Relevance Requires Defendant’s Knowledge: Limiting BDSM/Adult-Content Internet History Evidence in Strangulation Prosecutions Under M. R. Evid. 403

1. Introduction

State v. S. Belcourt (2026 MT 113) arises from a January 2022 report of a violent disturbance in Great Falls, Montana. The State prosecuted Sebastian Nathaniel Belcourt for strangulation of a partner or family member under § 45-5-215(1), MCA, along with unlawful restraint and resisting arrest. The victim, R.A., described repeated violence culminating in Belcourt grabbing her throat, impeding breathing and blood flow, and causing her to lose consciousness.

The central appellate dispute was evidentiary: Belcourt sought to introduce R.A.’s alleged Internet history (Fansly and FetLife) indicating interest in certain BDSM-related topics to support a defense theory that he grabbed her throat to sexually arouse her, not “to impede” breathing or circulation as required by the strangulation statute. The District Court excluded the Internet-history evidence under Mont. R. Evid. 403, while allowing inquiry narrowly focused on whether R.A. had communicated an interest in strangulation to Belcourt or had previously consented to it in a sexual context.

2. Summary of the Opinion

The Montana Supreme Court affirmed. It held the District Court did not abuse its discretion by excluding evidence of the victim’s Internet history under M. R. Evid. 403 because: (1) generalized evidence of interest in nonconventional sex acts was not relevant to whether Belcourt acted with the requisite mental state for strangulation, and (2) any minimal probative value was substantially outweighed by unfair prejudice and risk of confusing the issues.

The Court also rejected Belcourt’s constitutional and structural-error arguments, concluding the trial court’s limits still provided an adequate opportunity for confrontation and cross-examination, and the ruling was a routine evidentiary decision (not a defect affecting the trial’s framework).

3. Analysis

A. Precedents Cited

• State v. Twardoski, 2021 MT 179, ¶ 14, 405 Mont. 43, 491 P.3d 711: Cited for the abuse-of-discretion standard governing admissibility decisions and the general proposition that relevant evidence is admissible (subject to exclusionary rules like Rule 403). The Court used Twardoski to frame that the District Court had “broad discretion,” but that discretion must be exercised within the Rules of Evidence.
• State v. Hicks, 2013 MT 50, ¶ 14, 369 Mont. 165, 296 P.3d 1149 (quoting State v. Derbyshire, 2009 MT 27, ¶ 19, 349 Mont. 114, 201 P.3d 811): Provided the definition of abuse of discretion (“acts arbitrarily… or exceeds the bounds of reason, resulting in substantial injustice”). This benchmark supported affirmance because the trial court’s relevance-and-prejudice rationale was reasoned and record-based.
• State v. Derbyshire, 2009 MT 27, ¶ 19, 349 Mont. 114, 201 P.3d 811 (quoting State v. Mizenko, 2006 MT 11, ¶ 8, 330 Mont. 299, 127 P.3d 458): Reinforced that discretion is bounded by evidentiary rules, statutes, and constitutional protections; and that correctness review applies where rulings turn on interpreting those authorities. The Court used this framework to treat the limitation as a standard Rules 401/403 ruling rather than a misapplication of the Rape Shield Statute.
• State v. Quinlan, 2021 MT 15, ¶¶ 29-30, 403 Mont. 91, 479 P.3d 982 (citing Pointer v. Texas, 380 U.S. 400, 403, 85 S. Ct. 1065, 1068 (1965)): Established confrontation as a fundamental right under the federal and Montana constitutions. The Court relied on Quinlan to explain that confrontation does not guarantee limitless cross-examination; courts may limit cross to relevant issues.
• State v. Nelson, 2002 MT 122, ¶ 15, 310 Mont. 71, 48 P.3d 739: Cited via Quinlan for the proposition that limiting cross-examination does not necessarily violate confrontation. This supported the holding that excluding generalized Internet-history evidence did not, by itself, amount to a constitutional violation.
• State v. Wagner, 2013 MT 47, ¶ 37, 369 Mont. 139, 296 P.3d 1142: Quoted (via Quinlan) for the principle that the Confrontation Clause guarantees only an opportunity for effective cross-examination, not cross-examination “in whatever way” the defense wishes. This helped justify the trial court’s “narrowly tailored” permitted inquiry (communications about strangulation), while excluding collateral sexual-interest evidence.
• State v. Van Kirk, 2001 MT 184, ¶¶ 38-40, 306 Mont. 215, 32 P.3d 735: Used to reject the “structural error” label, confining structural error to defects that affect the trial framework. The Court treated the ruling as an ordinary evidence limitation under Rules 401 and 403, not a foundational breakdown of the adversarial process.

B. Legal Reasoning

1) The Court’s relevance focus: knowledge and the charged act.
The Court accepted the logical structure of Belcourt’s defense as presented on appeal: he claimed the throat-grabbing occurred for sexual arousal rather than to impede breathing or circulation (an element of § 45-5-215(1), MCA). Even under that theory, however, the Court emphasized a crucial evidentiary link: the only sexual-history evidence with meaningful relevance would be evidence tending to show Belcourt’s knowledge that R.A. desired or consented to strangulation specifically.

The proffered Internet evidence showed interests such as collars, restraints, submission, and discipline, but the Court stressed that “strangulation did not appear” among the indicated interests. Thus, the evidence did not materially increase the probability of a consequential fact—namely, that Belcourt lacked the culpable mental state because he believed strangulation was desired/consented to in that moment. In short: generalized BDSM interests were too remote from the charged conduct and too disconnected from the defendant’s mental-state narrative.

2) Rule 403 balancing: minimal probative value versus high unfair prejudice and confusion.
The Court approved the District Court’s explicit balancing under M. R. Evid. 403. Even if the Internet history had “a modicum” of relevance, the Court concluded its probative value was substantially outweighed by: (a) the danger of unfair prejudice to the victim (sexual humiliation and improper character inferences), and (b) confusion of the issues (shifting the jury’s attention from whether Belcourt impeded breathing/blood flow to whether the victim had “nonconventional” sexual interests).

Notably, the District Court also identified an additional reliability concern: because the sites were subscription-based, the victim could have an economic incentive to list a broad range of interests. The Supreme Court treated this as part of the conscientious judgment supporting exclusion—i.e., the evidence risked inviting speculation and collateral disputes over meaning, authenticity, and motive, while adding little to the disputed elements of strangulation.

3) Confrontation Clause: opportunity, not boundless scope.
The Court applied State v. Quinlan and related cases to hold there was no confrontation violation. The decisive fact was that the trial court did not foreclose the defense from pursuing the only line of inquiry that would have been tightly relevant to the mental-state theory: questions about whether R.A. had told Belcourt she wanted strangulation, had previously permitted it, or otherwise manifested consent/arousal when it occurred in a sexual context. The Constitution required an opportunity for effective cross-examination—not the admission of collateral sexual-content evidence that risked prejudice and distraction.

The opinion underscores an important practical point: the Court noted that, at trial, Belcourt’s counsel “did not cross-examine R.A. on this matter.” While the legal holding did not turn entirely on forfeiture, that observation reinforced the conclusion that the evidentiary limits did not, in fact, deprive Belcourt of a meaningful chance to test the relevant assertion (consent/communication regarding strangulation).

4) Rape Shield Statute and structural error arguments.
Belcourt argued “structural error” based on the premise that the District Court applied a Rape Shield analysis even though the Rape Shield Statute applies to “prosecutions under this part” (sex offenses) per § 45-5-511(2), MCA. The Supreme Court rejected the premise: the District Court expressed doubt the statute applied and ruled under Rules 401 and 403. Because the decision was an evidentiary limitation (not a defect in the trial framework), State v. Van Kirk foreclosed treating it as structural error.

C. Impact

1) A clarifying rule for “sexual context” defenses in non-sex-offense prosecutions.
The decision meaningfully clarifies that when a defendant in a non-sex-offense prosecution (here, felony strangulation) attempts to introduce sexual-interest evidence to negate mental state, Montana courts should demand a close fit between: (a) the charged act (strangulation), and (b) evidence showing the defendant’s knowledge of the alleged consent/interest in that act. General evidence of unconventional sexual interests—especially where the charged conduct is not among the expressed interests—may be excluded as irrelevant or as unfairly prejudicial under Rule 403.

2) Reinforcement of Rule 403 as a functional substitute for sexual-history screening when the Rape Shield Statute does not apply.
Without extending the Rape Shield Statute beyond its text, the Court endorsed Rule 403 as the operative mechanism to prevent trials from devolving into sexual-character adjudications when sexual-history material is collateral. This is likely to be influential in assault and domestic-violence cases where a defendant frames the conduct as consensual “sexual activity” but relies on broad sexual-interest evidence rather than act-specific consent/communication evidence.

3) Guidance for litigants: offer proof must be act-specific and linked to defendant knowledge.
Going forward, defendants seeking admission of sexual-interest evidence to negate mental state should expect courts to ask: Does it show the victim’s interest in the specific act alleged, and does it show the defendant knew of that interest before or during the incident? Evidence failing either prong is vulnerable under Rules 401 and 403.

4) Victim-protection and issue-framing in domestic violence prosecutions.
The opinion signals a strong institutional concern about “putting the victim on trial” for sexual interests and about guarding juries from inflammatory, stigmatizing evidence that has limited bearing on statutory elements. That stance may reduce the likelihood that adult-content creation or online sexual communities will be used for generalized impeachment in DV contexts absent tight relevance.

4. Complex Concepts Simplified

• Relevance (M. R. Evid. 401 & 402): Evidence is relevant if it makes a consequential fact more or less likely. If it does not help prove or disprove an element (or a valid defense tied to an element), it is generally inadmissible.
• Rule 403 balancing: Even relevant evidence can be excluded if it risks unfair prejudice (inviting decisions based on emotion or stigma), confusing the issues (distracting from the elements), or misleading the jury—especially when the evidence adds little probative value.
• Confrontation Clause limits: A defendant has the right to cross-examine witnesses, but not to ask any question on any topic. Judges may limit cross-examination to relevant subjects and still satisfy the constitutional requirement of an “opportunity” for effective cross-examination.
• Structural error: A rare category of error that so undermines the trial’s basic framework that reversal is automatic. Ordinary evidentiary rulings—even important ones—typically are not structural error.
• Rape Shield Statute (as referenced): A statute that restricts evidence of a victim’s sexual history in specified sex-offense prosecutions. Here, the Court emphasized the ruling was made under the Rules of Evidence rather than by extending the statute.

5. Conclusion

State v. S. Belcourt establishes a practical evidentiary rule for Montana courts: in a strangulation prosecution, generalized evidence of a victim’s online sexual interests (including BDSM-adjacent content) may be excluded under M. R. Evid. 403 where it does not specifically concern strangulation and does not show the defendant’s knowledge of any strangulation interest or consent. The decision reinforces that confrontation rights are satisfied when defendants retain a meaningful chance to ask the relevant, act-specific questions—while preventing trials from being derailed by stigmatizing, marginally probative sexual-history evidence.