The Supreme Court of Canada has simplified the direction that judges are to give juries on mixed statements. These are statements by an accused person that are partly incriminatory and partly exculpatory. Now, juries are not to be told that the exculpatory parts might be given less weight because the accused was not under oath when they were stated or because they were not subject to cross-examination: R v Rojas  SCC 56 (24 October 2008).
This is a rejection of the English approach to directing juries on mixed statements, which was established in R. v. Duncan (1981) 73 Cr. App. R. 359 and applied in R. v. Aziz  2 Cr. App. R. 478. Under this approach, it is proper for the judge to tell the jury that exculpatory parts of a mixed statement do not necessarily carry the same persuasive weight as incriminatory parts.
The cases suggest that an approach like that in Rojas has been approved in New Zealand: R v Tomkins  2 NZLR 170 (CA), R v Tozer  1 NZLR 193, (2001) 19 CRNZ 269 (CA), and – to pick an Australian example cited in Tozer – in Western Australia: Middleton v R (1998) 19 WAR 179 (CCA WA). Those cases support the proposition that it would be wrong to tell a jury that the exculpatory parts of a mixed statement may have less weight because they were not given under oath, the jury should be told to consider the whole of the statement and to give such weight to such portions of it as it thinks proper.
It has, however, been by no means unusual to hear judges suggest to juries that there are various circumstances that indicate that the exculpatory parts of mixed statements should be given little weight, while adding that these are matters for the jurors to decide for themselves. Indeed, judges could hardly sum up prosecution cases without referring to such circumstances. But the point is that under Rojas the weight differential is not a matter of law.
The wider context of all the circumstances of the case led the Court to conclude, in Rojas, that the misdirection was "more unfortunate than fatal" (41). This was particularly so because the judge had explained that a denial may raise a reasonable doubt as to guilt, that an accused was entitled to the benefit of the doubt, and the judge had left the assessment of the statements entirely to the jury.
On the other hand, in a case decided the same day, the misdirection on mixed statements was fatal: R v Illes  SCC 57 (24 October 2008). In contrast to Rojas, this was a majority decision. Here the jury may have thought that it was a matter of law that incriminating parts of mixed statements carry more weight than do exculpatory parts. The proviso could not be applied because the jury deliberations had been lengthy, the judge had given the misdirection after the jury had indicated they were at an impasse, and the mixed statements were critical evidence. The majority concluded that the jury would not inevitably have reached the same verdict if they had been properly directed.
Plainly, where the mixed statements do not form a critical part of the prosecution case, there will be significant evidence to suggest that their exculpatory parts deserve little weight; in such circumstances it would, as Illes illustrates, be harmless error for the jury to think that this reduced weight applied as a matter of law.
The common law rules as to how an accused's statements to the police should be treated in evidence developed as an exception to the rule against hearsay. As an exception, their contents were admissible as proof of their truth, and this was, over time, recognised as applying to the exculpatory parts as well as to the incriminatory parts. In New Zealand the relevant law has become statutory: Evidence Act 2006. This has not necessarily made the position simpler.
Section 27 provides that the hearsay rules do not apply to evidence offered by the prosecution in a criminal proceeding of a statement made by a defendant. It is not clear that the prosecution offers the exculpatory parts of a mixed statement, although the argument would be that these were offered as evidence of the defendant's lies. Section 124 provides for lies directions, but it will not always be the case that the defence would want this sort of direction given. Section 21 provides that if a defendant in a criminal proceeding does not give evidence he may not offer his own hearsay statement in evidence. Are the exculpatory parts of his mixed statement hearsay? Not if they are offered by the prosecution (s 27). If the prosecution omits reference to them, the defence may elicit them in cross-examination, and this amounts to "offering" them as evidence (s 4 definition of "offer evidence"), but because of s 21 the defence may only do this if the defendant is going to give evidence. Yet the defence may not have decided at that point whether the defendant will give evidence. Could the exculpatory parts of a mixed statement be admissible as ordinary hearsay evidence, under s 18, as s 18 is not subject to s 21? The problem with that is that there is a high reliability threshold for the admission of hearsay evidence, namely that the circumstances relating to the statement provide reasonable assurance that the statement is reliable: s 18(1)(a). Exculpatory statements are hardly likely to carry that assurance, otherwise the defendant would not be on trial.
I suspect that "a statement" in s 27 means the whole statement that was made, not just the incriminatory parts. Section 6(c) requires fairness, and the admissibility of exculpatory parts of mixed statements arose at common law out of considerations of fairness. Section 21 should be read restrictively, so that the exculpatory parts of the non-hearsay statement are offered not by the defendant but by the prosecution. There is no provision in the Act specifically addressing the nature of an appropriate direction that the jury should be given about the weight of exculpatory parts, but s 122 does permit the topic to be addressed and no particular form of words is required. The question whether to follow the Supreme Court of Canada's approach in Rojas will need to be decided, but it could be argued that s 122 pre-empts the courts' power to develop particular rules.