United States v. John Riepe, 858 F.3d 552

A letter from John Riepe to M.B., a 15-year-old high school student, invited contact and included Riepe’s phone number; M.B.’s parents reported it to police.
Detective Kunde, posing as M.B. with parental consent, exchanged texts with Riepe that became explicitly sexual and arranged an in-person meeting at a church parking lot.
Riepe repeatedly professed affection, described sexual preferences and acts, suggested meeting at his house or a hotel, and confirmed plans shortly before the agreed meetup; officers arrested him at the meeting place.
The district court admitted evidence under Federal Rule of Evidence 404(b) that Riepe had prior contacts with two other teenage girls (A.M. and R.V.) to show plan, knowledge, and preparation; jury received a limiting instruction.
A jury convicted Riepe of attempted enticement of a minor (18 U.S.C. § 2422(b)); the district court sentenced him to 151 months’ imprisonment.
On appeal, Riepe challenged (1) sufficiency of the evidence to prove intent to persuade M.B. to engage in sexual activity and (2) admission of the 404(b) prior-act evidence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Sufficiency of evidence to show intent to persuade/enticement	Texts were sexually explicit, Riepe initiated sexual topics, arranged meeting and traveled to rendezvous — supports intent and substantial step toward commission	Texts show only interest in spending time; Kunde (undercover) pursued sex topics; lack of condoms and some non-sexual suggestions show no intent to have sex	Affirmed: viewing evidence in prosecution’s favor, jury reasonably found intent and substantial step toward enticement; texts and conduct support conviction
Admissibility of prior bad acts under Rule 404(b)	Prior unsolicited contacts with other teenage girls were relevant to plan, knowledge, preparation; similarity in kind and timing and limiting instruction reduced prejudice	Prior acts did not involve sexual propositions and risked unfair prejudice; should have been excluded under Rules 404(b) and 403	Affirmed: district court did not abuse discretion admitting 404(b) evidence; acts sufficiently similar and probative; any error would be harmless given overwhelming evidence and limiting instruction

United States v. Shinn, 681 F.3d 924 (8th Cir.) (elements and attempt standard for enticement of a minor)
United States v. Young, 613 F.3d 735 (8th Cir.) (intent inference from online sexual conversations)
United States v. Mora, 81 F.3d 781 (8th Cir.) (four-part test for admissibility under Rule 404(b))
United States v. Aranda, 963 F.2d 211 (8th Cir.) (Rule 404(b) construed as inclusionary; excludes only character-only evidence)
United States v. Pierson, 544 F.3d 933 (8th Cir.) (need for and review of Rule 403 balancing)
United States v. Turner, 781 F.3d 374 (8th Cir.) (harmlessness analysis when prior-act evidence admitted)