THE SIGNIFICANT PROBATIVE VALUE OF TENDENCY EVIDENCE.

• Date: 01 January 2019
• Author: Hamer, David

Contents I Introduction A Overview II Legal and Factual Sides of the Probative Value Threshold A The Basis and Level of the 'Significant Probative Value' Threshold B Probative Value Assessment is Factual, Logical and Empirical, Not Legal III Probative Value, Proof and Context A Avoiding the Conflation of Probative Value and Proof B Evidential Context and the Fact in Issue IV The Relative Consistency Structure of Probative Value A The Consistency and Inconsistency Elements B Commission, Identity and Relative Consistency V Application of the Relative Consistency Model A Consistency, Predictability, Similarity and Frequency B The Royal Commission on Persons and Situations C Inconsistency, Unusualness and Similarity VI Conclusion I Introduction

Tendency evidence in criminal cases typically consists of evidence of a defendant's other misconduct, adduced to support an inference that the defendant has a tendency towards such misconduct, and so is more likely to have committed the charged offence. It is excluded by the tendency rule in s 97 of the Uniform Evidence Law ('UEL') (1) and must possess 'significant probative value' to gain admission. Further, under s 101(2), the probative value of prosecution tendency evidence must substantially outweigh the risk of prejudice. (2)

The admissibility of tendency evidence is hotly contested in child sex offence cases in particular. The offences are generally committed in secret, and victims often delay before reporting the abuse, resulting in a loss of evidence. (3) The prosecution may be left with little evidence other than the complainant's allegations. Tendency evidence of other alleged victims can be crucial in the prosecution proving its case beyond reasonable doubt. The stringency of the exclusion rule in child sex offence cases came under close scrutiny in two key forums in 2017: the Royal Commission into Institutional Responses to Child Sexual Abuse ('Royal Commission') in its Criminal Justice report identified the exclusion of other allegations as 'one of the most significant issues, (4) and the High Court in Hughes v The Queen ('Hughes') conducted a detailed examination of the probative value of other allegation evidence on child sex offences charges. (5) Both discussions reveal the pressures for opening up admissibility of tendency evidence.

This article examines the probative value of tendency evidence from the perspectives of probability theory and behavioural science. It pays close attention to the arguments of the Royal Commission and the High Court in Hughes. However, the implications extend beyond child sex offence cases to criminal cases more broadly. (6) It argues that tendency evidence has greater probative value than has traditionally been appreciated. This has two important implications. Most immediately, tendency evidence, properly assessed, will often have a good chance of satisfying the probative value admissibility requirements in s 97 and s 101. More fundamentally, the significant probative capacity of tendency evidence undermines the policy basis for exclusion. The traditional concern about juries overvaluing the evidence appears exaggerated, and exclusion will carry an elevated risk of mistaken acquittal. The elevated probative value requirements for tendency evidence should be reconsidered.

Competing views about the probative value of tendency evidence were expressed in Hughes. Robert Hughes, the 1980s Hey Dad..! TV star, was convicted for a series of child sex offences against five complainants. The prosecution had relied heavily on tendency evidence. It argued that the complainants' allegations were cross-admissible--that each charge derived support from evidence of similar misconduct provided by the other four complainants. Further tendency evidence of uncharged misconduct from six other witnesses was also admitted. (7) The defendant appealed unsuccessfully to the New South Wales Court of Criminal Appeal ('NSWCCA') (8) and then to the High Court of Australia, arguing that the evidence of other alleged victims and complainants did not possess the 'significant probative value' required by s 97(1)(b).

Much of the High Court's discussion focused on the extent to which the misconduct alleged in the challenged tendency evidence--in order to acquire significant probative value on a particular count--would need to closely resemble the misconduct charged in that count. On one view, the High Court was required to make a choice between the stringent Victorian approach and the more open New South Wales ('NSW') approach. (9) In Velkoski v The Queen ('Velkoski'), (10) the Victorian Court of Appeal ('VSCA') suggested that 'sufficient similarity or distinctiveness in the features of the proposed tendency evidence' may require something '"remarkable", "unusual", "improbable" [or] "peculiar"'. (11) The Victorian court criticised statements of the NSWCCA that the other misconduct need not be 'closely similar' (12) with the charged offence for lowering the admissibility threshold 'too far'. (13)

Shortly after Velkoski, the NSWCCA in Hughes indicated it did 'not accept that the language used by the Victorian Court of Appeal represents the law in New South Wales.' (14) The NSWCCA upheld the admissibility and cross-admissibility of the allegations of complainants and other tendency witnesses, notwithstanding that: the complainants' ages ranged from 6 to 15 with another alleged victim in her early twenties; that they were in a variety of social and professional relationships with the defendant; and that they gave evidence of various sexual touching and exposure behaviours, in various contexts. The defendant appealed to the High Court, arguing that the Court should adopt the Victorian demand for specificity in Velkoski; recognise that the alleged behaviours were too 'dissimilar'; (15) and recognise that the alleged tendency was at too high a level of 'generality' (16) for the evidence to acquire significant probative value and gain admissibility. (17) For example, the defendant argued that

there was a 'world of difference' between the evidence concerning EE (count 10), who was 15 years old and whom the appellant encouraged to commit indecent acts in a park and in a driveway, and the evidence concerning SH (counts 3 to 6), which involved intrusive acts 'in a darkened bedroom, in her bed, when she was only six, seven or eight'. (18) The Victorian Director of Public Prosecutions intervened in the High Court appeal to support the more open NSW approach. (19)

The High Court dismissed Hughes' appeal by a narrow 4:3 margin. The majority judgment of Kiefel CJ, Bell, Keane and Edelman JJ upheld the admissibility determinations of the trial judge and the NSWCCA, expressly disapproving Velkoski as 'unduly restrictive' (20) and inconsistent with the legislative scheme. (21) There were three dissenting judgments. Nettle J, in the longest judgment, defended the VSCA's approach as orthodox, (22) and criticised the NSWCCA for '[going] so far in lowering the bar' without 'justification in principle or as a matter of statutory interpretation'. (23) His Honour would have rejected the admissibility of much of the tendency evidence as too dissimilar and overturned all the convictions. (24)

Gageler J indicated that 'to consider how the tendency rule is best to be applied', (25) the Court should be 'informed by social science data'. (26) Unfortunately, '[n]o party or intervener in the present appeal sought to direct attention to data or scholarly work bearing on actual probabilities'. (27) In the absence of that guidance, Gageler J adopted a 'conservative approach'. (28) However, Gageler J only viewed the evidence relating to complainant EE (the tenth count against the appellant, mentioned above), as being too dissimilar from the others to sustain cross-admissibility (although this was sufficient to require all convictions to be quashed). (29) Gordon J, in a short judgment, agreed with the reasoning of Nettle J and the orders proposed by Gageler J and Nettle J. (30)

Following Hughes, the Royal Commission noted, with approval, that the decision 'is likely to lead to the greater admissibility of tendency evidence and to more joint trials where tendency evidence is cross-admissible, particularly in Victoria'. (31) However, the Royal Commission doubted whether the decision 'provides sufficient guidance' to courts, (32) indicating that the decision was not as broad as '[the Royal Commission considered] necessary' (33) and recommending that admissibility be opened up further. (34) The examination of the probative value of tendency evidence in this article supports the Royal Commission's position. Tendency evidence is more probative than traditionally appreciated by the courts, calling into question the exclusionary rule as it currently operates. While the High Court decision in Hughes is a step in the right direction, the law requires more fundamental reform.

A Overview

This article provides a close examination of the issue at the heart of the Hughes appeal and the Royal Commission's recommendations: the probative value of tendency evidence. The analysis aims to remedy the gap identified by Gageler J and draws upon the probabilistic logic of probative value and an empirical understanding of criminal behaviour. Part II begins by examining the s 97 probative value requirement. Interpretations of the test advanced in Hughes are considered in Section A. While the level of the threshold is a legal question, Section B argues that whether or not evidence meets the threshold is a factual question, determined by the logical analysis of appropriate empirical data.

Part III commences the analysis by distinguishing probative value from the related concept of proof. The two concepts are regularly conflated by opponents of admissibility. This can lead to excessive probative value demands and hinder understanding of the probative contribution tendency evidence can make. While evidential context...