a permissible line of reasoning: his Honour directed that there was no corroboration or evidence that the events happened other than JS's and DB's own evidence. Nor, in my view, was there any requirement for a modified MCA type direction - one tailored to use of the evidence as demonstrating consistency of conduct so as to buttress JS's credibility.
The prosecutor's additional observations were not, in terms, expressed in the language of consistency or buttressing JS's credibility. Had the trial judge taken the course embraced in the alternative on appeal - ie had his Honour provided a modified MCA direction to the effect that the behavioural change evidence might demonstrate consistency thereby buttressing JS's credibility provided that the jury was satisfied that was the only inference reasonably open on the evidence as a whole - the direction would have enhanced, considerably, the use that the jury may have made of that evidence in a manner adverse to the appellant. The trial judge's direction as given was advantageous to the appellant so far as, in effect, it invited the jury to pass over the behavioural change evidence and concentrate on JS's evidence of his interactions with the appellant. The trial judge's direction satisfactorily overcame the shortcomings in the prosecutor's additional observations.
The course adopted by the trial judge meant that his Honour provided no specific directions about the matters I have referred to at [70] above. I consider that no such directions were required given the way the trial judge invited the jury to approach the evidence of change in behaviour.
A direction of some type might have been required if there was a perceptible risk that the jury might fail to appreciate the possibility that other inferences could be drawn from the evidence of change in behaviour. There was no feature of the behavioural change evidence which might affect its reliability and weight which might not have been apparent to the jury and in respect of which the courts have special knowledge or experience. In particular, the matter pressed with the most force on appeal - the alternative explanation for the change in behaviour as presented by JS's exposure to K's sexual offending - was a matter that was obvious to the jury given the evidence and what was otherwise said in the closing address of counsel for the defence as repeated by the trial judge.
In circumstances where the trial judge did not direct the jury that the behavioural change evidence could be used to buttress JS's credibility, and instead directed the jury to concentrate on the direct evidence as to the alleged sexual offending, further direction or warning as to the behavioural change evidence - including how it might be used and the limitations of the evidence - was not necessary to avoid a perceptible risk of a miscarriage of justice. My conclusion that there was no perceptible risk of miscarriage of justice in the course adopted by the trial judge is fortified by the position taken by the appellant's experienced and competent defence counsel at trial in not seeking any further direction. Moreover, on appeal the issue as to the possible misuse of the behavioural change evidence as consistency evidence was not what initially informed senior counsel for the appellant's attack on the direction. It was an afterthought in reply. That also fortifies my conclusion that there was no perceptible risk of miscarriage of justice in the course adopted by the trial judge.

Conclusion and orders

For these reasons I would dismiss the single ground of appeal.

In the particular circumstances of this case, the trial judge did not err in law by failing to provide the jury with an appropriate direction about the use they could make of JS's and LS's evidence about JS's change in behaviour proximate to the alleged offending. Having, in substance, confined the use of the evidence to no more than potentially explaining the lack of any contemporary complaint, no further direction was required. Moreover, a direction of the sort contended for on appeal would have been disadvantageous to the appellant and might have confused the jury.
The ground advanced on appeal was reasonably arguable in the sense that it had a rational and logical prospect of succeeding. The appellant should have leave to appeal but the appeal should be dismissed.
I would order that:
1.The appellant is granted leave to appeal on ground 1.
2.The appeal is dismissed.

HALL J:

I have had the benefit of reading, in draft, the reasons of Vaughan JA. I have come to a different conclusion. In my view the appeal must be allowed, the convictions set aside and a retrial ordered.
As Vaughan JA has set out the State's case at trial, the appellant's case and the relevant evidence, it is unnecessary for me to do so except to the extent necessary to explain my reasons.
This was a case in which the credibility of the complainants was the critical issue. The only witnesses as to the facts relevant to counts 1 ‑ 4 were DB and the appellant. The only witnesses as to the facts relevant to counts 5 ‑ 8 were JS and the appellant. The complainants said that the sexual activity referred to in the counts had occurred, the appellant denied that any such activity had occurred. In respect of each group of offences the jury could not find the appellant guilty unless they were satisfied beyond reasonable doubt that the evidence given by DB, in respect of counts 1 ‑ 4, and JS, in respect of counts 5 ‑ 8, was true and accurate.

Where a charge depends critically upon the credibility of a single witness, often a complainant in a sexual case, special care is required in instructing the jury about evidence that is relevant only to bolster the credibility of that witness. Directions must be tailored to the circumstances of a particular case. This will include taking into account suggestions or submissions made to the jury in closing addresses.
In this case the State adduced evidence of behavioural changes exhibited by JS. That evidence came from JS and his mother, LS. The evidence of LS, in particular, was dramatic and vivid. It was likely to make an impression on the jury; defence counsel in her closing address referred to LS as 'an impressive witness'. That was particularly so bearing in mind that this was a relatively short trial. Evidence of this nature may be used to explain why a complaint was not made at an earlier time (context evidence), as independent evidence that confirms the alleged sexual offences (corroboration evidence) or as evidence of conduct which is consistent with the offending and only relevant to the credibility of the complainant (consistency evidence). The trial judge gave the jury directions as to the first use, effectively excluded the second use but made no reference to the possible use of the evidence in assessing the credibility of JS.
The prosecutor in closing address described the evidence of LS as 'very significant'.[122] He said that although it was not possible to prove that the change of behaviour was causally related to the abuse, he did suggest the change should not surprise the jury if the abuse had occurred. The implication was that the change was, at least, consistent with the abuse, and therefore relevant in assessing the credibility of JS.
[122] ts 22 (24/10/2019).
There were, however, significant problems with the use of the evidence as consistency evidence. In particular, some of the behavioural conduct was of a general nature that might not necessarily be considered consistent with sexual abuse. There were also difficulties as to the timing of some of the conduct as compared to the time of the alleged offences. That is, the conduct had occurred over a period of years and not all of it could be placed close in time (and after) the alleged offences. Furthermore, at least some of the changes could be explained by unrelated abuse of JS by another man. Those problems were not mentioned by the prosecutor. The change of behaviour evidence was referred to by the prosecutor as if it all fell into the same undifferentiated category.
In the circumstances of this case the behavioural change evidence was not capable of being used to support JS's credibility. An express warning against such use was required. The need for such a direction was made particularly necessary given the invitation by the prosecutor to use the evidence in this way. Even if it had been open to use the evidence as consistency evidence, the circumstances required that the jury be directed as to the difficulties and deficiencies of the evidence.
In the absence of any directions in this regard there was a perceptible risk that the jury would use the evidence in an inappropriate way when assessing the credibility of JS. There is a real possibility that this affected the outcome in respect of counts 5 ‑ 8. Furthermore, since the evidence was cross‑admissible, that is it was left to the jury that the similarity of the incidents referred to by the two complainants made it more likely that they were both telling the truth, there is also a real possibility that any assessment of the credibility of JS could have had a consequential affect upon the assessment of the credibility of DB.
An error of law has been established. Leave to appeal should be granted, the appeal allowed, the convictions set aside and a retrial ordered. My detailed reasons for coming to that conclusion follow.

Prosecution case

The offences the subject of counts 1 ‑ 4 were alleged to have occurred between 1 October 1989 and 1 January 1990. The offences the subject of counts 5 ‑ 8 were alleged to have occurred on an unknown date in 1989. Each group of four offences related to a single incident. DB gave the evidence relevant to counts 1 ‑ 4 and JS gave evidence relevant to the counts 5 ‑ 8.
JS and DB met in 1989 when they were both aged about 10 and attending the same school. They became friends and often played together in bushland which surrounded houses in the area. The appellant befriended JS and, through him, came to also know DB.
DB gave evidence that the incident the subject of counts 1 ‑ 4 occurred towards the end of the year he was in year 6 or the beginning of the following year. The appellant was naked on a couch pretending to be asleep when JS and DB came into his house. JS and DB proceeded to masturbate the appellant and performed oral sex. The appellant then masturbated himself to ejaculation.[123]
[123] ts 199 ‑ 200 (21/10/2019).
Counts 5 ‑ 8 relied on JS's evidence. JS said that an incident occurred during the school holidays in 1989 at the appellant's house. JS and DB looked at pornography at the appellant's house and then went to the appellant's bedroom. The two boys and the appellant got undressed and were under the covers of the appellant's bed. JS said that the appellant performed fellatio on JS and DB and, at the instigation of the appellant, JS performed fellatio on the appellant and DB and DB performed fellatio on the appellant and JS.[124]
[124] ts 72 ‑ 73 (21/10/2019).
JS said that sexual activity with the appellant continued for at least two years. At some point in about 1991 or 1992 JS met a man (K) who was living with the appellant at the time. JS was then in year 8 or 9 and about 12 or 13 years old. He formed a sexual relationship with K at K's instigation.[125]
[125] ts 91 ‑ 92 (21/10/2019).

Behavioural change evidence

JS was asked in evidence whether the offending had an impact on his behaviour. He said that it did, in that he acted in an overtly sexual way towards some of his friends. He later clarified that this was related to a single occasion on which he and DB had engaged in sexual activity at DB's home.[126]
[126] ts 81 (21/10/2019).
JS also said that his behaviour towards his parents became more erratic. He described himself as being irrational, having nightmares and stealing things. He said that he lied and self-harmed and was not interested in school.[127] He was taken to psychologists and admitted as a patient at Princess Margaret Hospital. He did not inform medical staff of the sexual activities with the appellant or K because he believed he would get into trouble.[128]
[127] ts 93 (21/10/2019).
[128] ts 94 (21/10/2019).
LS, the adoptive mother of JS, gave evidence that JS came to live with her and her husband as a foster child in 1981 when he was three years old. He was formally adopted some years later. There were four other children in the family. LS said that JS was a friendly and outgoing child without problems until the family moved to another suburb in 1989.[129] At that time JS started to behave in ways that were described as unusual.
[129] ts 165 (21/10/2019).
The relevant part of LS's evidence in examination‑in‑chief is as follows:[130]
[130] ts 166 (21/10/2019).
At some point did that change?---Yes.
And can you put a kind of place or a time on that?---After we moved to [a northern suburb] and he started at [the northern suburb] School we noticed – well, we didn't notice, there were things happening at home with [JS]'s behaviour that were unusual.
What were things – what – what unusual things were happening at home after you moved to [the suburb] in [JS]'s behaviour?---The first thing that happened was he – he started having really terrible nightmares and they were really bad. And he would start screaming, would run round the bedroom, pull the bookcase over, climb on the bed and be trying to climb up the wall. And he used to be not quite awake but screaming.
Did he ever leave the house at night?---No, he didn't because we were so frightened that he would that we put a bolt on the front door at the very top because we had a swimming pool out the front and we were afraid. We didn't know how it was going to escalate so we wanted to keep him safe.
Did [JS] – did [JS] engage in any art or craft or drawing?---He – he liked drawing and he started to draw pictures that were quite disturbing to us. He started drawing pictures as if it was like a monster. He – and this monster would have knives stuck in him. There'd be chains wrapped around this monster. There'd be blood dripping and it was quite a bit frightening for us to see these. We had no idea how to deal with this.
Did any of your other four children have nightmares like [JS]'s?---No.
Any of your other four children draw disturbing images like - - -?---No.
- - - the ones you are describing?---No.
No. Did you still have an interaction with the government department, Community Services Child Welfare, whatever it was called?---Yes, we did.
Okay?---Because [JS] was still fostered so we contacted them at one time and asked for some advice because we didn't know how to handle what was happening.
Did you – did you take him anywhere - - -?---He - - - - - - to see any professionals?---Yes. [JS] was taken to see psychologists and he was admitted into Princess Margaret Hospital at one time and was there – was there for two weeks.
Did [JS] engage in any behaviour in relation to his brother's or sister's toys that disturbed you?---He – he chopped off all the feet and hands of his sister's Barbie dolls.
I think you've said [JS] went to [a northern suburb] High School?---Yes.
That's the local area state school?---Yes.
Okay. And he started school at the usual age for doing so?---Yes, in year 8.
Okay. Did you ever observe any, and I don't mean in private, any sexualised behaviour on the part of [JS]?---Yes, we – we did.
Where – where was that? And again, I don't mean in his bedroom?---He – it was in the lounge room while the – the children – the – two of the other children were in there watching television with him and it was in the back of the car when we were going out, going shopping, going to church.
And what kind of behaviour did you see in those places?---He – he was masturbating.
Okay. And who else was in the lounge room when he did this?---Sorry. It was [SS] and [KS], the two younger ones.
And who would have been in the car when he did this?---Pardon, sorry?
Who would be in the car when he did this?---Well, [SS] and [KS] and maybe [IS] as well. [RS] was a lot older at that stage so - - -
All right?--- - - - he was often not with us.
We've heard evidence that at some point [JS] moved out of your family home - - -?---Yes.
- - - into what's variously been called a group home or a halfway house?---Yes.
Did that happen? Was there a time when he moved out of your home into a facility of that nature?---Yes, he was 15 at that time.
Now, was he still at school or not?---Yes. Yes, I think so.
Whose choice was it for [JS] to move out of home, [LS]?---It was both myself and my husband.
And you'd adopted three children?---Yes.
And you had two more. What – what was going on that prompted you to decide this with your husband?---Pardon, sorry?
What – why did you do – why did you – why did you decide that [JS] had to move out?---Okay, sorry. Well, one night my husband and I took the dog for a walk and all the children were there, including the eldest one who was quite old then. And when we got home my daughter, [SS], said to me that [JS] had been in her bed and he had hurt her.
And I just – I just spoke to my husband and said, 'I can't do this anymore. You know, we need extra – [JS] needs extra help that we can't give.'
Did you ever ascertain what kind of hurt it was?---No. I didn't want to know actually.
In cross‑examination LS gave the following evidence:[131]
And then your evidence was when he went to [the northern suburbs] Primary School, he started to have behavioural issues. Is that right?---Yes.
He got in trouble for stealing at school, didn't he?---He did.
That starts pretty much as soon as he went to [the school] that he got into trouble?---That was in September of that year. I know - yeah, I can only – I know that for sure because of another event that happened for me.
You were told some things about [JS]'s birth mother, weren't you?---Yes. We were told that she suffered from schizophrenia and had paranoid delusions, and that she lived in a hostel.
And the purpose of [JS]'s admission into Princess Margaret Hospital was to do an assessment to see if he was suffering similar conditions. Isn't that right?---Yes.
Now, when [JS] was having the nightmares - - -?---Yes.
Sorry, just to find the reference in the report. So when he was having the nightmares, you spoke to [JS] about that? About his nightmares?---I should imagine so
And he told you that the monster in his nightmares would be standing at his desk at school?---He did say that once.
[131] ts 174 (21/10/2019).

Closing addresses

In his closing address the prosecutor referred to the fact that JS reported the matters to the police on his 39th birthday but that the events had influenced his life for years before then.[132] He then referred to the evidence of LS:[133]
The evidence of his mother, [LS], is very significant here. The boy she and her husband [FS] fostered and then adopted had been a friendly, cheerful child when they lived in Heathridge, but when they moved to [the northern suburb] it all changed. He got these awful nightmares about monsters. He said the monster was in his school I think my learned friend got [LS] to say. Well, the monster lived near the school.
He started misbehaving. He started stealing. He started overtly engaging in sexual behaviour. He started masturbating in the presence of his brothers and sisters in the lounge room, in the car. That's something [JS] didn't remember doing. He was almost in tears as he recounted to you that it had never been explained to him why he was kicked out of the family home and [LS] was in tears when she told you how hard it was for her and [FS] to realise that [JS] needed more help than they could give. The catalyst seems to have been a complaint [JS]'s sister made against him which [LS] deliberately didn't get to the bottom of. She just said, 'Look, it's got to stop. He must live somewhere else.'
Now, I'm not asking you to conclude that the deterioration in [JS]'s mental state, his behaviour and his relations with his family deteriorated because of the sexual abuse. I can't prove that these things are causally linked. What I can say to you, though, is this. Given what you've heard about the behavioural problems he was having at home at [the northern suburb] that weren't there at [the earlier home], are you surprised to find that he says he was sexually abused at Edgewater?
Does it shock you that a boy with behavioural problems turns out to be saying, credibly and with corroboration from another child, that he was being sexually abused at the time? I don't think it should surprise you. I think it's what you'd expect. Now, [DB] didn't experience any such ill effects. You heard nothing to the effect that it poisoned his childhood. But [DB]'s interactions with the man were not as long.
[132] ts 22 (24/10/2019).
[133] ts 22 ‑ 23 (24/10/2019).
The only reference in defence counsel's closing address to the behavioural issues was as follows:[134]
What I'd say about [LS] is that she was an impressive witness. We could all hear the pain in her voice and appreciate the suffering that she's gone through.
To have to kick your adopted son out of home at the age of around 15 years and send him to a group home is clearly something that was very hard for her and you'd have little difficulty accepting her evidence, I'd suggest. In this regard, I should note her evidence about [JS]'s behavioural issues at schools, and nightmares. We all heard about that.
And he told her that the monster in his nightmares would be standing at the desk at school. I'd say that's quite an interesting comment and something significant for you, that the monster was at school, not opposite the school, at the school.
[134] ts 40 (24/10/2019).

Discussion with counsel

Before the trial judge directed the jury he invited counsel to make submissions as to what directions he should give to the jury. The following exchange occurred:[135]
[135] ts 461 ‑ 462 (21/10/2019).
DUNGEY, MR: Yes. There's one other suggestion, your Honour. I was in a trial recently before Judge Troy and the question arose as to the evidence about decisions, things that had happened to the complainant as a result of her saying she'd been sexually abused.
And in that case it was her marrying exceedingly young at the age of 17 to somebody and she said that was to get away and Judge Troy thought it appropriate to give a circumstantial evidence direction about that.
Here we have all this stuff from [LS] about - - -
PRIOR DCJ: Behaviour.
DUNGEY, MR: - - - his behaviour changes, masturbation, misbehaviour. That may call upon your Honour to caution the jury about how they deal with that because they'd have to be satisfied that it could only be used in a particular way. They couldn't automatically reach any deduction about what led to that.
PRIOR DCJ: I'm reticent to give a circumstantial direction. I understand what you're saying - - -
DUNGEY, MR: Yes.
PRIOR DCJ: - - - because ultimately this is a pretty black-and-white case.
DUNGEY, MR: It is.
PRIOR DCJ: It's credibility of [JS] and [DB] from the State's perspective versus credibility of Mr Akkerman, notwithstanding Mr Akkerman bears no onus of proof in the Liberato issues.
I just don't want to – because I've got to give about five other directions about relationship evidence, a Longman direction, delay in complaint, a Palmer, prior inconsistent statements and there may be one other I want to tell them.
DUNGEY, MR: Certainly, your Honour. I just raise it - - -
PRIOR DCJ: Yes. Well, I'll think about it overnight, but I understand what - - -
DUNGEY, MR: I think my learned friend wants - - -
PRIOR DCJ: What do you think about that, Ms Oliver?
OLIVER, MS: Your Honour, I think they do need to get some sort of warning that they can't use it to reason that he was abused because - - -
PRIOR DCJ: Okay.
OLIVER, MS: - - - there is no evidence to draw that link, but I wouldn't say a circumstantial direction is required.

Summing up

In summing up the trial judge made it clear to the jury that the critical issue was the credibility of the complainants:[136]
Now, it's pretty obvious in this trial, credibility and believability is a key, fundamental issue in this trial because you've got three, significant witnesses, [JS], [DB], and Mr Akkerman, who gave evidence, and their credibility and believability is something you're going to have to consider. Credibility concerns honesty. You must also – so when you're considering honesty, a witness may be honest but have a poor memory, or otherwise be mistaken…
So you cannot convict the accused man, Mr Akkerman, of any counts on the indictment, unless you're satisfied beyond reasonable doubt as to the truthfulness, accuracy and reliability of the evidence of [JS] or [DB] in relation to that matter.
Now, when I say that, of course there's other evidence, exhibits, and other witnesses, I'm not suggesting, for one minute, you disregard all the other evidence. But they are significant witnesses and you will need to make credibility assessments.
[136] ts 476 (21/10/2019).
The trial judge referred to the behavioural change evidence when summarising the prosecution case. In particular, after referring to the delayed complaint he said:[137]
[JS's] own evidence about his behaviour changing as a child. He misbehaved when he was living in [the northern suburb] so effectively he was going through a troubled period of his life so that may to some extent explain why they didn't complain or there's a delay in the complaint.
[137] ts 502 (21/10/2019).
Later the trial judge said the following in regard to the behaviour evidence:[138]
[138] ts 512 ‑ 513 (21/10/2019).
Now, you heard both [JS] and [LS] give evidence about his change in behaviour when they were living in Edgewater, so the change in [JS's] behaviour as a child, and then eventually he went to a hostel when he was 15.
Be careful when you're considering that evidence. Don't speculate about this. The only evidence you have about what may have caused his behavioural change is [JS] himself. Concentrate on his evidence about what his interaction was with Mr Akkerman. Are we satisfied beyond reasonable doubt the acts of sexual abuse occurred between [JS] and Mr Akkerman?
Now, finally, the State asks you to accept [LS] and [DB] as witnesses of truth. I think you were told that right at the outset by Mr Dungey on Monday at mid-morning when he gave his opening address.
They of course are the only witnesses against Mr Akkerman as to the happening of the events alleged in the indictment. Whilst there's been other evidence, no one has confirmed or corroborated [JS's] or [DB's] evidence as to the offences themselves. Of course, they confirm each other's evidence as to this, but there's no other witnesses who were there at the time.
Therefore, the position is that you must be satisfied beyond reasonable doubt about the truthfulness, the accuracy and reliability of their evidence, [DB] and [JS], before you could convict Mr Akkerman of any of the charges.
Because of the critical nature in this case of [JS's] evidence and [DB's] evidence and because of the seriousness of the allegations they make and factors to which I'll turn to, you should scrutinise both their evidence with special care.
You should take carefully into account that these events are alleged to have happened some 30 years ago. They're allegations of serious sexual crimes. No complaint was made around the time. There's no corroboration or confirmation of the evidence of [JS] and [DB] and there's no other evidence that the events happened.
Of course, the exception is both [JS] and [DB] gave evidence that they were both present together when the accused, Mr Akkerman, committed the eight alleged offences, so they corroborate each other.

Ground of appeal and submissions on the appeal

The ground of appeal is:
The learned trial judge erred in law by failing to give the jury an appropriate direction about the use they could make of the evidence about the complainant JS's change of behaviour proximate to the offending.
The appellant submitted that in the circumstances of this case the trial judge should have given a direction to the jury about the change of behaviour evidence that was in accordance with the type of direction referred to in MCA v The State of Western Australia.[139] This submission was based on an assumption that the jury could have used the change of behaviour evidence to infer that the offences occurred, that is as corroboration evidence.
[139] MCA v The State of Western Australia [2019] WACSA 22.
In MCA the complainant was 'repeatedly cross-examined' as to the reasons why she had not complained to her mother at the time the sexual abuse was occurring. Evidence of a change of behaviour of the complainant at the relevant time was held to be relevant and admissible because it could explain why she had not complained to her mother and because her 'behaviour was consistent with being sexually abused as alleged'. The court held that, in an analogous manner to evidence of distress, evidence of a change of behaviour which is contemporaneous with alleged sexual offending is not merely admissible to show consistency of behaviour, it is also admissible to corroborate the evidence of the complainant, at least where the jury is satisfied that it is the only reasonable explanation for the behaviour.
The directions given by the trial judge in MCA were similar in form to those given where there is evidence of distressed state. In particular, the jury was directed that before they could conclude that the change in behaviour was consistent with her being dealt with in the way alleged, they had to be satisfied that it was the only reasonable inference to be drawn from the evidence. In context it is clear that this use of the word 'consistent' was intended to refer to circumstances where the evidence was being relied on, like distress evidence, as evidence that independently corroborates the evidence of the complainant.
The appellant submitted that the change of behaviour evidence in this case was analogous to that in MCA and should have attracted a similar direction.[140] It was suggested that the closing submissions of the prosecutor had effectively invited a course of reasoning that the change of behaviour evidence was corroborative of the evidence of JS.[141] The failure to give such a direction was said to be an error of law.
[140] ts 7 (09/12/2020).
[141] ts 8 (09/12/2020).
The respondent submitted that the proper interpretation of the prosecutor's closing submissions was that it was accepted that no causal connection between the alleged offending and the change of behaviour could be established.[142] That was an implicit acceptance that the evidence could not be used as independent evidence that corroborated JS. The prosecution only relied on the evidence to explain the lack of contemporaneous complaint and as evidence that was consistent with the claims of abuse (in the sense that it only went to the issue of credibility). The trial judge, accordingly, directed the jury that there was no evidence that could corroborate JS (other than that of DB).[143] In those circumstances there was no risk that the jury would use the change of behaviour evidence as corroboration and no occasion for a direction like that given in MCA.
[142] ts 19 ‑ 20 (09/12/2020).
[143] ts 17 (09/12/2020).

Merits of the appeal

The change of behaviour evidence was potentially relevant in three ways:
1.It could explain why JS had not made a complaint about the conduct until he was an adult (context evidence).
2.It could independently confirm or corroborate that the offending conduct had occurred (corroboration evidence).
3.It could be viewed as being consistent with the occurrence of the offending and thus supportive of JS's credibility (consistency evidence).
As to the first use of the evidence, this was accepted both at trial and on appeal. The trial judge directed the jury in respect of this possible use and no complaint is made about that part of the directions.
In regard to the second possible use, MCA can be distinguished because in that case the prosecutor relied on the change of behaviour evidence as being corroborative of the fact of the alleged offending and the evidence was left to the jury on the basis that it could be used in that way. In contrast, in the present case the prosecutor disavowed any such use. In saying that it could not be proved that the change of behaviour was caused by the offences the prosecutor implicitly accepted that the evidence could not be used as independent corroboration.
Any risk that remained that the evidence would be used as corroboration was effectively removed by the trial judge's repeated directions to the jury that there was no evidence that could corroborate that of JS (other than the evidence of DB). The necessary implication was that the change of behaviour evidence could not be used as independent evidence corroborative of the occurrence of the offences. In those circumstances there was no occasion for a direction in the form approved in MCA. In saying this I recognise that this assumes that the jury would understand that in saying that there was no corroboration the judge meant to exclude the use of the behavioural change evidence as evidence that could independently confirm the alleged offending. That may be a large assumption and it will often be better to give a direction that expressly refers to specific evidence. However, the fact that in this case the prosecutor disavowed use of the evidence as corroboration meant that the more general direction was adequate. This conclusion is fortified by defence counsel taking no exception to his Honour's direction.
That leaves the third possible use of the evidence. That is, that the behavioural change evidence could be used to demonstrate consistency of behaviour. Even if it could not be proved that the only reasonable inference was that the change was caused by sexual abuse, the behaviour could be relevant if it was consistent with the occurrence of sexual abuse. That is, that the evidence could enhance or bolster the credibility of the complainant's evidence because it was consistent with his evidence of the sexual offending. This use of the evidence is analogous to the use that can be made of recent complaint evidence. Such evidence does not constitute separate and independent evidence that corroborates the complainant's evidence of the offending, rather it is relevant in assessing the credibility of the complainant.
The use of change of behaviour evidence in this way, whilst open in some circumstances, is more problematic than recent complaint. Recent complaint by its nature has an obvious connection to the claims made by the complainant. Change of behaviour evidence requires an indirect reasoning process that involves considering whether the change is such as could be explained by offending such as that alleged. Where the offending is alleged to have taken place over an extended period there may be issues as to when the change of behaviour occurred and whether a temporal connection can be drawn.
The trial judge did not address this possible use of the evidence. It may well be that his Honour considered that by telling the jury not to speculate as to the causes of the change of behaviour and reminding them that the central issue was the credibility of each of the complainants, the effect would be to limit use of the evidence to explaining why JS had not complained at the time. However, no such limitation was expressly stated. The adequacy of those directions has to be viewed in the light of the submissions made by the prosecutor in closing.
The jury were invited by the prosecutor to take into account the change of behaviour evidence when considering the credibility of JS. The relevant part of the prosecutor's closing could only be interpreted as meaning that whilst no causal link between the offending and the change of behaviour could be established, those changes were to be expected if the offending had occurred. That is, that the changes of behaviour were consistent with the evidence given by the complainant JS. The trial judge did not comment on that suggestion, nor did he expressly exclude the evidence being used in that way.
The evidence given by JS's mother, LS, in regard to the behavioural changes was vivid and likely to have made an impression on the jury. It included references to nightmares, stealing at school, drawing pictures of monsters, sexualised behaviour in the presence of other children and being admitted to a hospital. Unless expressly directed not to do so, there was a very real likelihood that the jury would rely on these incidents, if not as independent corroboration of the offending, at least as evidence which was consistent with what JS said had occurred. In this respect the evidence had the potential to be used to enhance and bolster the credibility of JS.
It is true that the trial judge directed the jury on a number of occasions that the critical issue was the credibility of the complainants. However that was not a direction that was likely to obviate the risk I have referred to. The use of the behavioural change evidence as being consistent with that of the complainant is only open because it is relevant to credibility. Directing the jury to concentrate on the issue of the credibility of the complainants, and in particular JS, did not either expressly or by implication exclude the use of the behavioural change evidence as consistency evidence.
The effect of not directing the jury in this regard was to leave them without guidance as to how the evidence could be used and what matters may be relevant to such use. For behavioural change evidence to be capable of being consistent with sexual abuse it must be at least possible for the behaviour to be so explained. Whilst consistency in this sense may not require a causal connection it does at least require that there be a possible plausible connection.[144] Some behaviours can be of a nature as to indicate a possible cause, others may have very many possible causes. Some of the behavioural changes referred to here such as nightmares, stealing and drawing of disturbing pictures might have such a large number of possible explanations as to make any claim of consistency a weak one. Secondly, the evidence did not place any of the behavioural change incidents clearly into a precise timeframe. According to LS some of the changes had occurred soon after JS commenced at the school in 1989, but others such as the admission to hospital, appear likely to have occurred some years later. There was a real possibility that at least some of the changes referred to occurred after JS met K and became the object of sexual abuse by him. The cumulative effect of these problems made it impossible to use the evidence as consistency evidence at all. Even if it could have been used in this way, it would have been necessary in this case to expressly warn the jury of the weaknesses inherent in the evidence. That necessity was highlighted by the submissions made by the prosecutor in closing. This was not a case where other explanations for the changes were speculative.[145]
[144] In Walsh v The State of Western Australia [2011] WASCA 119 [68] and Di Stefano v The State of Western Australia [2017] WASCA 187 [23] the issue of whether it was necessary to exclude other potential causes for distress where distress is not relied on as corroboration but only to bolster credibility was left open.
[145] As in Di Stefano [25].
In the circumstances of this case there was a perceptible risk that, in the absence of appropriate directions, the jury would use the behavioural change evidence in their assessment of the credibility of JS. Such use was not properly open on the evidence at the trial. In those circumstances the ground of appeal has been made out. The error must flow through to all charges since the evidence was held to be cross‑admissible and the jury were told that the evidence of JS in respect of counts 5 ‑ 8 could be used to support that of DB on counts 1 ‑ 4.

Conclusion

In my view the learned trial judge erred in law by failing to give the jury an appropriate direction about the use they could make of the evidence about JS's change of behaviour.
Leave to appeal should be granted, the appeal allowed, the convictions set aside and a retrial ordered.

I certify that the preceding paragraph(s) comprise the reasons for decision of the Supreme Court of Western Australia.
OE
Associate to the Honourable Justice Vaughan
23 MARCH 2021