## Facts

- An undercover San Antonio police officer testified that on January 8, 1991, he went to an area near the 800 block of West Commerce in San Antonio after complaints that a man known as “Tito” was selling narcotics there.
- The officer approached the area near the Three Kings Lounge and was directed to a man walking up the street.
- The officer testified he watched the man’s face during a brief encounter (about 20–25 seconds) and bought narcotics packaged in a balloon.
- Testing later showed the balloon contained heroin and cocaine.
- After the buy, the officer identified Augustin Mora Carrillo from a mug-book photograph as the seller.
- Carrillo was indicted for one count of distributing heroin and cocaine in violation of 21 U.S.C. § 841.
- At trial, Carrillo argued mistaken identity, contending he was not the seller and was a few blocks away at the time of the transaction.
- To counter the mistaken-identity defense, the government presented testimony from two other officers who said they had observed Carrillo sell narcotics on two other occasions.
- Over defense objection, the district court admitted the other-officer testimony as extrinsic-act evidence under Federal Rule of Evidence 404(b) for the purpose of proving identity and gave a limiting instruction.
- The jury convicted Carrillo, and the district court sentenced him to 168 months’ imprisonment and five years’ supervised release.

## Issues

1. Did the district court err by admitting evidence of Carrillo’s other alleged drug sales under Rule 404(b) to prove identity, where the other acts did not share sufficiently distinctive characteristics with the charged offense?

## Decision

- The Fifth Circuit reversed the conviction and remanded.
- The court held that the government’s Rule 404(b) identity theory failed because the other alleged sales were not so unusual and highly similar to the charged offense as to function as a “signature.”
- Given that identity was the disputed point at trial, the improper admission was not harmless.

## Legal Principles

- Rule 404(b) generally bars evidence of other crimes, wrongs, or acts offered to show a defendant’s character and that the defendant acted in accordance with that character.
- Other-acts evidence may be admitted for a non-character purpose, including identity, but the proponent must show more than general similarity.
- When offered to prove identity, the extrinsic act must share a high degree of similarity with the charged offense and include distinctive features that mark the offense as the defendant’s handiwork, not merely traits common to similar crimes.
- Routine characteristics of street-level narcotics transactions (such as the use of small packaging and sales in similar areas) do not, without more, establish identity and risk inviting a propensity inference.
- Appellate review of Rule 404(b) rulings is for abuse of discretion, and reversal is warranted when an erroneous admission likely affected the verdict, especially where the case turns on a contested identification.

## Conclusion

The Fifth Circuit reversed Carrillo’s distribution conviction because the government used testimony about other alleged drug sales to argue identity, but the acts were not distinctive enough to qualify as “signature” evidence under Rule 404(b); with identity contested, the error could not be treated as harmless and required remand for further proceedings.


United States v. Carrillo, 981 F.2d 772 (1993)