## Facts

- Helen Wu, born in China, had a nonmarital relationship with Gary Wu and a son, Sidney.
- To avoid shame associated with an out-of-wedlock child, Wu returned to China and left Sidney in the United States with Gary’s family.
- On a later visit, Sidney told Wu he was beaten and poorly treated at home, which caused Wu intense distress and physical symptoms.
- Wu repeatedly expressed suicidal thoughts to Sidney and asked whether he would die with her.
- Wu strangled Sidney and attempted suicide but survived.
- The prosecution argued Wu killed Sidney to retaliate against Gary.
- The defense argued Wu, described as a “traditional” Chinese woman, acted during extreme emotional disturbance driven by guilt and fear of future mistreatment, believing she needed to die with Sidney to care for him in the afterlife.
- Wu testified she had no conscious memory of strangling Sidney and presented expert testimony addressing cross-cultural factors relevant to her mental state.

## Issues

1. Whether the trial court erred by refusing to instruct on unconsciousness where evidence supported a finding that Wu was unconscious during the killing.
2. Whether the trial court erred by refusing an instruction that the jury could consider Wu’s Chinese cultural background in deciding premeditation, malice, and intent to kill.

## Decision

- The court reversed the second-degree murder conviction and remanded for a new trial.
- It held the trial court had a duty to instruct on unconsciousness because evidence (including Wu’s claimed lack of memory and expert testimony about extreme disturbance) could support that defense.
- It held the trial court also erred by refusing an instruction permitting consideration of cultural background when evaluating mental-state elements and competing inferences about planning versus emotional disturbance.
- The court found the instructional errors prejudicial because a properly instructed jury could have acquitted or returned a lesser verdict.

## Legal Principles

- A trial court must instruct on a defense theory supported by substantial evidence, even if the evidence appears weak or conflicting.
- Unconsciousness (not caused by voluntary intoxication) is a complete defense because it negates the mental state required for homicide liability.
- Evidence bearing on a defendant’s mental state is relevant to premeditation, malice aforethought, and intent to kill; jurors may consider cultural background where it meaningfully informs those determinations.
- When the prosecution relies on the defendant’s statements as proof of planning, the defense may offer cultural and psychological context supporting alternative, non-premeditated explanations, including heat of passion.

## Conclusion

The court ordered a new trial because the jury was not instructed on two supported theories central to mens rea—unconsciousness and the relevance of cultural background—creating a reasonable possibility that the verdict would have differed with proper instructions.


People v. Wu, 235 Cal. App. 3d 614 (Cal. Ct. App. 1991)