The application of the collateral evidence rule can vary depending on case and judge. Obviously circumstances will yield different outcomes. For example, here is a case from Ontario, Canada, pertaining to evidence introduced by the defence. [Emphasis mine.]
R. v. Deschamps; 1994; ON General Division
Application of the Collateral Evidence Rule
4 In a nutshell, the defence argues that the evidence he wishes to call does not go to a collateral matter, but to the issue of the complainant's propensity to fabricate evidence of abuse by the accused. He contends that because the complainant made similar allegations against the same man, in the same statement, regarding events in their continuous relationship, questions going to the issue of fabrication are not on a collateral matter. Simply put, he wants to call evidence to prove that the complainant lied in the statement as to one significant fact, namely an injury or injuries resulting from one assault by the accused, and therefore probably lied as to other facts including the details of the series of incidents themselves.
5 At first blush the argument is appealing. Upon consideration of the case law, however, there does not appear to be any authority which would allow me to characterize the proposed evidence as anything other than an impermissible contradiction on a collateral issue as to credibility. In addition, the rationale behind the "collateral evidence rule" - namely to prevent rebuttal evidence which is largely irrelevant, and expands the inquiry beyond the charge before court - is in my view applicable to the case at bar despite the similarities of the allegations.
6 I will first briefly review the cases relied upon by the Crown, and then attempt to distinguish the most important of those relied upon by the defence.
7 In the 1992 decision of R. v. Riley 11 O.R. (3d) 151, the Ontario Court of Appeal applied the traditional rule to a case of sexual assault in which the defence proposed to show that the complainant had fabricated an allegation of sexual assault against another man. Specifically, he cross-examined her concerning the allegations, then proposed to call the man to testify that he was charged and acquitted. The Court stated at pp. 154 - 155:
"The only legal basis of which we are aware that would justify the cross-examination of this complainant along the lines suggested would be in order to lay the foundation for a pattern of fabrication by the complainant of similar allegations of sexual assault against other men. This should not be encouraged unless the defence is in a position to establish that the complainant has recanted her earlier accusations or that they are demonstrably false ... The problem of proving falsity in these circumstances is considerable. To have Roswell testify that her complaint to the authorities about him was false, would only introduce a collateral issue of credibility which would be as difficult to resolve as those contained in the complaints of which the trial judge was seized. We agree with counsel for the Crown that this cross-examination was on a collateral matter in that it was essentially an attack on the general character of the complainant".
8 In a somewhat similar decision, R. v. Rattan, 68 C.R. (3d) 84, the British Columbia Court of Appeal prevented an accused charged with sexual assault from calling evidence which allegedly would have shown a propensity on the part of the complainant to make false allegations of sexual assault against men of East Indian race. The court ruled that the contradictory evidence can only be called if it is directed to an earlier answer which is relevant to an issue in the case:
"However, it does not matter whether the question of categorization is directed to the earlier evidence or the new evidence. If the new evidence goes to general credibility alone, it should not be permitted, but if it goes to the credibility of specific earlier testimony on a matter relevant to an issue in the case, it should not be rejected as being collateral".
9 The Court goes on to consider, and reject an argument that the previous incident was markedly similar, and thus capable of showing a true propensity to fabricate. Similarly, in Riley the court determined that a foundation had not been laid for allegations of a "pattern of fabrication" by the complainant. In another decision involving alleged fabrications of prior assaults, R. v. B.A.W., 59 O.A.C. 323, the Supreme Court of Canada rejected evidence of the alleged fabrication on the ground that prejudice far outweighed relevance.
10 In comparing the argument before me regarding propensity to fabricate to those put forward in the above cases, I find that the proposed evidence is even less probative of credibility regarding the issue before the court. In each of those cases, the proposed testimony dealt with allegations of prior assaults, albeit by other men; in the case at bar, the evidence merely addresses the question of the extent of observable injuries caused in a prior assault. In other words, the collateral matter, the degree of prior injury, is even less relevant to the issue of whether the May 1993 assault took place than the collateral issue of fabrication of prior assaults was to the charges before the courts in those cases. The defence assertion that he has confirmed that the doctor will deny seeing teeth or choke marks does not make her observations any more probative of a propensity to fabricate allegations of assault.
11 Defence relied strongly on the case of R. v. Gonzague, 4 C.C.C. (3d) 505, (Ont. C.A.) in which the court allowed cross-examination of a Crown witness on outstanding fraud charges. The court applied the normal rule, allowing the cross-examination on unrelated matters going to general credibility, but in no way dealt with an attempt to call rebuttal evidence. He also placed strong reliance on R. v. Krause 29 C.C.C. (3d) 385 (S.C.C.), wherein the accused alleged police harassment, and the Crown attempted to call rebuttal evidence. In a judgment which in my view supports the position of the Crown in this case, the court refused the request, on the grounds that the matter was collateral and irrelevant to the issues in the case itself.
12 The cases of R. v. P.N.P. 81 C.C.C. 3d 525 (Nfld. C.A.) and R. v. Speid 42 C.C.C. (3d) 12 (Ont. C.A.), similarly relied upon, deal in my view with evidence going to the issues of oblique motive and bias of a witness, rather than mere contradiction on a collateral matter.
13 As I stated initially, not only the case law, but also the rationale behind the collateral evidence rule supports exclusion of the doctor's evidence. Hypothetically, the denial of observation of teeth marks by one doctor could prompt the Crown to seek to adduce evidence of contrary observations by others or even expert evidence on the duration of such marks; in other words, the inquiry on a collateral issue could expand and become increasingly irrelevant. While the doctor will apparently deny the existence of choke marks, the complainant herself did not insist that the alleged choking left marks; it therefore seems likely that the related questions will have to go beyond mere observations into the likelihood of marks occurring in order to be of any value.
14 Despite the initial appeal and creativity of the defence submission, it must fail as it is not supported by jurisprudence or the rationale of the traditional rule. The issue of the existence or extent of certain injuries is no more than a collateral matter going to general credibility, and counsel is left with the answers he got in cross-examination. The doctor will not be called.