## Facts

- Matthew Ducheneaux was a quadriplegic with severe spastic paralysis causing tremors, pain, and muscle spasms.
- Physicians prescribed medications, including Valium and Marinol, to manage his symptoms.
- Ducheneaux believed the prescribed drugs caused dangerous side effects and that smoked marijuana relieved his symptoms more effectively with fewer adverse effects.
- South Dakota law criminalized marijuana possession and contained no medical-use exception.
- Ducheneaux was arrested and charged with simple possession of marijuana.
- Before trial, the magistrate court initially ruled Ducheneaux could present a common-law necessity defense based on medical need, but the circuit court reversed on the State’s appeal.
- On remand, the magistrate court barred the necessity defense; the jury convicted Ducheneaux.
- The circuit court affirmed the conviction, and Ducheneaux appealed to the South Dakota Supreme Court.

## Issues

1. Whether South Dakota law permits a common-law necessity defense to simple marijuana possession based on medical necessity where the Legislature has provided no medical-use exception.
2. If the defense is theoretically available, whether Ducheneaux produced sufficient evidence to require a necessity instruction, particularly on the “no legal alternative” and proportionality elements.
3. Whether recognizing a medical-necessity defense in this context would conflict with the Legislature’s controlled-substances scheme and separation-of-powers principles.

## Decision

- The South Dakota Supreme Court affirmed Ducheneaux’s conviction.
- The court held that the common-law necessity defense was not available to justify marijuana possession under South Dakota’s controlled-substances statutes in the circumstances presented.
- The court further held that, even if necessity could apply in a narrow case, Ducheneaux did not satisfy the elements required to submit the defense to the jury, especially the requirement of no legal alternative.

## Legal Principles

- A narrow common-law necessity defense generally requires: (1) clear and imminent danger; (2) reasonable expectation that the illegal act will avert the danger; (3) no legal alternative; and (4) the harm caused is not disproportionate to the harm avoided.
- A defendant must produce evidence supporting each element before a court may instruct the jury on necessity.
- Where the Legislature has enacted a comprehensive controlled-substances scheme and has not created a medical exception, courts will not use common-law necessity to create an exception that effectively alters the statutory prohibition.
- Disagreement with the side effects or effectiveness of prescribed, lawful treatments does not, without more, establish the absence of legal alternatives for necessity purposes.
- In assessing proportionality in the controlled-substances setting, legislative judgments about the harms of prohibited drugs constrain case-by-case judicial rebalancing.

## Conclusion

The court upheld Ducheneaux’s marijuana-possession conviction, concluding that South Dakota’s statutory drug scheme left no room for a judicially created medical-necessity exception and that, in any event, Ducheneaux failed to show the lack of lawful alternatives needed to warrant a necessity instruction.


State v. Ducheneaux, 671 N.W.2d 841 (S.D. 2003)