Thursday, August 06, 2020

Review: “Expert Evidence About Memory in New Zealand Sexual Violence Trials and Appellate Courts 2001 to 2020” by Suzanne Blackwell, Fred Seymour and Sarah Mandeno (June 2020).


This Report is essential reading for counsel who are considering calling expert psychological evidence with a view to challenging the accuracy of a complainant’s evidence in a sexual violence case. It is also essential reading for any psychologist who has to decide whether proposed testimony in such a case will withstand attack for scientific unsoundness.

 

Its survey of the scientific literature that has been cited by experts when providing evidence about why a complainant may be mistaken about a relevant matter in a sexual violence case may well leave the reader with the impression that such scientific experimentation that has been done is rudimentary, flawed, and of negligible real relevance to such cases.

 

For example, on the topic of eyewitness identification and transference, the authors point out that research on mistakes made involving perpetrators who are strangers to the complainant is misleading or plainly wrong if applied to a case where the defendant is well known to the complainant. Similarly, in relation to studies on the “post-event (mis)information effect”, where in laboratory studies participants are deliberately given misinformation about what happened to see how that impacted on their subsequent accounts. These have a relevance problem: they mostly involve misinformation about minor, unimportant or subtle details, not the major details of a traumatic experience, or they involve observations of an event, not participation in it. They do not, and of course ethically cannot, concern sexual violence committed on the subject of study. Nor is there current scientific literature on the relevance of a sexual violence complainant’s confidence in giving evidence to the accuracy of that evidence, and the accuracy-confidence question is not settled science.

 

Similarly, false memory implantation studies are generally so artificial as to have minimal relevance to cases of sexual violence. They may be of relatively innocuous events, or carried out on university students, or use degrees of suggestion or social persuasion that have no relevance in the circumstances of a trial. And where there has been an ongoing relationship between the complainant and the defendant, there appears to be no research on how that might have affected complainants’ memories of abuse.

 

This is not to say that everything is necessarily uncertain. The authors summarise points on which a general consensus been established (with inevitable case by case exceptions) about children’s memory reports and suggestibility, including the danger of suggestive questioning, the loss of peripheral detail when there is delay, and the loss of detail of each episode when abuse has extended over a long period. Importantly, the authors offer guidance on how to evaluate experimental studies on children’s memories of sexual abuse, and stress the need for expert witnesses citing scientific studies to express the uncertainties of such evidence. Experimental research “does not and cannot represent the complexity and severity of sexual abuse.” (p 127)

 

Briefs of evidence that have been used in the cases surveyed here have tended to cover standard topics, even when not relevant to the case in which they are intended to be used, they tend to speculate on things such as post-event misinformation and transference, citing research but omitting to repeat reservations that the researchers may have expressed, such as the doubtful relevance of experimental studies to sexual abuse cases, or not declaring when their opinion does not have consensus within the literature.

 

The importance of recognising the body of knowledge available to clinical psychologists is also discussed by the authors. I imagine they would have more experience with genuine victims of sexual abuse and violence, rather than with liars, so they would not be ersatz lie detectors. Just potential myth-dispellers. The authors’ aim is to enhance complainants’ access to justice, and it is to be hoped that the defence, prosecution and judicial participants in court process will benefit from this valuable resource.

Monday, August 03, 2020

Evidence that might be wrong

I found it unsettling to read of scepticism about the prospects of success on an appeal referred to the Court of Appeal after consideration, by a retired judge, of fresh evidence.

As the matter is to be before the Court of Appeal again I say no more about that case. In fact, I know no more about it than anyone who has looked at newspapers or listened to news reports on the radio.

How should a fact-finder, a judge or a jury, deal with the evidence of a witness who might be mistaken?

Many kinds of testimony have an inherent risk of being wrong through mistake.

Should this evidence be assessed by comparison with other evidence on the same point and then be accepted or rejected before all the evidence is considered as a whole? Or, should assessment of the risk of error be suspended until all the evidence has been given and a verdict has to be decided on?

The difference is that suspension of decision on risk of error prevents the fact-finder from forming a theory about the result before all the evidence has been given. A premature theory can bias the assessment of other evidence.

It is unsafe to assess a case as strong before all the evidence in the trial has been given. Nevertheless, we expect a prosecution case to appear strong before a trial, for we do not want people to be prosecuted on weak evidence.

Juries are routinely told by judges that they must suspend judgment until after they have heard all the evidence, the addresses by counsel and the instructions on the law from the judge.

But, and here there is a risk of error, juries are also told that they must, in looking at all the evidence, decide what they accept and what they reject, and then decide whether the evidence they accept is sufficient to prove the prosecutor’s case beyond reasonable doubt.

This suggests a two-step approach to the evidence as a whole. First is the filtering out of evidence that, on an overview, the fact-finder rejects because it must be wrong. For example, evidence of a cast-iron alibi may mean that an eyewitness identification of the defendant at the scene must be wrong. The eyewitness evidence does not, in those circumstances, carry a possibility that it may be right. Second, considering all the remaining evidence, some may obviously be right, for example because there was no dispute about it, and some may most likely be right but with a smaller possibility that it is wrong. This sort of evidence is not taken on an all-or-nothing basis because the possibility of it being wrong is relevant to its probative value and to whether on the whole of the evidence there is a reasonable doubt about the defendant’s guilt.


I wouldn’t be as sceptical as the folk mentioned in the news report cited above. Judges are, in my experience of over 40 years of looking at them, fiercely independent-minded people. Any barrister who has struggled to get a judge to follow precedent will agree. Being trained as lawyers, they take pleasure in arguing, and they certainly don’t expect their opinions to be automatically accepted just because they are judges or retired judges. Their overriding concern is to make the law work rationally and justly.