## Facts

- Michael Hendershott was charged with third-degree assault for physically attacking his girlfriend and causing bodily injury.
- Third-degree assault under Colo. Rev. Stat. § 18-3-204 required proof that the defendant acted “knowingly” or “recklessly” in causing bodily injury.
- Before trial in county court, the People moved to exclude psychiatric/psychological evidence that Hendershott suffered from a brain disorder that impaired his ability to form the required culpable mental state.
- Hendershott did not offer the evidence to establish legal insanity; he offered it only to create reasonable doubt that he acted “knowingly” or “recklessly” as charged.
- The trial court granted the motion and barred the expert testimony, reasoning that Colorado’s statutory “impaired mental condition” provision allowed such evidence only in prosecutions for specific-intent crimes, not general-intent crimes like third-degree assault.
- The jury convicted Hendershott of third-degree assault.
- Hendershott appealed, and the district court affirmed the conviction.
- The Supreme Court of Colorado granted certiorari to review whether the exclusion of the mental-condition evidence was proper.

## Issues

1. Does due process allow a court to categorically exclude otherwise admissible evidence of a mental disease or defect (short of insanity) when the defendant offers it to rebut the mens rea element of a general-intent crime such as third-degree assault?

## Decision

- No. The Colorado Supreme Court held that a blanket exclusion of competent mental-disease-or-defect evidence offered to contest the prosecution’s proof of mens rea violates due process.
- The court reversed the judgment affirming Hendershott’s conviction.
- The case was remanded for further proceedings consistent with the opinion, including a new trial at which relevant, otherwise admissible mental-condition evidence could be presented for the limited purpose of disputing whether Hendershott acted “knowingly” or “recklessly.”

## Legal Principles

- Due process requires the prosecution to prove every element of the charged offense beyond a reasonable doubt, including the culpable mental state when the legislature has made mens rea an element.
- A defendant must be allowed to present competent, relevant evidence that tends to negate an element of the offense; a rule that blocks an entire category of such evidence can violate due process by reducing the prosecution’s burden in practice.
- Colorado’s statutory scheme for insanity (an affirmative defense) does not prevent a defendant from using mental-disease-or-defect evidence, short of insanity, as rebuttal evidence directed at whether the required mens rea existed.
- Even in a general-intent prosecution, expert testimony about a mental disease or defect may be admissible for the limited purpose of helping the factfinder decide whether the defendant actually formed (or was capable of forming) the charged culpable mental state.
- Trial courts may still apply ordinary evidentiary limits (relevance, foundation, reliability, and risk of juror confusion) and may use limiting instructions to confine the jury’s use of the evidence to the mens rea question.

## Conclusion

Hendershott held that when a general-intent statute requires proof that the defendant acted knowingly or recklessly, due process is violated if the court bars the defendant from presenting otherwise admissible mental-disorder evidence offered solely to cast doubt on that mens rea; the conviction was reversed and the case remanded for proceedings allowing such evidence to be considered for the limited purpose of contesting the culpable mental state element.


Hendershott v. People, 653 P.2d 385 (1982)