## Facts

- George Howard Mandoka, a member of the Saginaw Chippewa Tribal Nation, lived on the Isabella Reservation in Michigan.
- The prosecution alleged Mandoka repeatedly sexually abused his step-daughter (B.J.) and two nieces (J.G. and E.B.) over a period of years on tribal land.
- J.G. testified Mandoka touched her vagina under her clothing when she was nine and committed additional similar acts.
- E.B. testified Mandoka abused her between roughly ages ten and fourteen, with conduct escalating over time.
- B.J. testified Mandoka sexually abused her repeatedly while she was a minor in the household, including conduct charged as aggravated sexual abuse and related offenses under federal statutes.
- The government also presented testimony that the victims witnessed Mandoka physically assault his wife (the children’s mother/aunt figure), offered to explain fear, household control, and delayed reporting.
- A federal jury convicted Mandoka of multiple offenses under 18 U.S.C. §§ 2241, 2242, 2243, and 2244; the district court imposed concurrent sentences including life imprisonment.

## Issues

1. Whether testimony about Mandoka’s prior sexual assaults against J.G. and E.B. was admissible under Federal Rule of Evidence 413 and, if so, whether it should have been excluded under Rule 403 as unfairly prejudicial.
2. Whether testimony that the victims observed Mandoka physically assault his wife was admissible under Federal Rule of Evidence 404(b) for non-character purposes and, if so, whether it should have been excluded under Rule 403.

## Decision

- The Sixth Circuit affirmed Mandoka’s convictions and sentence.
- The court held the district court properly admitted prior sexual-assault evidence under Rule 413 and did not abuse its discretion under Rule 403.
- The court held the district court properly admitted domestic-violence evidence under Rule 404(b) to provide context for victim behavior and credibility and did not abuse its discretion under Rule 403.
- The court applied an abuse-of-discretion standard to the evidentiary rulings.

## Legal Principles

- In federal sexual-assault prosecutions, Rule 413 permits admission of evidence that the defendant committed other sexual assaults and allows propensity reasoning, subject to Rule 403.
- Under Rule 403, otherwise admissible evidence is excluded only when unfair prejudice substantially outweighs probative value; similarity to charged conduct and corroborative force can support high probative value, and limiting instructions may reduce prejudice.
- Rule 404(b) bars other-acts evidence offered only to prove character, but permits it for non-character purposes, including explaining victim fear, control within the household, delayed disclosure, and relationship context.
- Appellate review of Rule 413, Rule 404(b), and Rule 403 evidentiary determinations is deferential; reversal requires a clear error of judgment by the trial court.

## Conclusion

The Sixth Circuit upheld Mandoka’s convictions and concurrent life sentences, concluding the district court acted within its discretion in admitting prior sexual-assault evidence under Rule 413 and domestic-violence context evidence under Rule 404(b), and that neither category of evidence warranted exclusion under Rule 403.


United States v. Mandoka, 869 F.3d 448 (6th Cir. 2017)