## Facts

- Monte Durham, in his mid-20s, had a documented history of psychiatric problems and prior criminal convictions.
- At age 17, he was discharged from the Navy after a psychiatric evaluation found a profound personality disorder rendering him unfit for service.
- After later criminal charges, he was adjudged “of unsound mind” in lunacy proceedings and committed to St. Elizabeths Hospital, where he was diagnosed with psychosis and psychopathic personality.
- Durham was charged with housebreaking under District of Columbia law and was tried in the U.S. District Court for the District of Columbia without a jury.
- His sole defense was that he was of unsound mind at the time of the offense.
- The district court convicted him under then-prevailing insanity doctrine.

## Issues

1. Whether the trial court correctly allocated and applied the burden of proof once evidence of insanity was introduced.
2. Whether the court should abandon the M’Naghten-based insanity formulations (including the limited irresistible impulse gloss) and adopt a new standard of criminal responsibility.

## Decision

- The D.C. Circuit reversed and remanded.
- The court rejected continued reliance on the M’Naghten/irresistible impulse framework and adopted a new insanity standard.
- It held that “an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.”
- The court indicated that confusion and error regarding the insanity framework and burden rules at trial supported setting aside the conviction and requiring further proceedings under the new standard.

## Legal Principles

- A defendant is not criminally responsible if the unlawful act was the product of a mental disease or mental defect.
- Psychiatric testimony should not be forced into narrow cognitive (right-wrong) or volitional (irresistible impulse) categories that may distort clinical evidence.
- Experts may diagnose and describe mental disease or defect and its behavioral effects; the factfinder determines whether the criminal act was the product of that condition.
- Once “some evidence” of insanity is introduced, the prosecution bears the ultimate burden to prove criminal responsibility beyond a reasonable doubt.

## Conclusion

The D.C. Circuit replaced M’Naghten-style insanity tests with the Durham “product” rule and reversed Durham’s housebreaking conviction for reconsideration under the new standard, emphasizing a causal link between mental disease or defect and the unlawful act while preserving the factfinder’s role in determining responsibility.


Durham v. United States, 214 F.2d 862 (D.C. Cir. 1954)