## Facts

- Around 4:00 a.m., a Los Angeles County sheriff’s deputy approached Russell David Pena and his girlfriend, Sara Marrufo, who were asleep in a parked car, and the deputy detected the odor of alcohol.
- Pena and Marrufo testified the deputy ordered them out, searched them, and subjected Marrufo—wearing a revealing costume—to an intrusive flashlight inspection.
- Marrufo was placed into the patrol car over protest; the deputy drove away, leaving Pena behind.
- Pena, after drinking, drove to follow the patrol car because he feared for Marrufo’s immediate physical safety.
- The deputy testified he drove Marrufo directly home and only then noticed Pena had followed; he then administered field sobriety tests and arrested Pena for driving under the influence.
- Pena and Marrufo testified the deputy stopped near railroad tracks before continuing and that Pena was arrested at Marrufo’s home without field sobriety tests.
- Pena was charged with DUI (former Veh. Code § 23102(a)) and two additional counts that were later dismissed.
- A first jury trial ended in a mistrial after the jury asked about a “justification” defense and was told it was unavailable; a second trial resulted in a DUI conviction and a one-year county jail sentence.
- Pena appealed, arguing the trial court wrongly refused to instruct on his justification theory (described as duress/necessity).

## Issues

1. Whether a necessity/duress-type justification defense is legally available to a charge of driving under the influence under former Vehicle Code § 23102(a).
2. Whether the trial court must instruct on that defense when substantial evidence supports that the defendant drove only to prevent imminent serious harm to another and lacked a reasonable alternative.

## Decision

- The appellate department reversed the DUI conviction.
- It held that a necessity/duress-type justification defense is available in a DUI prosecution absent a statutory exclusion.
- It held the evidence presented was sufficient to require a jury instruction on that defense.
- The refusal to instruct improperly removed a material defense theory from the jury and constituted reversible error.

## Legal Principles

- A justification defense described as duress/necessity may excuse otherwise criminal conduct when undertaken to avoid a greater, imminent harm, subject to traditional limiting elements (immediacy, lack of reasonable legal alternatives, and proportionality).
- Such a defense is not categorically limited to particular offenses; absent legislative negation, its availability depends on whether the evidence could satisfy the defense elements.
- A defendant is entitled to jury instructions on any legally recognized defense supported by substantial evidence, even if the supporting evidence is weak, inconsistent, or of doubtful credibility; credibility and factual disputes are for the jury.

## Conclusion

Because the justification defense was legally available to DUI and substantial evidence supported Pena’s claim that he drove only to protect his girlfriend from an imminent threat with no adequate alternative, the trial court’s failure to instruct the jury on that defense required reversal of the conviction.


People v. Pena, 149 Cal. App. 3d Supp. 14, 197 Cal. Rptr. 264 (App. Dep’t Super. Ct. L.A. Cnty. 1983)