In the recent case of R v DAI, 2012 SCC 5 the Supreme Court tackled the issue of what test and standard is to be applied under section 16(3) - testimony on promise to tell the truth - in the context of sexual assault charges. The complainant in that matter was 22 years of age at the time she testified at trial, however, she had the mental age of a three to six year old. At trial her capacity to testify was challenged. After an inquiry the trial judge refused to permit her to testify. Ultimately, DAI was acquitted. The Crown appealed unsuccessfully to the Ontario Court of Appeal: 2010 ONCA 133. The Crown pursued an appeal to the Supreme Court.
McLachlin CJ wrote the majority ruling. She began her ruling with the following quotable quote:
Sexual assault is an evil. Too frequently, its victims are the vulnerable in our soceity - children and the mentally handicapped. Yet rules of evidence and criminal procedure, based on the norm of the average witness, may make it difficult for these victims to testify in courts of law. The challenge for the law is to permit the truth to be told, while protecting the right of the accused to a fair trial and guarding against wrongful conviction [para 1]; [emphasis added].
The issue raised in DAI was whether section 16(3) required, in addition to being able to communicate the evidence and promise to tell the truth, to understand what it means to tell the truth.
The trial judge favoured this interpretation and embarked upon questioning of the complainant to determine if the complainant understood. He concluded she did not [paras 84-90].
In undertaking her analysis, McLachlin CJ began by distinguishing between three different concepts: (i) competence; (ii) admissibility; and (iii) weight. The present appeal was concerned with the first of those concepts, competence. McLachlin CJ cautioned that courts need to be careful to consider these concepts separately and not permit admissibility or weight concerns to filter into a consideration of competence.
With respect to section 16(3) McLachlin CJ noted that the section is clear on its face and rejected the respondent's assertion that the plain words of the section do not suffice [paras 20-53]. Those plain words establish that there are only two requirements of section 16(3).
First, that the witness be able to communicate the evidence.
Second, that the witness promise to tell the truth.
In rejecting the assertion that something more should be read into the section, McLachlin CJ offered the following points.
First, there is no ambiguity in the words of the section and therefore it would be improper to read more into the section [para 26].
Second, the history of the section shows that Parliament intended to "eliminate an understanding of the abstract nature of the oath or solemn affirmation as a prerequisite for testimonial capacity" [paras 27-30].
Third, the "internal logic" of the section negates the assertion that an understanding of telling the truth must be analyzed by the court [para 31].
Fourth, "s. 16(4) indicates that ability to communicate the evidence is the only quality that an adult with mental disabilities must possess in order to tesitfy under s. 16(3)" [para 32].
Fifth, the legislative context further supports that only the two requirements noted are to be read from section 16(3) [para 33].
McLachlin CJ further considered the relevant jurisprudence [paras 54-63] and policy considerations [paras 64-73] and concluded they both support the same interpretation.
In conclusion McLachlin CJ noted that there are two "conditions for testimonial competence": first, the witness must be able to communicate the evidence; second, the witness must promise to tell the truth [para 74].
In terms of applying section 16(3) in the context of section 16, McLachlin CJ offered the following observations.
First, the voir dire on competence is an independent inquiry [para 76].
Second, the court should hear all relevant evidence before making a ruling [para 77].
Third, the primary source of information should be the witness themselves [para 78].
Fourth, those who support and know the witness can testify as "fact witnesses to provide evidence on her development" [para 79].
Fifth, expert evidence may be admitted but it generally is best if the expert had contact with the witness [para 80].
Sixth, the court should consider (a) does the proposed witness understand the nature of an oath or affirmation, and (b) can she communicate the evidence [para 81].
Seventh, the second inquiry requires the judge to "explore in a general way whether she can relate concrete events by undertsanding and responding to questions" [para 82].
Eighth, if the witness only passes the second part she can testify on promise to tell the truth [para 83].