In R v A (CA 123/04, 16 December 2004), the Court of Appeal considered whether the evidence of a registered psychologist called at trial complied with s 23G of the Evidence Act 1908, which governs the admissibility of expert evidence in child sexual abuse cases.

The section authorises the giving of expert evidence on the question of whether a complainant’s behaviour was consistent or inconsistent with that of a sexually abused child of similar age. The expert may not give an opinion under the section as to whether or not the child has been abused, or whether or not the accused is the perpetrator.

In R v A, the Court suggested that “you’ve got to know how likely a behaviour is if there’s sexual abuse, and how likely it is if there’s no sexual abuse. That’s the proper measure of its probative value,” said Bernard Robertson, co-author of Interpreting Evidence: Evaluating Forensic Science in the Courtroom and chapters of Cross on Evidence.

According to Robertson, the “bald statement” that the evidence is consistent with sexual abuse is of no probative value and is “hence irrelevant”.

Commentators claim the evidence given as to whether behaviour was consistent with sexual abuse in the infamous Christchurch Civic Crèche case R v Ellis under s 23G(2)(c) would not pass the standard set by R v A. “Cases such as these should be the subject of Governor-General’s references to the Court of Appeal, because they’re miscarriages of justice by which hundreds of people have gone to jail,” Robertson said.

University of Auckland Law School evidence lecturer Scot Optican said that this will “never happen”. “The Court of Appeal tends to approach such cases on an individual basis and almost never suggests that such evidential rulings could operate retrospectively to put hundreds of other trials at risk,” he said.

“However, as with any case, there is always the possibility of defendants bringing new appeals on the basis of R v A and arguing that their trials were unfair,” he added.

Minister of Justice Phil Goff told NZ Lawyer, Lawyers Weekly’s sister publication, “[The case] doesn’t recast the application of s 23G, nor does it restrict the evidence that could be given under it. There is therefore no reason to think that it will have any effect on other cases where s 23G has applied.”

Lynley Hood, author of A City Possessed, the multiple award-winning book on the Ellis trials said, “If the R v A standard was used in Ellis, the case would have been laughed out of court”.

If the R v A yardstick were applied to Ellis, most, if not all of the “behavioural characteristics of child sexual abuse” presented by prosecution expert witness Dr Karen Zelas in her evidence-in-chief would be considered irrelevant and of no probative value, Hood said.

Zelas did not give evidence about other possible explanations for the observed behaviours in Ellis, Hood said. Defence expert witness, Australian psychologist Dr Keith Le Page, argued there was a need to look at the background of the children because other possible explanations for the observed behaviours should be considered.

According to Le Page, it could not be said that behaviours were consistent with sexual abuse unless you looked at all the other factors — “which is exactly what R v A is saying you should do,” Hood said. But he was “attacked” by both the Crown and the judge for going outside the provisions of s 23G.

When the comments by the Crown and the judge in Ellis on Le Page’s concerns are compared with the Court of Appeal’s comments in R v A on the need to explore other possible explanations for the observed behaviours in allegedly abused children, “one is bound to conclude that the jury in Ellis was seriously misled on this point,” Hood said.

Andrea Ruffell is the Editor of NZ Lawyer, Lawyers Weekly’ssister publication in New Zealand