Mersereau v. State, 286 P.3d 97

Appellant Adam J. Mersereau was convicted of one count of first-degree sexual abuse of a minor and eight counts of second-degree sexual abuse of a minor.
The State sought to admit uncharged misconduct evidence including nude photos of the victim and his brother, and pornographic websites; actual child-pornography images were excluded.
The district court held a competency hearing and found the four-year-old victim competent to testify; on appeal the court’s competency finding was found clearly erroneous and reversible.
Deputy Peech conducted a lengthy interview with the appellant; portions of the interview were played for the jury.
The majority found several evidentiary and trial-controlling errors requiring reversal and a new trial; the concurrence would have found some sufficiency issues and disagreed on others.
On remand, the district court shall enter judgments of acquittal on the eight second-degree counts if necessary and conduct a new trial consistent with this opinion.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Victim competency to testify	Mersereau contends the victim was not competent.	Court properly found competency after five-part test.	Competency ruling clearly erroneous; new trial required.
Admission of uncharged misconduct under 404(b)	Evidence of nude photos and porn websites probative of motive; proper under 404(b).	Gleason factors show probative value outweighs prejudice; limiting instructions available.	Abuse of discretion; prejudicial error requiring reversal and new trial.
District court comment on weight of evidence	Limiting statement about evidence weight unfairly influenced the jury.	Statement was a limiting instruction, not weight assessment.	Plain error; improper commentary requiring correction on retrial.
Voluntariness of appellant's statement to Deputy Peech	Statements obtained involuntarily via coercion and psychological manipulation.	Totality of circumstances shows voluntariness.	No plain error; statements voluntary under totality of circumstances.
Corroboration requirement instruction	Corroboration not required for victim testimony; instruction corrects weight.	No error given defense strategy; invited error doctrine applies.	Instruction improper; on retrial, jury should not receive no-corroboration instruction.

English v. State, 982 P.2d 139 (Wyo. 1999) (competency of child witnesses judged with deference to trial court)
Gruwell v. State, 254 P.3d 223 (Wyo. 2011) (deference to trial court on witness credibility and demeanor)
Gleason v. State, 57 P.3d 332 (Wyo. 2002) (Gleason 404(b) analysis framework for uncharged misconduct)
Carter v. State, 241 P.3d 476 (Wyo. 2010) (totality-of-the-circumstances approach to voluntariness)
Sweet v. State, 234 P.3d 1193 (Wyo. 2010) (prosecutorial/accusatory remarks and admission of interrogation excerpts)
Pendleton v. State, 180 P.3d 217 (Wyo. 2008) (responding to introduction of interrogation evidence; invited error context)