## Facts

- Federal agents investigated an alleged heroin sale and conspiracy in New York involving Jose Figueroa, Angel Lebron, and Ralph Acosta.
- A DEA agent (the principal trial witness) participated in the operation and testified that, during negotiations, Lebron displayed heroin.
- No heroin was recovered; the government alleged Acosta fled and discarded the bag into a crowd during arrest.
- The informant who helped arrange the transaction did not testify at trial.
- The prosecution introduced evidence that Acosta had a 1968 conviction for selling heroin, asserting it showed intent and knowledge under Federal Rule of Evidence 404(b).
- Acosta’s defense theory disputed possession and participation in the charged event, not that any possession was innocent or accidental.
- The district court admitted the prior conviction with a limiting instruction that the jury could consider it only on intent.

## Issues

1. Whether Acosta’s prior heroin-sale conviction was admissible under Federal Rule of Evidence 404(b) to prove intent or knowledge when intent was not meaningfully disputed.
2. Whether the probative value of the prior conviction was substantially outweighed by unfair prejudice under Federal Rule of Evidence 403.
3. Whether admission of the prior conviction in a joint trial unfairly prejudiced Figueroa and Lebron such that limiting instructions could not cure the spillover effect.

## Decision

- The court vacated the convictions of all three defendants and remanded for a new trial.
- It held the district court erred in admitting Acosta’s prior heroin conviction because intent was not genuinely in dispute and the evidence carried a high risk of unfair prejudice.
- It further held the error was not harmless given the lack of recovered drugs, limited corroboration, and the central role of the DEA agent’s credibility.
- It concluded the prejudice from the prior-conviction evidence extended to the co-defendants in the joint trial and could not be reliably contained by limiting instructions.

## Legal Principles

- Rule 404(b) permits other-acts evidence only for a proper, non-propensity purpose tied to an actual disputed issue; a stated purpose such as “intent” is insufficient if intent is effectively conceded.
- Even when offered for a permissible purpose, other-acts evidence must be excluded under Rule 403 when its probative value is substantially outweighed by the danger of unfair prejudice.
- In a close case turning largely on a single witness’s credibility, admission of a defendant’s similar prior conviction presents heightened risk that the jury will rely on propensity reasoning.
- In joint trials, powerful other-acts evidence admitted against one defendant may create spillover prejudice to co-defendants; limiting instructions may not cure the effect where the government’s proof is otherwise thin and rests on a shared narrative.

## Conclusion

The Second Circuit ordered a new trial because admitting a co-defendant’s prior heroin conviction to prove intent—when intent was not meaningfully contested—created unfair prejudice under Rules 404(b) and 403 that tainted the joint trial and could not be treated as harmless error.


United States v. Figueroa, 618 F.2d 934 (2d Cir. 1980)