Secondary Materiality and Your Own Witness

• Author: David M. Paciocco/Lee Stuesser
• Pages: 442-474

1. THE BAR ON BOLSTERING THE

CREDIBILITY OF YOUR OWN WITNESS

As a general rule, a party may not ask questions or present evi-

dence solely to bolster the credibility of his own witness.

Although it may be of assistance to hear testimony about the value of the

evidence that has been led in a case, there is concern that to allow this

would take an undue amount of time and create distracting side issues.

Until their credibility has been made an issue by the opposing party, wit-

nesses are assumed to be trustworthy and of good character.1As a gen-

eral rule, therefore, a party cannot initiate evidence solely to establish

that his witnesses are credible. Evidence must be about the primarily

material issues in the case, not about other evidence in the case. In R. v.

Siu this rule was contravened where a police officer stated that he

believed the key Crown witness. The rule was further breached when the

officer testified that his belief was based in part on the offer of the Crown

witness to take a polygraph test. Where a party leads inadmissible evi-

dence to support the credibility of one of its witnesses in a jury trial, the

trial judge should immediately direct the jury to disregard the evidence.2

442

1R. v. Giraldi (1975), 28 C.C.C. (2d) 248 (B.C.C.A.), leave to appeal refused

(1975), 28 C.C.C. (2d) 248n (S.C.C.).

2 (1998), 124 C.C.C. (3d) 301 (B.C.C.A.).

SECONDARY

MATERIALITY AND

YOUR OWN WITNESS

chapter 11

Secondary Materiality and Your Own Witness 443

At the same time, it is permissible and indeed customary to intro-

duce a witness to the court. It is common to see witnesses provide their

age and describe their family and employment status and their connec-

tion to the case. Frequently, counsel will attempt to introduce his wit-

nesses in a way that will enhance the witness’s credibility. It is a question

of degree when the line is crossed between permissible introduction and

impermissible “bolstering.” In R. v. Clarke, for example, that line was

crossed when a police informant testified that he was allowed to leave

the prison for street visits, he was studying the Bible, he attended Alco-

holics Anonymous, and he had reformed his criminal ways.3

2. GOOD CHARACTER EVIDENCE: THE

ACCUSED AS A WITNESS

By way of exception, as an indulgence to the accused in a criminal case,

the accused can prove his good character in a variety of ways. Such evi-

dence is considered relevant both to the primarily material issue of

whether the accused committed the offence charged and to the sec-

ondarily material issue of the credibility of the accused as a witness.4

The methods for presenting such evidence on the issue of credibility

are identical to those available where the good character evidence is

being offered to cast doubt on the guilt of the accused.5In particular,

the testifying accused can assert his own honesty, and other witnesses

can be called to testify as to the reputation of the accused for truthful-

ness and veracity.6If the accused chooses to put his character in issue

in either of these ways, the Crown will be entitled to rebut the claim to

good character by cross-examining the accused or character witness, or

by calling other witnesses who will testify to the accused’s bad reputa-

tion for trustworthiness or sincerity.

3 (1981), 63 C.C.C. (2d) 224 (Alta. C.A.).

4R. v. H.(C.W.) (1991), 68 C.C.C. (3d) 146 (B.C.C.A.).

5 See Chapter 3, section 13, “Good Character Evidence and Modes of Presentation.”

6R. v. Clarke (1998), 18 C.R. (5th) 219 (Ont. C.A.).

444 The law of Evidence

3. Secondarily Material Expert

Evidence

A party may call an expert witness to testify about facts relevant

to the credibility of one of his witnesses where those facts are like-

ly to be beyond the experience of the trier of fact. The rule against

oath-helping prevents the expert from going so far as to testify that

the witness is likely to be telling the truth.

In R. v. Kyselka,7the Ontario Court of Appeal held that it was impermis-

sible for a medical doctor to explain that a mentally challenged sexual

assault complainant lacked the imagination and intelligence to concoct

the story she had told. The Court said this was analogous to the pre-Nor-

man practice of “oath-helping,” by which a party would call persons who

knew nothing of the event, but who would swear that this party’s oath

was true. Similar reasoning was employed by the Supreme Court of Cana-

da in R. v. Béland8to reject the admission of the evidence of a polygraphist

who would have testified that the accused passed a lie detector test.

Recently, courts have taken a more generous view. In some cases,

factors relevant to the credibility of a witness are beyond the ordinary

experience and understanding of lay triers of fact. Without the assis-

tance of experts, lay triers of fact are apt to make erroneous assump-

tions about credibility. For example, lay persons may not appreciate

that children cannot be expected to notice time and place the way that

adults do, or that sexually abused children are prone to fantasize or to

retract their allegations.9Or they may not appreciate that the professed

inability to recall can be the result of hysterical amnesia.10 Where com-

mon experience does not provide the tools needed to assess the credi-

bility of a witness, a party will be entitled to call an expert to provide

that information, even though the testimony of the expert does noth-

ing more than support the credibility of another witness.

This practice is not without its limits. The modern rule against

oath-helping prevents expert witnesses from offering the opinion that

a particular witness is telling the truth. The expert can provide back-

ground information relevant to the credibility of a witness, but not

information directly about the credibility of what a witness is saying.11

7 (1962), 37 C.R. 391 (Ont. C.A.).

8(Sub nom. Béland v. R.) (1987), 60 C.R. (3d) 1 (S.C.C.).

9 See, for example, R. v. J.(F.E.) (1990), 74 C.R. (3d) 296 (Ont. C.A.).

10 R. v. Clark (1983), 35 C.R. (2d) 357 (Ont. C.A.).

11 See generally, chapter 6, section 3.3, “The Rule against Oath-Helping.”