## Facts

- Donald G. Lannan, age 23, was prosecuted in St. Joseph County, Indiana, for molesting a 14-year-old girl (V.E.).
- At trial, the State introduced testimony from another girl describing prior, uncharged molestations by Lannan.
- V.E. also testified to additional, uncharged sexual encounters with Lannan beyond the charged incident, including similar episodes in Lannan’s truck.
- The trial court admitted the uncharged-acts evidence under Indiana’s “depraved sexual instinct” exception to the general rule excluding propensity evidence.
- The jury convicted Lannan of child molesting.

## Issues

1. Whether Indiana should retain the “depraved sexual instinct” exception allowing prior sexual misconduct evidence to show propensity in sex-offense prosecutions.
2. Whether Indiana should instead apply an approach consistent with Federal Rule of Evidence 404(b) to other-acts evidence.
3. Whether admission of the prior-acts evidence in Lannan’s trial required reversal.

## Decision

- The Indiana Supreme Court abandoned the “depraved sexual instinct” exception.
- The court adopted the philosophy and analysis of Federal Rule of Evidence 404(b) for evaluating evidence of “other crimes, wrongs, or acts.”
- The court held that other-acts evidence is inadmissible when offered solely to prove character and action in conformity with that character.
- Applying harmless-error review to Lannan’s conviction, the court affirmed because the challenged evidence did not have sufficient prejudicial impact given corroboration of V.E.’s account.

## Legal Principles

- Evidence of other crimes, wrongs, or acts may not be used to prove a defendant’s character to show action in conformity therewith.
- Other-acts evidence may be admissible for non-propensity purposes (e.g., motive, opportunity, intent, preparation, plan, knowledge, identity, absence of mistake or accident), subject to ordinary relevance and prejudice limits.
- Sex-offense prosecutions are not exempt from the general prohibition on propensity reasoning; prior sexual misconduct is not admissible merely to show a “depraved sexual instinct.”
- Even if other-acts evidence was admitted under an invalid theory, a conviction may stand if the error is harmless in light of the record as a whole.

## Conclusion

The Indiana Supreme Court eliminated the sex-offense-specific “depraved sexual instinct” exception and required Rule 404(b)-type analysis for other-acts evidence, while affirming Lannan’s conviction because any improper admission of prior-acts testimony was harmless.


Lannan v. State, 600 N.E.2d 1334 (Ind. 1992)