## Facts

- Ronald Jay Drew, age 22, was drinking at a bar in Brawley, California, in the early morning of October 26, 1975.
- After leaving money on the bar and finding it missing, Drew accused another patron of taking it, prompting an argument and a call to police.
- When officers arrived and attempted to escort Drew outside, Drew struck an officer, who fell and suffered a head injury.
- Drew had a history of mental illness and prior hospitalizations, including documented irrational assaultive behavior.
- Drew entered dual pleas of not guilty and not guilty by reason of insanity; the trial was bifurcated into guilt and sanity phases.
- In the sanity phase, two court-appointed psychiatrists testified Drew suffered from latent schizophrenia and, at the time of the offenses, likely lacked the ability to distinguish right from wrong and lacked capacity to conform his conduct to law.
- The jury, instructed under the then-governing M’Naghten test, found Drew legally sane.

## Issues

1. Whether California should retain the M’Naghten test for legal insanity or adopt the American Law Institute/Model Penal Code (ALI) formulation.
2. Whether requiring a defendant to prove insanity by a preponderance of the evidence (Evid. Code § 522) is constitutional.
3. Whether, in light of the evidentiary record and any change in the insanity standard, the sanity verdict could stand and what remedy was required.

## Decision

- The California Supreme Court abandoned the M’Naghten formulation and adopted an ALI-based insanity test.
- The court held Evid. Code § 522 is constitutional and may place on the defendant the burden to prove insanity by a preponderance of the evidence.
- The court found the failure to instruct the sanity jury under the newly adopted ALI test was prejudicial on this record.
- The judgment was reversed only insofar as it rested on the sanity finding, and the case was remanded for a new trial limited to insanity; the guilt verdict remained intact.
- The court applied the new insanity standard to this case and generally to nonfinal cases and trials in which the sanity phase began after the decision.

## Legal Principles

- Legal insanity in California (as of this decision) is shown if, because of mental disease or defect, the defendant lacked substantial capacity either (a) to appreciate the criminality/wrongfulness of the conduct or (b) to conform the conduct to the requirements of law.
- The insanity standard should account for both cognitive impairment (appreciation of wrongfulness) and volitional impairment (capacity for behavioral control), not solely knowledge-based criteria.
- A state may constitutionally assign the defendant the burden of proving insanity by a preponderance of the evidence, so long as the prosecution retains the burden to prove the elements of the charged offenses beyond a reasonable doubt.
- When an instruction omits a governing legal standard and the record would permit a reasonable jury to reach a different result under the correct standard, the error is prejudicial and requires a new trial on the affected issue.

## Conclusion

The court replaced the M’Naghten insanity test with an ALI-based standard incorporating both appreciation of wrongfulness and capacity to conform conduct to law, upheld the statutory allocation placing the burden of proving insanity on the defendant, and ordered a new trial limited to sanity because the jury had been instructed under the superseded standard.


People v. Drew, 22 Cal. 3d 333, 583 P.2d 1318 (Cal. 1978)