William John Duncan v. The State of Wyoming

Wyoming Supreme Court·Decided July 30, 2026·No. S-25-0236·Published

Opinion

THE SUPREME COURT, STATE OF WYOMING

2026 WY 86

APRIL TERM, A.D. 2026

July 30, 2026

WILLIAM JOHN DUNCAN,

Appellant (Defendant),

v. S-25-0236

THE STATE OF WYOMING,

Appellee (Plaintiff).

Appeal from the District Court of Sweetwater County The Honorable Suzannah G. Robinson, Judge

Representing Appellant: Office of Public Defender: Patricia L. Bennett, State Public Defender;* Kirk A. Morgan, Chief Appellate Counsel; Sean H. Barrett, Senior Assistant Appellate Counsel. Argument by Mr. Barrett.

Representing Appellee: Keith G. Kautz, Attorney General; Jenny L. Craig, Deputy Attorney General; Kristen R. Jones, Senior Assistant Attorney General; Donovan Burton, Assistant Attorney General. Argument by Mr. Burton.

*An Order Substituting Patricia L. Bennett for Brandon Booth was entered on July 16, 2026.

Before BOOMGAARDEN, C.J., and GRAY, FENN, JAROSH, and HILL, JJ.

NOTICE: This opinion is subject to formal revision before publication in Pacific Reporter Third. Readers are requested to notify the Clerk of the Supreme Court, Supreme Court Building, Cheyenne, Wyoming 82002, of any typographical or other formal errors so that correction may be made before final publication in the permanent volume. FENN, Justice.

[¶1] A jury convicted William J. Duncan of six counts of sexual exploitation of a child, one count of endangering a child, and one count of unlawful contact. The district court sentenced Mr. Duncan to an aggregate term of 21 to 30 years in prison for the sexual exploitation convictions, followed by five years of supervised probation. The district court sentenced Mr. Duncan to 180-day jail sentences for the endangering a child and unlawful contact convictions, with those sentences to run concurrently with each other but consecutively to the sentences imposed for the sexual exploitation convictions. On appeal, Mr. Duncan challenges the sufficiency of the evidence supporting three of the six sexual exploitation convictions in violation of Wyoming Statute § 6-4-303(b)(ii) (2021). He argues digital penetration and penetration with a sexual device do not constitute “explicit sexual conduct” as defined under Wyoming Statute § 6-4-303(a)(iii) (2021). Alternatively, if that conduct falls within the statute, he contends the jury may have returned a nonunanimous verdict or improperly convicted him multiple times for the same underlying conduct. He also argues on one of the six counts the State failed to prove he “enticed” the minor child to engage in “explicit sexual conduct.” Finally, he asserts his aggregate sentence constitutes cruel punishment in violation of Article 1, Section 14 of the Wyoming Constitution. We affirm.

ISSUES

[¶2] Mr. Duncan presents two issues on appeal, which we rephrase and restate as the following three issues:

I. Did the State present sufficient evidence at trial to support Mr. Duncan’s convictions on Counts II, III, and V for sexual exploitation of a child?

II. If his convictions on Counts II and V are supported by sufficient evidence, did the district court commit plain error by failing to adequately instruct the jury they needed to unanimously agree which specific conduct formed the basis for each count?

III. Does Mr. Duncan’s sentence constitute cruel punishment in violation of Article 1, Section 14 of the Wyoming Constitution?

FACTS

[¶3] Mr. Duncan’s crimes involved four minor children, his stepdaughter/adopted

1 daughter1 (Minor Child), two of the Minor Child’s friends (Friend #1 and Friend #2), and Mr. Duncan’s son (Stepbrother). When the Minor Child was approximately eight years old, her mother met Mr. Duncan. The two later married and, together with their children, they moved into Mr. Duncan’s home. When Mr. Duncan entered the Minor Child’s life, she had a strained relationship with her biological father. Mr. Duncan assumed a parental role by, in the Minor Child’s words, “stepp[ing] up and t[aking] care of [her].”

[¶4] When the Minor Child was 12 years old, Mr. Duncan started to have sexual conversations with the Minor Child. In some of these conversations, Mr. Duncan asked the Minor Child to engage in sexual conduct with Friend #1 and Friend #2, while they were sleeping over at the home shared by the Minor Child and Mr. Duncan. Mr. Duncan would send the Minor Child text messages telling her to perform sexual acts on Friend #1, which included asking the Minor Child to use sexual devices on Friend #1, which Mr. Duncan had purchased for the Minor Child. On another occasion, Mr. Duncan sent the Minor Child a link to a pornographic video depicting three individuals engaged in sexual activity and asked the Minor Child to engage in the same conduct with Friend #1 and Friend #2, both of whom were 12 years old at the time. The Minor Child, Friend #1, and Friend #2 complied with Mr. Duncan’s request and engaged in the conduct for a brief period.

[¶5] In addition to encouraging the Minor Child to engage in sexual acts with her friends, Mr. Duncan encouraged the Minor Child to engage in sexual conduct with his son, the Minor Child’s Stepbrother. The Minor Child began having sexual relations with her Stepbrother when she was 12 years old and her Stepbrother was 14 years old, which was also around the same time Mr. Duncan was encouraging her to engage in sexual activity with Friend #1 and Friend #2. The Minor Child’s sexual relationship with her Stepbrother continued from July 2022 until August 2024. In August 2024, when the Minor Child was 14 years old and her Stepbrother was 17 years old, the Stepbrother ended the sexual relationship with the Minor Child when Mr. Duncan adopted the Minor Child, because the Stepbrother was no longer comfortable continuing with the relationship. Around this same time, Mr. Duncan text messaged the Minor Child and told her to: “Go lay on [your Stepbrother’s] bed and play with your p[****].” Mr. Duncan told the Minor Child if she did what he asked, her Stepbrother would not be able to tell her no.

[¶6] In October 2024, law enforcement received an anonymous report concerning the Minor Child having sexual relations with her Stepbrother. A detective met with the Minor Child’s mother and requested performing a forensic interview of the Minor Child. However, the mother declined and stated the matter would be addressed at home. The Minor Child later told her mother she had been having sexual relations with her Stepbrother, and Mr. Duncan had been encouraging the behavior.

1 At the outset of the period of the charged conduct, the Minor Child was Mr. Duncan’s stepdaughter. However, Mr. Duncan adopted the Minor Child in July 2024, approximately eight months before the State charged him.

2 [¶7] At some point, Mr. Duncan messaged the Minor Child and instructed her to “go in and permanently delete all [of her] deleted messages.” He further told her that he needed to know exactly what the Minor Child had said because what she’s “done . . . could destroy [their] family, businesses and way of life.” The Minor Child’s mother later confronted Mr. Duncan with the Minor Child present. During the confrontation, Mr. Duncan yelled at the Minor Child and told her to “keep [her] mouth shut . . . and if [she] keep[s] [her] mouth shut, nothing bad would happen and [she] just need[ed] to stop talking.” He then placed his hand over the Minor Child’s mouth, so the Minor Child bit his hand, pulled away, and left the vicinity.

[¶8] On January 20, 2025, law enforcement responded to a report of a domestic dispute at a counseling office and was directed to a back room, where officers contacted the Minor Child. Detectives conducted a forensic interview of the Minor Child and completed a forensic download of her phone. Following an investigation, Mr.

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William John Duncan v. The State of Wyoming, (Wyo. 2026).

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