Patterson v. New York

Background

A man saw his estranged wife with another man, entered the house, and shot that man twice in the head. He admitted the killing and was tried for second‑degree murder under New York law, which defines murder by intent and causation. New York also allows an affirmative defense called “extreme emotional disturbance,” which, if proved by a preponderance of the evidence, reduces murder to manslaughter.

Reasoning

The Court considered whether it violates the Constitution to require the defendant to prove that his emotional state reduced his blameworthiness. The jury was told the State must prove death, intent, and causation beyond a reasonable doubt, and that the defendant must prove emotional disturbance by a preponderance. The Court held New York’s allocation did not deny due process because the core crime elements were proved beyond a reasonable doubt and the disturbance rule is a separate, historically recognized affirmative defense.

Real world impact

The immediate result was that the murder conviction was affirmed. The decision allows states to keep similar rules requiring defendants to prove certain mitigating factors by a lower standard, so long as prosecutors still prove the elements of the crime beyond a reasonable doubt. Legislatures retain room to design offenses and defenses subject to constitutional limits.

Dissents or concurrances

A dissent argued the ruling weakens prior decisions protecting the presumption of innocence, saying factors like heat of passion historically required prosecutors to disprove them beyond a reasonable doubt.