## Facts

- Two young girls disappeared after leaving one child’s home to go to a nearby park in Yucaipa, California.
- A neighbor saw the girls near the defendant’s property and observed the defendant approach and speak to them as they appeared to enter his yard.
- The girls’ bodies were later found in a dumpster.
- Physical evidence supported an inference that the defendant took the girls into his house, restrained at least one, killed one by repeated blows with a glass bottle, then strangled the other, and later concealed evidence, including by burning his house (arson).
- The defendant was convicted of two counts of first degree murder on a theory of willful, deliberate, and premeditated killing, and one count of arson; the jury also found true a multiple-murder special circumstance.
- At the penalty phase, the prosecution presented aggravation evidence, and the defense sought to present mitigating evidence, including expert testimony about psychological conditions and likely adjustment to prison; portions were excluded by the trial court.
- The defendant received a death sentence, triggering automatic review.

## Issues

1. Whether substantial evidence supported findings that the two murders were willful, deliberate, and premeditated first degree murders.
2. Whether excluding defense mitigating evidence at the penalty phase—particularly expert testimony on psychological condition (including post-traumatic stress) and likely future behavior in prison—was error violating the right to present relevant mitigation, and if so, whether it was prejudicial.

## Decision

- The court affirmed the first degree murder convictions and the multiple-murder special circumstance.
- The court held the evidence was sufficient to permit the jury to infer planning and reflection from the sequence of events, restraint, manner of killing, and concealment.
- The court reversed the death sentence because the trial court erroneously excluded relevant mitigating expert testimony concerning psychological history and anticipated prison adjustment.
- The court found the exclusion prejudicial and remanded for a new penalty trial.

## Legal Principles

- On appellate review of sufficiency of the evidence, the judgment must be upheld if, viewing the record in the light most favorable to the verdict, substantial evidence supports each element beyond a reasonable doubt.
- Premeditation and deliberation may be inferred from the circumstances of the crime, including the manner and sequence of the killings and post-crime conduct; proof of a specific motive is not required.
- In a capital penalty phase, the defense must be allowed to present broad mitigating evidence relating to the defendant’s character, background, mental condition, and other circumstances that could support a sentence less than death.
- Expert testimony bearing on psychological impairment and likely nonviolent adjustment to prison can be relevant mitigation; excluding such evidence may violate constitutional limits on restricting mitigation.
- Penalty-phase error is prejudicial when excluded mitigating evidence could reasonably have affected at least one juror’s sentencing choice.

## Conclusion

The court upheld the first degree murder convictions and special circumstance because substantial evidence supported findings of premeditation and deliberation, but it reversed the death sentence and ordered a new penalty trial due to prejudicial exclusion of relevant mitigating expert evidence.


People v. Lucero, 44 Cal. 3d 1006, 750 P.2d 1342 (Cal. 1988)