State v. Walton: Plain-Error Limits on Unpreserved Evidentiary Claims, Non-Mandatory 404(b) Limiting Instructions, and Permissible “Blind Expert” Testimony in Child Sexual Abuse Trials

Precedents Cited

1) Standards of review, preservation, and plain error

• State v. McGhee, 2021 MT 193: Provided the general evidentiary review framework (abuse of discretion; de novo for legal interpretation) and supported the proposition that prejudice concerns about 404(b) evidence are reduced where evidence is properly admitted for non-propensity purposes and unfair prejudice does not outweigh probative value.
• State v. Sinz, 2021 MT 163: Reinforced the baseline rule that issues not raised below generally are not addressed on appeal.
• State v. Akers, 2017 MT 311: Supplied the Court’s plain-error test (fundamental right + manifest miscarriage of justice/fundamental fairness/integrity of process) and the “sparingly” admonition.
• State v. Trujillo, 2020 MT 128: Was central to rejecting Walton’s new Daubert argument; the Court quoted Trujillo for the rule that a “mere assertion” of constitutional implications is insufficient—an appellant must affirmatively demonstrate the plain-error criteria.

2) 404(b) pretrial procedure and notice

• State v. Dist. Ct. of the Eighteenth Jud. Dist., 2010 MT 263 (hereinafter Salvagni): Established the pretrial procedure for Rule 404(b) admissibility (disclosure; defense motion to exclude and State response; hearing and written decision with findings). In Walton, the Court treated Salvagni primarily as a due-process/notice safeguard and concluded that, on this record, Walton could not show a fundamental fairness/integrity problem warranting plain-error intervention.
• State v. Crider, 2014 MT 139: Reiterated and operationalized the Salvagni procedure; the Court relied on Crider to describe the three procedural steps and the purpose—adequate notice and an opportunity to object and prepare.

3) Limiting instructions and non-propensity use

• State v. Stroud, 210 Mont. 58: Walton invoked Stroud to argue trial courts must sua sponte give limiting instructions. The Court read Stroud as hortatory rather than mandatory (“should be done sua sponte”), undercutting the claim that omission automatically amounts to plain error.
• State v. Clemans, 2018 MT 187: Supported the Court’s key relevance rationale: where a defendant’s theory implies mistake/accident/lack of voluntariness (here, involuntary intoxication/compulsion), prior-acts evidence can be probative to rebut that impression for a non-propensity purpose.

4) Rule 403/404(b) balancing and distinguishing unfairly prejudicial prior acts

• State v. Pelletier, 2020 MT 249: Walton relied on Pelletier to argue improper admission and prejudice. The Court distinguished it: Pelletier involved an unsubstantiated fifteen-year-old allegation with “no probative value” for the offered purpose and high prejudice. In Walton, by contrast, Walton acknowledged the abuse occurred and the evidence bore directly on voluntariness—central to her defense.

5) Child sexual abuse “blind expert” testimony and anti-vouching principles

• State v. Robins, 2013 MT 71: The Court relied heavily on Robins to uphold expert testimony explaining the complexities of child sexual abuse, including delayed disclosure and seemingly contradictory behaviors, because jurors often lack common experience with these dynamics. Robins also framed the boundary: experts generally cannot directly comment on an alleged victim’s credibility.
• State v. Morgan, 1998 MT 268: Reinforced the admissibility and usefulness of expert testimony on child sexual abuse dynamics.
• State v. Byrne, 2021 MT 238: Cited for the anti-vouching rule—experts generally cannot directly opine on credibility of a particular victim.
• State v. Wienke, 2022 MT 116: Supported the proposition that such expert education can assist jurors in assessing credibility without becoming improper vouching, when testimony remains general rather than case-specific credibility endorsement.

Legal Reasoning

1) Salvagni compliance and plain-error posture

Walton’s procedural attack was not preserved below; accordingly, her path depended on plain-error review. The Court focused on whether the alleged procedural shortfall created a due process problem (lack of notice or opportunity to object). The record showed: (i) prior-act details appeared in the affidavit supporting the Information and later discovery; (ii) the State filed a motion in limine identifying the acts and articulating Rule 404(b)/403 grounds; (iii) Walton responded; and (iv) the District Court ruled on the record before openings, limiting the scope of testimony. With those safeguards present, the Court held Walton did not carry the burden to show a fundamental fairness or integrity-of-process violation.

2) Relevance of the prior acts to Walton’s theory (non-propensity purpose)

The Court treated the prior acts as relevant to a contested issue raised by Walton herself: whether her participation was voluntary or the product of coercion and involuntary intoxication (memory loss; claims Monte drugged her). The children’s testimony that Walton engaged “willing[ly]” and participated in drugging and abuse supported the State’s rebuttal of mistake/accident/involuntariness. That is classic 404(b) logic: using other-acts evidence to prove a material issue (knowledge, plan, absence of mistake/accident), not to show propensity.

3) Limiting instruction: encouraged, not mandatory—and prejudice assessment is contextual

Walton argued the trial court had an affirmative duty to issue a limiting instruction without request. The Court rejected that reading of State v. Stroud, and then evaluated prejudice in context: the evidence was admitted for a non-propensity purpose tied to the defense theory, the court restricted the testimony’s scope, and the State’s closing argument relied more heavily on Walton’s communications than on the prior-acts testimony. On “the totality of the circumstances,” the Court was not “firmly convince[d]” that the omission left the fairness of the trial unsettled.

4) Blind expert testimony: helpful general education vs. improper vouching

Walton attacked Dutton’s testimony from two angles: it was (a) unhelpful because not based on case-specific facts, and (b) impermissible vouching. The Court explained why these claims conflict: “blind expert” testimony is designed to provide general, research- and experience-based context without knowledge of the specific allegations. Under State v. Robins and State v. Morgan, that general context is precisely what can assist jurors, particularly regarding delayed disclosure and behaviors jurors may misinterpret. The vouching line was not crossed because Dutton did not opine that E.W. or R.H. were truthful or that abuse occurred—she offered generalized dynamics.

5) New Daubert challenge: forfeiture and failure to justify plain-error review

Walton’s reliability attack under Daubert was raised for the first time on appeal and was not meaningfully developed under the plain-error standard. Relying on State v. Trujillo, the Court held that merely labeling an error as constitutional does not suffice; the appellant must show why nonreview would produce a manifest miscarriage of justice or compromise the integrity of the process. Walton did not do so.

Impact

Although noncitable, the decision illustrates several practical, recurring points in Montana criminal litigation:

• Substantial notice can blunt Salvagni-based procedural attacks: Where discovery, charging materials, and targeted motions in limine give clear notice and an opportunity to respond, appellants may struggle to convert imperfect pretrial procedure into plain error.
• 404(b) disputes turn on the defense theory as much as the State’s theory: When a defendant argues involuntariness, mistake, or accident, prior acts may become highly probative to rebut that claim.
• Limiting instructions remain best practice—but omission is not automatically reversible: Especially where the evidence is admitted for a valid non-propensity purpose and the court limits the scope, the prejudice calculus may not support plain-error relief.
• Blind experts remain a stable feature in child sexual abuse trials: General testimony on delayed disclosure and abuse dynamics is repeatedly treated as helpful so long as it avoids case-specific credibility endorsements.
• Appellate reliability challenges must be preserved and argued with specificity: A late-raised Daubert complaint faces steep hurdles, particularly under plain-error standards.