Sometimes, evidence that the accused has been convicted
for committing other offences is admissible to prove that he committed the offence with which he is now charged. Or again, allegations
that he committed other offences may be used to prove that he committed this one. Or, yet again, allegations of offences for which he has been acquitted
may be used as evidence that he is guilty of this one.
This sort of evidence, called similar fact evidence, should only be allowed to be used in exceptional circumstances, for the obvious reason that it will have a tendency to bias the tribunal of fact (usually the jury) against the accused.
It must be said that the current law on similar fact evidence in New Zealand is in need of clarification. This is largely due to the decision of the Court of Appeal in R v Holtz
 1 NZLR 667; (2002) 20 CRNZ 14 (CA), where the criterion for admissibility was held to be whether the probative value of the similar fact evidence outweighs its illegitimately prejudicial effect:"One of the problems with evidence of past conduct, whether labelled evidence of bad character, propensity evidence or similar fact evidence, is the tendency to look for principles of admissibility applicable to all such evidence in all circumstances. At a very general level there is the broad principle that to be admissible the evidence must be such that its probative value outweighs illegitimate prejudice to the accused in having adduced evidence of past conduct that might be given undue weight or used improperly in reasoning towards guilt of the crime charged. It is in the application of that general principle in the circumstances of particular cases that difficulties arise. Often this is because the approach adopted in one set of circumstances is taken as the rule to be applied in a quite different case. Because of the wide variation in circumstances in which the issue calls for consideration, the preferable approach in a particular case is that which determines and weighs probative value and potential prejudice in the circumstances. It is necessary to consider the nature of the evidence, what it is sought to prove, what other evidence there is and its relationship and whether the evidence relates to prior proved offending or to concurrent charges, all against the underlying dangers inherent in propensity or bad character evidence." (para 35)
The so-called weighing of probative value against prejudicial effect is problematic conceptually, and has been criticised in the leading Australian case on similar fact evidence, Pfennig v R
(1995) 182 CLR 461
per McHugh J on the basis that these were "incommensurables", and the Supreme Court of Canada has agreed with his criticism, in R v Handy
(2002) 164 CCC (3d) 481 (SCC); 213 DLR (4th) 385, at paras 148-149. And I have written an article on it: "Probative value, illegitimate prejudice and the accused's right to a fair trial" (2006) 29 Crim LJ 8.
In Phillips v R
 HCA 4 (1 March 2006) the High Court of Australia has confirmed that Pfennig
continues to be the authority on similar fact evidence, binding on Australian courts. It issued a thinly-veiled rebuke to courts that sought to find reasons for departing from Pfennig
, at para 60:"It must be said at once that it is for this Court alone to determine whether one of its previous decisions is to be departed from or overruled …. Of course, in criminal cases it is often necessary for trial judges and Courts of Criminal Appeal to elaborate upon rulings of this Court; to gather together rules expressed in several cases; to apply rules to different facts; and sometimes to reconsider rules affected by later legislation. Within spaces left by the binding determinations of this Court, trial judges and intermediate courts retain their proper functions …. However, these do not extend to varying, qualifying or ignoring a rule established by a decision of this Court. Such a rule is binding on all courts and judges in the Australian Judicature."
One misinterpretation of Pfennig
, alluded to briefly in Phillips
at para 62, is that it is appropriate and sufficient to regard similar fact evidence as a form of circumstantial evidence. This is what had occurred in Holtz
. See Adams on Criminal Law
, Ch2.8.19(5), and my blog entry for 14 October 2004. A danger of that view is that it leaves the process of drawing inferences unelaborated by particular directions to the jury, as authorities on inferences tend to avoid such assistance. It also tempts the court to admit the evidence, as circumstantial evidence is just a category of admissible evidence.Phillips
hold that similar fact evidence must pass a high threshold before it can be admitted (para 79):"Criminal trials in this country are ordinarily focused with high particularity upon specified offences. They are not, as such, a trial of the accused's character or propensity towards criminal conduct. That is why, in order to permit the admission of evidence relevant to several different offences, the common law requires a high threshold to be passed. The evidence must possess particular probative qualities; a strong degree of probative force; a really material bearing on the issues to be decided. That threshold was not met in this case. It was therefore necessary that the allegations, formulated in the charges brought against the appellant, be separately considered by different juries, uncontaminated by knowledge of other complaints. This is what Pfennig and other decisions of this Court require. To the extent that O'Keefe [a Queensland Court of Appeal decision critical of the High Court of Australia's judgments in Pfennig] or other authority suggests otherwise, it does not represent the law. No other outcome would be compatible with the fair trial of the appellant."
Phillips had been charged with 8 counts of sexual offending, and had unsuccessfully sought severance of those. Joinder was permitted on the basis that the evidence on each charge was admissible on the others, as evidence of similar facts. The High Court summarised the evidence and its conclusion in this way (para 56):"The similarities relied on were not merely not "striking", they were entirely unremarkable. That a male teenager might seek sexual activity with girls about his own age with most of whom he was acquainted, and seek it consensually in the first instance, is not particularly probative. Nor is the appellant's desire for oral sex, his approaches to the complainants on social occasions and after some of them had ingested alcohol or other drugs, his engineering of opportunities for them to be alone with him, and the different degrees of violence he employed in some instances. His recklessness in persisting with this conduct near other people who might be attracted by vocal protests is also unremarkable and not uncommon."
Bad technique, indeed, as it got Phillips to court.
The trial judge, and the Queensland Court of Appeal, had reasoned that so many similar complaints could not have arisen by chance, so together they had credibility. The High Court was not so slap-dash. It identified the issue on which the challenged evidence was relevant as being consent, and it pointed out that the non-consent of one complainant could not possibly prove that another had not consented.
One thing this case illustrates is the way judges can lose their reasoning powers in cases of alleged sexual misconduct. There is, in other words, a grave danger of judicial bias (probably unconscious bias) in such cases. In those circumstances, clear rules, rather than discretions, are needed concerning the admissibility of evidence of other alleged misconduct. The Pfennig
rule is that similar fact evidence is not admissible unless there is no reasonable view of it that is consistent with the accused’s innocence. It must have strong probative force, a really material bearing on the issues to be decided; its probative force must clearly transcend its merely prejudicial effect; it must have a sufficient nexus, some specific connection, with the issues; its probative force must be such as to make it just to admit it (Phillips
, para 54). None of those criteria were met in Phillips
It is sad to note that in New Zealand, the Evidence Bill proposes an approach to similar fact evidence (or, in its terminology, "propensity evidence") that applies the probative value/prejudicial effect weighing, criticism of which is noted above. Clause 39(1) of the Bill provides:"The prosecution may offer propensity evidence about a defendant in a criminal proceeding only if the evidence has a probative value in relation to an issue in dispute in the proceeding which outweighs the risk that the evidence may have an unfairly prejudicial effect on the defendant."
This proposal does nothing to improve our law on this point.