 Patterson v. New York

Patterson v. New York, 432 U.S. 197 (1977), is a legal case heard by the United States Supreme Court regarding the constitutionality under the Fourteenth Amendment's Due Process Clause of burdening a defendant with proving the affirmative defense of extreme emotional disturbance as defined by New York law.The court found that the State of New York had reclassified provocation ("extreme emotional disturbance") as an excuse (an affirmative defense requiring proof by preponderance of the evidence), rather than a circumstance negating the mental element (mens rea) which the prosecution had to prove beyond a reasonable doubt, as was the situation in "Mullaney v. Wilbur" (1975).