Is Other Sexual Activity Evidence Admissible?

The Twin Myths Rule and the Architecture of Consent Under Canadian Criminal Law

Criminal Code ss. 276–278 · Sexual Assault Evidence · Evidentiary Doctrine

In the architecture of Canadian evidence law, few doctrines are so firmly entrenched and so frequently misunderstood as the twin myths rule. Enshrined in section 276 of the Criminal Code, the prohibition targets two ancient and empirically discredited inferences about complainants in sexual assault proceedings — the idea that other sexual activity evidence makes a complainant more likely to have consented on the occasion in question, and the companion notion that such evidence makes her a less credible witness. Together, these propositions are what Parliament, and the Supreme Court of Canada have called the “twin myths,” and their exclusion from the reasoning of judge and jury alike stands as one of the most deliberate interventions in Canadian evidentiary doctrine.

Understanding why these inferences were targeted, how the exclusionary rule operates in practice, and where courts have had to draw difficult lines between legitimate evidence and mythological reasoning is indispensable for anyone engaging with contemporary Canadian criminal law around sexual violence.

PART I

Origins: What Are the Twin Myths?

The term “twin myths” entered Canadian legal vocabulary through the Supreme Court’s landmark 1991 decision in R v Seaboyer, where Justice McLachlin (as she then was) articulated with precision the two flawed inferences that had plagued sexual assault trials for generations. Writing for the majority on the constitutional question, she identified them as follows.

Neither inference has any rational evidentiary basis. Neither corresponds to the way human beings actually behave. And yet both had been embedded in the common law for centuries, drawn from a tradition — most famously articulated by the seventeenth-century English jurist Sir Matthew Hale — that treated the unchaste woman as presumptively dishonest and presumptively available.

“The use of sexual history evidence to support the two forbidden inferences is more prejudicial than probative. It rests on stereotype; it demeans the victim; and it may unduly deflect the jury from the real issues in the case.”

R V SEABOYER, [1991] 2 SCR 577, MCLACHLIN J.

These myths were not merely theoretically problematic. Empirical research, sociological evidence, and the hard experience of complainants in courtrooms across Canada demonstrated that cross-examination on sexual history was a powerful tool for humiliation rather than truth-finding. The legal system, by permitting such inquiry, had become complicit in the harassment of those it was meant to protect.

PART II — SS. 276, 276.1 & 276.2

The Statutory Framework: Section 276 of the Criminal Code

Parliament’s response to Seaboyer — which had struck down the predecessor provision as unconstitutionally overbroad — was the amended section 276, which has been described as a carefully calibrated balance between the complainant’s privacy and dignity interests and the accused’s right to make full answer and defence.

The provision is not an absolute ban on all other sexual activity evidence. Section 276(2) allows such evidence to be admitted when three conjunctive conditions are met: the evidence must relate to specific instances of sexual activity; it must be relevant to an issue at trial; and its probative value must not be substantially outweighed by the danger of prejudice to the proper administration of justice.

The Gatekeeper Hearing

When an accused seeks to lead other sexual activity evidence, section 276 requires an application to be made to the trial judge at a voir dire — a hearing held in the absence of the jury or the public where the admissibility question is resolved. The procedure serves multiple purposes: it prevents a jury from being exposed to evidence that may ultimately be excluded; it gives the complainant standing to participate in the admissibility determination; it prevents improper questions and evidence from becoming part of the trial record and it creates a formal record that appellate courts can review.

This hearing is an important structural protection. It recognizes that the mere asking of certain questions — quite apart from the answers — can have a profound effect on how a jury perceives a complainant. By requiring advance judicial screening, the Code attempts to prevent prejudice that cannot be undone by a subsequent instruction.

PART III

The Constitutional Journey: Seaboyer to Darrach

The current legislative framework emerged through a constitutional dialogue that is itself instructive about the competing values at stake. Understanding the jurisprudential history is essential for grasping why the present law is framed as it is.

1983

Bill C-127 — The First Rape Shield

Parliament’s initial attempt at restriction. Evidence of prior sexual history with anyone other than the accused was made categorically inadmissible. Evidence of prior sexual activity with the accused was limited to recent acts. The provision was broadly praised but ultimately found to be constitutionally infirm.

1991

R v Seaboyer, [1991] 2 SCR 577

The Supreme Court strikes down the 1983 provision by a 7-2 majority. The majority reasons that a blanket exclusion could prevent an accused from adducing evidence necessary to make full answer and defence. Justice McLachlin identifies three categories of evidence the prior rule would wrongly exclude. The dissent by L’Heureux-Dubé J. becomes foundational, emphasizing the perpetuating harm of the myths.

1992

Bill C-49 — The Current Section 276

Parliament responds with a new framework: a qualified exclusionary rule, a formal admissibility hearing process, and the codification of the twin myths prohibition. The new provision explicitly incorporates several of the principles articulated in Seaboyer.

2000

R v Darrach, [2000] 2 SCR 443

The Supreme Court unanimously upholds the constitutionality of the revised section 276 regime. Justice Gonthier holds that the provision does not violate ss. 7 or 11(d) of the Charter. The decision confirms that the right to make full answer and defence does not include the right to use constitutionally impermissible forms of evidence.

2022

R.v. J.J., 2022 SCC 28

The Supreme Court finds that new legislation passed by Parliament in 2018 is constitutional. The new legislation, adding s. 278.92, requires the defence to bring a pre-trial application related to any evidence in their possession for an assessment of the complainant’s privacy interest, weighing the probative value against prejudicial effects. This new screening process applies to all defence evidence whether of a sexual nature or not. It additionally expands prior sexual history to any evidence of a “sexual nature.” The defence is required to bring an application in all circumstances, out of an abundance of caution, to avoid trial delays.

PART IV — SS. 276(2) & 273.2

What the Rule Permits: The Legitimate Uses of Other Sexual Activity Evidence

The twin myths rule is often mischaracterized as a total prohibition. It is not. What it prohibits is a specific type of inference — reasoning from other sexual activity evidence to consent or credibility through the lens of myth and stereotype. Other sexual activity evidence may be admissible for a variety of other purposes, provided it clears the section 276(2) threshold.

KEY AUTHORITY

R v Seaboyer — The Three Legitimate Categories

Justice McLachlin’s majority in Seaboyer identified three types of evidence the former rule would wrongly exclude: evidence of recent false complaints by the complainant; evidence of prior sexual activity that might explain physical evidence such as semen or injury; and evidence of prior sexual activity with the accused relevant to the accused’s honest belief in consent. These categories inform, but do not exhaust, the legitimate uses of such evidence under the current regime.

Other sexual activity evidence between the accused and the complainant may be relevant to the accused’s defence of honest but mistaken belief in consent — now codified as requiring that the accused take reasonable steps to ascertain consent (s. 273.2). The probative value of such evidence, however, must be carefully isolated from the forbidden inferences.

Physical evidence — evidence that other sexual activity explains an injury, or that a pattern of other activity is inconsistent with the physical findings — may be admissible where it is genuinely probative on a point other than consent or credibility by stereotype. The key analytical question, as the Court in Darrach made clear, is always whether the evidence is being led to establish the truth of an issue at trial through legitimate reasoning, or whether it is being used as a backdoor to the twin myths.

The Problem of Disguised Myth Reasoning

Some of the most difficult cases involve evidence that appears on its face to be relevant to a legitimate issue but is in fact offered to smuggle mythological reasoning into the fact-finding process. Defence counsel may frame an argument in terms of contextual background or relationship history while the actual inference sought from the jury is precisely the kind of stereotype-based reasoning section 276 is designed to prevent.

Courts have responded to this challenge by scrutinizing the chain of reasoning from the proposed evidence to the desired conclusion, rather than accepting characterizations at face value. The question is not whether the evidence is dressed up in permissible language, but whether the probative pathway to admissibility improperly runs through the twin myths or around them.

PART V — S. 277

Section 277: Reputation Evidence and the Companion Prohibition

Section 276 is accompanied by section 277, which provides that evidence of sexual reputation — in contrast to specific instances of sexual activity — is inadmissible in any proceeding to impugn or support the credibility of the complainant. The two provisions work in tandem: section 276 addresses specific instances; section 277 forecloses the even more speculative and prejudicial avenue of general reputation evidence.

The rationale for section 277 is straightforward: reputation evidence about sexual conduct is inherently more inflammatory, less reliable, and more directly grounded in mythological reasoning than even specific instances. If specific instances are presumptively excluded absent a compelling reason, reputation evidence — which rests on generalizations built upon generalizations — enjoys no possible claim to admissibility.

PART VI — S. 273.2

Honest Belief in Consent: The Intersection with the Twin Myths

The defence of honest but mistaken belief in communicated consent creates one of the most fraught intersections in this area of law. An accused who claims a genuine belief that the complainant consented may wish to lead other sexual activity evidence as relevant to the reasonableness and genuineness of that belief. This creates an apparent tension with the twin myths prohibition.

The resolution, developed through cases like R v Ewanchuk and refined in subsequent jurisprudence, rests on a crucial distinction. Other sexual activity evidence may be relevant to the accused’s state of mind — what the accused actually believed, and whether that belief was reasonable in the circumstances — without supporting the inference that the complainant was more likely to have consented. The relevance pathway must run through the accused’s subjective mental state and the objective reasonableness of that state, not through a generalization about the complainant’s likely behaviour.

“The accused’s perception of the circumstances cannot be assessed in isolation. Context matters. But context is not a licence to reason from past behaviour to present consent through the back door of myth and stereotype.”

COMMENTARY ON R V EWANCHUK, [1999] 1 SCR 330

This distinction is easier to state than to apply. In practice, the line between evidence going to the accused’s belief and evidence supporting a mythological inference about the complainant is often contested, and trial judges must exercise careful analytical attention to ensure that the formal admissibility of evidence on the belief issue is not converted into an invitation for the jury to engage in twin myths reasoning under another name.

PART VII — S. 276

Digital Evidence and New Frontiers

The advent of digital communication has generated a new set of challenges for the twin myths framework. Electronic messages — texts, emails, social media posts, dating app conversations — increasingly feature in sexual assault proceedings, and the question of whether and when such evidence is governed by section 276 has required careful judicial attention.

Courts have grappled with whether a sexually-explicit text message between an accused and a complainant constitutes evidence of “sexual activity” within the meaning of section 276. The answer depends on the nature and content of the communication. A message that constitutes or describes or invites sexual activity will typically engage the provision; a message that establishes a prior relationship or social context without explicit sexual content may not.

The intersection of digital evidence and the twin myths analysis is not merely procedural. It raises deeper questions about how the values animating section 276 — respect for complainant autonomy, rejection of stereotyped reasoning, protection of privacy — apply in an age where intimate communications are more voluminous, more preserved, and more routinely disclosed than at any prior point in legal history.

PART VIII — SS. 276 & 278.1

Records in the Possession of the Accused: The Regime Under Sections 276 and 278

A distinct but closely related area of law governs what happens when the accused is in possession of private records relating to the complainant — records that may be relevant to the defence but that also engage the complainant’s privacy and dignity interests. This regime has become increasingly significant as private communications, personal journals, medical and therapeutic records, and intimate images feature more frequently in sexual assault proceedings.

The intersection of section 276 and the third-party records framework under sections 278.1 to 278.91 raises a specific and practically important question: what procedures govern the admissibility and use of a private record that is already in the accused’s hands, rather than in the hands of a third party whose production must be compelled through the courts?

The Threshold Question: What Is a “Record”?

Section 278.1 of the Criminal Code defines “record” broadly to include any form of record that contains personal information for which there is a reasonable expectation of privacy. The definition explicitly includes medical, psychiatric, therapeutic, counselling, educational, employment, child welfare, adoption, and social services records, as well as personal journals and diaries, and records containing personal communications. The breadth of this definition is intentional: Parliament recognized that the categories of documentation that may be weaponized in sexual assault proceedings are not static.

The definition excludes records made by those investigating or prosecuting the offence — that is, Crown disclosure and investigative materials — which are governed by the ordinary disclosure regime under R v Stinchcombe. Everything else that might be described as a private record of or about the complainant falls within the protective framework.

Records in the Accused’s Possession: A Gap in the Original Framework

The original sections in the 278 regime were designed primarily to address applications by the accused to compel production of records held by third parties — counsellors, therapists, hospitals, schools. The question of what happens when the accused is already in possession of a record did not receive explicit legislative treatment in the original scheme, and early cases revealed an arguable lacuna in the law.

The issue crystallized in cases where an accused had by some means obtained records that fell within the section 278.1 definition: text message exchanges, photographs, diary entries shared in confidence, or medical information disclosed in a personal context. Defence counsel took the position that because these records were already in the accused’s hands, the third-party records regime did not apply — the accused was not seeking compelled production from anyone, and the ordinary rules of admissibility governed.

The practical effect of J.J. is that an accused who seeks to introduce at trial a record meeting the section 278.1 definition must satisfy the court that the material clears a threshold of likely relevance, and the court must then weigh the competing interests of complainant privacy against the accused’s right to make full answer and defence — the same balancing exercise that governs third-party production applications, adapted to the context where no compelled disclosure is required.

The Two-Stage Admissibility Analysis

Where the accused seeks to introduce a record in their possession, courts now apply a two-stage analysis that mirrors, with necessary modifications, the procedure applicable to third-party records applications. At the first stage, the accused must establish that the record is likely relevant — that there is a reasonable possibility it will assist in making full answer and defence or that its exclusion would be prejudicial to the right to a fair trial. This threshold is deliberately set low enough to prevent the process from becoming a determination of ultimate admissibility on insufficient information.

If the first-stage threshold is met, the trial judge proceeds to the second stage: a balancing of the complainant’s privacy interest against the accused’s interest in full and fair disclosure. The Code sets out a non-exhaustive list of factors to be weighed, including the extent to which the record is necessary to enable the accused to make full answer and defence, the probative value of the record, the nature and extent of the reasonable expectation of privacy in the record, and the potential prejudice to the complainant’s dignity, privacy, and security.

Intersection with Section 276: The Double-Gatekeeper Problem

A record in the accused’s possession may simultaneously engage both the section 278 regime — because it constitutes a private record within the statutory definition — and the section 276 regime — because the record contains sexual content or has connection to other sexual activity involving the complainant. In such cases, both sets of procedural protections apply, and the accused must satisfy both gatekeeping regimes before the evidence can be placed before the trier of fact.

This double-gatekeeper structure reflects the recognition that the harms animating each regime are distinct but cumulative. Section 276 addresses the risk of mythological reasoning from other sexual activity evidence; section 278 addresses the risk of privacy violation through disclosure or production of intimate personal information. A sexually explicit text message sent between the accused and the complainant engages both concerns simultaneously: its admission may invite twin myths reasoning, and its disclosure may violate the complainant’s reasonable expectation of privacy in that communication.

Complainants have privacy interests in highly sensitive information about themselves, the disclosure of which can impact on their dignity. As this Court has observed in the past, the “dissemination of highly sensitive personal information” can result “not just in discomfort or embarrassment, but in an affront to the affected person’s dignity” (Sherman Estate v. Donovan, 2021 SCC 25, [2021] 2 S.C.R. 75, at para. 7). To reach the level of an impact on dignity, an intrusion on informational privacy must “transcen[d] personal inconvenience by reason of the highly sensitive nature of the information that might be revealed” (Sherman Estate, at para. 75; see also para. 73).

R.v. J.J., 2022 SCC 28

The practical consequence for defence counsel is that the admissibility of a record already in the accused’s possession may be significantly more constrained than the mere fact of possession would suggest. Counsel must engage with both regimes at the planning stage and must anticipate applications that address section 276 and section 278 simultaneously, particularly where the record involves intimate communications or depicts sexual activity.

Practical Implications for Defence and Crown

For defence counsel, the new regime governing records in the accused’s possession creates a series of procedural obligations that must be addressed proactively. Counsel should identify at the earliest stage of file review whether any material in the accused’s possession falls within the definition of a “record” with an expectation of privacy. Where it does, counsel should conduct the likely-relevance analysis and, if a threshold argument is sustainable, prepare the record review application with precision — identifying the specific purpose for which the record will be used and the legitimate defence interest it is said to serve.

For the Crown, the regime creates an obligation to be alert to defence reliance on private records and to intervene appropriately where a proper application has not been brought. Failure to object at trial to the admission of a record without the required procedure may complicate appellate review, though courts have been willing to consider the issue on appeal where the procedural deficiency was sufficiently serious to affect the fairness of the proceeding.

The regime under sections 276 and 278 for records in the possession of the accused thus represents one of the most procedurally complex areas of Canadian sexual assault law. It requires defence counsel to navigate overlapping statutory frameworks, to anticipate the complainant’s participation as a quasi-party to admissibility proceedings, and to articulate with precision the legitimate defence use of sensitive material — all while the accused’s right to make full answer and defence remains the animating constitutional value against which the procedural constraints must be measured.

PART IX

Judicial Instruction and the Risk of Residual Mythological Reasoning

Even where other sexual activity evidence is properly admitted for a legitimate purpose, the risk that the jury will deploy it for the prohibited purposes remains. Judicial instructions — sometimes called “limiting instructions” or “use instructions” — are the primary tool for managing this risk.

A proper direction on the twin myths requires more than a formulaic recitation. The trial judge must explain in plain language what the prohibited inferences are, why they are prohibited, how the admitted evidence may and may not be used, and how the jury is to compartmentalize different uses of the same material. Given what social science research tells us about the difficulty of jury instruction compliance, the demand placed on this tool is substantial.

The Supreme Court has held that the failure to deliver an adequate limiting instruction where one is required constitutes a reversible error. At the same time, courts have recognized that an instruction that is overly long or complex may itself confuse rather than clarify. The craft lies in communicating the essential prohibition — do not use this person’s past to judge their credibility or assume their consent — in terms that a lay jury can understand and apply.

CONCLUSION

The Ongoing Work of Dismantling Myth

The twin myths rule represents one of Canadian criminal law’s most deliberate and sustained engagements with the relationship between legal doctrine and social harm. It recognizes that evidence law is not neutral — that the rules that determine what a jury may see and use in their reasoning shape the experience of trial in ways that can either perpetuate or dismantle systemic injustice.

The legislative and judicial architecture around section 276 is sophisticated. It does not silence the accused. It does not categorically exclude relevant evidence. What it does — and what it insists upon — is that evidence must earn admission through legitimate reasoning rather than through the shortcut of stereotype. A prior sexual history is not a mark of consent. It is not a warrant of disbelief. These are not merely legal propositions. They are basic truths about human beings that Canadian law, in its better moments, has chosen to honour.

The work, however, is not complete. In courtrooms across Canada, defence strategies still sometimes test the boundaries of the prohibition, and fact-finders — human beings with their own absorbed biases — still sometimes reason in ways that the law has declared impermissible. The twin myths rule does not guarantee that justice will be done. It creates the conditions under which justice has a better chance.

This document is written for educational and informational purposes only. It does not constitute legal advice and should not be relied upon as such. Readers facing legal issues should consult a qualified Canadian criminal defence lawyer. If you need assistance contact Neuberger & Partners LLP.