## Facts

- Perez and Victoria Mesa attended high school together about ten years earlier and had no current relationship.
- On September 30, 1988, Perez drove to Mesa’s home and parked nearby.
- While Mesa was outside warming up her car, Perez entered her house without her knowledge.
- When Mesa returned inside, Perez attacked her, beating her and stabbing her repeatedly with a kitchen steak knife.
- After the first knife broke, Perez went to the kitchen, obtained a second knife, and continued stabbing Mesa.
- Mesa died from multiple stab wounds; there was no evidence of robbery or sexual assault, and the motive was unclear.

## Issues

1. Whether substantial evidence supported the jury’s finding that the killing was willful, deliberate, and premeditated first-degree murder rather than second-degree murder.

## Decision

- The California Supreme Court reversed the Court of Appeal’s reduction of the conviction to second-degree murder.
- The court reinstated the jury’s first-degree murder verdict and the trial court’s judgment.
- The court held that, viewing the record in the light most favorable to the judgment, a rational jury could find premeditation and deliberation.

## Legal Principles

- On sufficiency review, the question is whether any rational trier of fact could find the elements beyond a reasonable doubt when the evidence is viewed in the light most favorable to the verdict.
- The premeditation-and-deliberation guideposts identified in People v. Anderson (planning, motive, and manner of killing) are descriptive aids for appellate review, not a required checklist.
- Premeditation and deliberation may be established without a clear motive when evidence of planning and/or manner reasonably supports a finding of reflection and a calculated decision to kill.
- Evidence suggesting planning may include selecting the victim and location, entering the home surreptitiously, and waiting to confront the victim under circumstances consistent with an ambush.
- The manner of killing may support deliberation where the attack shows persistence and an opportunity to reflect, including stopping to obtain a new weapon and then resuming the killing.
- Appellate courts may not reweigh evidence or substitute their judgment for the jury’s reasonable inferences under the substantial-evidence standard.

## Conclusion

The court held that the combination of Perez’s conduct in entering the victim’s home and the persistent stabbing—including rearming after the first knife broke—permitted a rational jury to find premeditation and deliberation even though the motive was uncertain, requiring reinstatement of the first-degree murder conviction.


People v. Perez, 2 Cal. 4th 1117 (Cal. 1992)