Rape shield laws Canada

 R. v. M.T., 2012 ONCA 511 has a helpful summary of the rules regarding the exclusion of evidence of sexual conduct in sexual offenses:

[29]       Section 276 of the Criminal Code creates a statutory rule of admissibility.  Enacted in negative terms, the section, like other admissibility rules, is exclusionary; it precludes the admission of certain evidence. The exclusionary effect of the rule only becomes engaged when three requirements have been met. For discussion purposes, these requirements, which are cumulative, may be characterized as:

i.             offence charged;

ii.            subject-matter; and

iii.           purpose.

The exclusionary rule prohibits the person charged from introducing certain evidence (subject-matter) for a specific use (purpose) in proceedings for a listed crime (offence).

[30]       The "offence" requirement is satisfied where the proceedings in which evidence is tendered relate to a listed offence.  Among the listed offences are the crimes charged here: sexual assault, sexual interference, and invitation to sexual touching.

[31]       The "subject-matter" requirement, which appears in both sections 276(1) and (2), is best expressed in the language of subsection (2):

Evidence … that the complainant has engaged in sexual activity other than the sexual activity that forms the subject-matter of the charge, whether with the accused or with any other person.

If the subject-matter of the proposed evidence falls outside the statutory language, the exclusionary terms of the provision do not apply.  On the other hand, satisfaction of the subject-matter requirement, on its own, will not necessitate exclusion; the "purpose" requirement must also be satisfied.

[32]       The "purpose" requirement is crucial to the operation of this exclusionary rule, just as it is with the common law hearsay rule. To engage the exclusionary rule of s. 276, the proposed evidence must be offered to support either of two prohibited inferences grounded on the sexual nature of the activity:

i.             that the complainant is more likely to have consented to the conduct charged; or

ii.            that the complainant is less worthy of belief.

Where the purpose underlying the introduction of the evidence of extrinsic sexual activity is neither of those prohibited by s. 276(1), this exclusionary rule is not engaged.

[33]       Section 276(2) provides an exception to the exclusionary rule. To gain entry under this exception, evidence of the complainant's extrinsic sexual activity must:

i.             be of specific instances of sexual activity;

ii.            be relevant to an issue at trial; and

iii.           have significant probative value that is not substantially outweighed by the danger of prejudice to the proper administration of justice.

To determine whether the evidence should be admitted under this exception, the presiding judge must follow the procedure described in ss. 276.1 and 276.2 and consider the factors listed in s. 276(3).

[34]       The admissibility rules of s. 276 apply only where the evidence proposed for admission is of extrinsic sexual activity on the part of the complainant. A previous allegation of assault, without more, would fall outside the section: R. v. Gervais(1990), 58 C.C.C. (3d) 141 (Que. C.A.), at p. 154. Questions that focus on the fact, rather than the details, of an allegation of sexual assault are not prohibited by the section: R. v. M. (A.G.) (1993), 26 C.R. (4th) 379 (Que. C.A.), at p. 393.