## Facts

- Stillman E. Wilbur, Jr. was tried in Maine for the killing of Claude Hebert in Hebert’s hotel room.
- The prosecution relied on Wilbur’s pretrial statement and circumstantial evidence that he intentionally killed Hebert.
- In the statement introduced by the State, Wilbur claimed he acted in a frenzy provoked by Hebert’s alleged homosexual advance.
- Under Maine law, homicide offenses were murder and manslaughter (not divided into degrees).
- The jury was instructed that the State had to prove beyond a reasonable doubt that the killing was unlawful and intentional.
- The jury was further instructed that Maine presumed malice from an unlawful, intentional killing, making the offense murder unless the defendant proved by a preponderance of the evidence that he acted in the heat of passion on sudden provocation, which would reduce the crime to manslaughter.
- Wilbur was convicted of murder; the Maine Supreme Judicial Court affirmed.
- Wilbur obtained federal habeas relief; the district court and First Circuit held Maine’s burden-shifting scheme violated due process.

## Issues

1. Whether due process permits a State to require a murder defendant to prove heat of passion on sudden provocation by a preponderance of the evidence to reduce the offense to manslaughter.
2. Whether a presumption of malice from an unlawful, intentional killing unconstitutionally relieves the State of proving beyond a reasonable doubt facts that distinguish murder from manslaughter.

## Decision

- The Supreme Court affirmed the grant of habeas corpus relief.
- Due process requires the prosecution to prove beyond a reasonable doubt every fact necessary to constitute the charged crime.
- Because Maine used the presence or absence of heat of passion on sudden provocation to determine whether an unlawful, intentional killing was murder or manslaughter, the State could not shift to the defendant the burden of persuasion on that fact.
- When the issue is properly presented, Maine must prove beyond a reasonable doubt the absence of heat of passion on sudden provocation.
- Justice Rehnquist, joined by Chief Justice Burger, concurred in the result, endorsing the outcome under the reasonable-doubt rule while cautioning against an expansive reading.

## Legal Principles

- The Fourteenth Amendment Due Process Clause requires the prosecution to prove beyond a reasonable doubt every fact necessary to constitute the crime charged.
- A State may not use presumptions or burden-shifting rules that, in operation, relieve the prosecution of proving beyond a reasonable doubt a fact that determines criminal culpability and the grade of the offense.
- Formal labels such as “affirmative defense” do not control; courts examine how state law functionally allocates proof on facts that differentiate offenses (here, murder versus manslaughter).

## Conclusion

Maine’s rule requiring a murder defendant to prove heat of passion on sudden provocation violated due process because it shifted to the defendant the burden of disproving a culpability-determining fact; once the issue is raised, the State must prove beyond a reasonable doubt the absence of heat of passion.


Mullaney v. Wilbur, 421 U.S. 684 (1975)