Thursday, May 19, 2011

Counter-intuitive evidence: should neutrality be sought?

Correction of wrong intuitions is important to prevent jury bias. Commonly held assumptions about the way a complainant should behave may unfairly affect the jury's assessment of that person's credibility.

Delay in complaining, or the continuation of a relationship between the complainant and the defendant, might be thought to undermine the credibility of the complainant. They may indeed undermine credibility on the facts of a particular case, but it would be wrong for the jury to apply a rule of thumb when assessing the evidence.

In M (CA23/2009) v R [2011] NZCA 191 (18 May 2011) the New Zealand Court of Appeal considered ways of countering the wrong intuitions that jurors may have about the significance of such circumstances to credibility. It referred in particular to decisions of the Supreme Court of Canada, R v DD 2000 SCC 43, [2000] 2 SCR 275, and the Court of Appeal of England and Wales, R v Miller [2010] EWCA Crim 1578. Expert witnesses may give evidence on the counter-intuitive significance of such circumstances, the judge may direct the jury on the dangers of making assumptions, or counsel may agree on a statement to the jury on the point.

Those techniques of countering wrong intuitions are aimed, said the Court in M(CA23/2009) at [25], adopting a comment by the New Zealand Law Commission, at restoring a complainant's credibility from a debit balance because of jury misapprehension, back to a zero or neutral balance. It needs to be added that the defendant should also be allowed to use these techniques to prevent wrong intuitions being used against him.

We might wonder whether the aim of setting the credibility balance back to neutral is necessarily correct. Some kinds of behaviour may well indicate reliability in general. Not everything is neutral. Delay may be neutral, but a quick complaint may in the generality of cases indicate reliability. The continuation of an apparently good relationship between the complainant and the defendant may be neutral, but a sudden breakdown of a relationship may in general indicate that the complaint is true. Or in turn those intuitions may prove to be false. What do the scientific studies show?

There is no reference in M(CA23/2009) to statistical data on the significance of types of behaviour to the truth or falsity of complaints. But at least we can say that logically it is necessary to compare the occurrence of the behaviour in the cases of true complaints, to its occurrence in the cases of false complaints.

The jury must not be left in the impossible position of having to use their collective common sense while at the same time treating as neutral behaviour that may well be useful in assessing credibility. How can a jury decide the significance of such behaviour in the particular case without putting it in a more general context?