## Facts

- Federal prosecutors charged Ana Dolores Ruiz and others with conspiracy to possess with intent to distribute more than five kilograms of cocaine, in violation of 21 U.S.C. § 846.
- The case arose from an undercover Customs operation involving negotiations for a 70-kilogram cocaine transaction in Tampa, Florida.
- An undercover agent negotiated with a Colombian contact and a U.S.-based intermediary; Ruiz later contacted the agent using the code name “Lamento.”
- The government’s theory was that Ruiz acted as a broker by helping arrange the meeting between the buyer (Angel Santana) and the purported supplier (the undercover agent).
- Ruiz testified that she became involved to help her son-in-law address a pending federal drug matter and that she believed Santana was a government informant.
- Ruiz’s defense theory was that she honestly believed she was assisting a government-sanctioned operation, and therefore lacked the intent to knowingly and willfully join a drug-distribution conspiracy.

## Issues

1. Whether Ruiz was entitled to a requested mistake-of-fact (theory-of-defense) jury instruction where evidence supported her claim that she believed she was assisting law enforcement rather than joining a drug conspiracy.
2. Whether the refusal to give that instruction substantially impaired Ruiz’s ability to present her defense, requiring reversal.

## Decision

- The Eleventh Circuit reversed Ruiz’s conviction and remanded for further proceedings.
- The court held the district court erred by refusing Ruiz’s requested mistake-of-fact instruction.
- The error was reversible because it substantially impaired Ruiz’s ability to present her defense to the jury.
- The convictions of co-defendants Aviles and Perez were affirmed without opinion.

## Legal Principles

- A defendant is entitled to a requested theory-of-defense instruction when: (1) it correctly states the law, (2) it has an evidentiary foundation, and (3) the failure to give it substantially impairs the defense.
- A good-faith mistake of fact can negate the mens rea required for a criminal offense when the mistaken belief, if credited, would mean the defendant did not act knowingly or willfully.
- For a § 846 drug-conspiracy charge, evidence that a defendant believed she was assisting law enforcement rather than participating in an unlawful agreement can, if accepted by the jury, negate intent to join the conspiracy.
- General instructions on the elements of the offense may be insufficient when they do not explain how the defendant’s asserted mistake bears on the required mental state.

## Conclusion

The Eleventh Circuit reversed Ruiz’s § 846 conspiracy conviction because the jury was not instructed on her supported mistake-of-fact theory that she believed she was assisting a government operation, a belief that could negate the intent required to knowingly and willfully join a drug conspiracy.


United States v. Ruiz, 59 F.3d 1151 (11th Cir. 1995)