## Facts

- William Laurence Wetmore had a documented history of mental illness and had received psychiatric treatment.
- Wetmore developed a delusional belief that he owned certain property, including an apartment belonging to Joseph Cacciatore.
- Cacciatore left his apartment and returned several days later to find Wetmore inside wearing his clothes, cooking his food, and with the apartment in disarray; the door lock had been broken.
- After police arrested Wetmore, Cacciatore discovered numerous possessions missing, and Wetmore was charged with burglary.
- Wetmore pleaded not guilty by reason of insanity, and two court-appointed psychiatrists prepared reports describing his mental illness and delusion that the apartment was his.
- Wetmore waived a jury and submitted the case on the preliminary hearing transcript and the psychiatric reports under California’s bifurcated procedure (guilt phase, then insanity phase).
- At the guilt phase, the trial court excluded the psychiatric reports because they also described insanity and, relying on prior dictum, treated them as inadmissible to show lack of capacity to form specific intent.
- Based solely on the victim’s testimony, the court convicted Wetmore of second-degree burglary.
- At the insanity phase, the court considered the psychiatric reports, found Wetmore not guilty by reason of insanity, and ordered his commitment due to continuing insanity.
- Wetmore appealed the guilt-phase conviction, asserting the excluded psychiatric evidence directly negated the specific-intent element of burglary.

## Issues

1. Whether, in a bifurcated criminal trial, psychiatric evidence offered to show diminished capacity is admissible at the guilt phase to negate specific intent even if the same evidence also bears on legal insanity.
2. Whether excluding such evidence improperly prevents a defendant from rebutting an element the prosecution must prove beyond a reasonable doubt.

## Decision

- The California Supreme Court reversed the burglary conviction and remanded.
- The court held that evidence of diminished capacity is admissible at the guilt phase even if it also tends to show insanity.
- The court rejected the dictum relied on by the trial court that would bar mental-condition evidence at the guilt phase when it overlaps with insanity.
- The exclusion was prejudicial because the psychiatric reports were the only evidence directly addressing whether Wetmore formed the specific intent required for burglary.

## Legal Principles

- The prosecution must prove every element of the charged offense beyond a reasonable doubt, including specific intent where required.
- A defendant may present probative mental-condition evidence at the guilt phase to negate specific intent; such evidence cannot be excluded merely because it is also relevant to insanity.
- A defendant who, due to diminished capacity, did not form the specific intent required for the offense is entitled to acquittal of that specific-intent crime.
- Public safety concerns arising from acquittal on mens rea grounds are addressed through civil commitment procedures, not by maintaining a conviction for a crime requiring intent the defendant did not have.

## Conclusion

The court held that, in a bifurcated proceeding, psychiatric evidence showing diminished capacity must be admitted at the guilt phase when it directly rebuts specific intent, even if it also supports an insanity claim, and it reversed Wetmore’s burglary conviction because excluding the reports prevented a fair determination of the intent element.


People v. Wetmore, 22 Cal. 3d 318 (Cal. 1978)