429 U.S. 877, 97 S. Ct. 226, 50 L. Ed. 2d 160 (1976)
Appellant was convicted by a jury of murder in the second degree in Delaware Superior Court.1 The Delaware Supreme Court reversed and remanded with instructions to strike the murder conviction but to enter a judgment of conviction for manslaughter.2
The Delaware Supreme Court sustained the constitutionality of a Delaware statute requiring a criminal defendant raising an insanity defense to prove mental illness or defect by a preponderance of the evidence.3 The Delaware Code provides that it is an affirmative defense if at the time of the conduct the accused lacked substantial capacity due to mental illness or defect.4 If the defendant prevails, the verdict is not guilty by reason of insanity.5
When an affirmative defense is raised at trial, the defendant has the burden of establishing it by a preponderance of the evidence under Del. Code Ann., Tit. 11, §304 (1975).6 The Delaware Supreme Court held that Leland v. Oregon has not been overruled by Mullaney v. Wilbur either expressly or implicitly.7 An appeal was taken to the United States Supreme Court, which dismissed the appeal for want of substantial federal question.8
Whether Leland v. Oregon can be reconciled with In re Winship and Mullaney v. Wilbur?9
The Due Process Clause requires the prosecution to prove every element of the crime beyond a reasonable doubt.10 Mullaney prohibits states from shifting the burden of proof on an issue that bears on an essential element of the offense even when labeled an affirmative defense.11 Leland permits states to require defendants to prove insanity by a preponderance of the evidence.12
Leland v. Oregon can be reconciled with In re Winship and Mullaney v. Wilbur.15
Related opinions on this issue
Joined by Justice Marshall
Justice Brennan, joined by Justice Marshall, dissented from the dismissal of the appeal.16 He maintained that the case presents a substantial federal question on whether Leland remains reconcilable with Winship and Mullaney. Brennan reasoned that Mullaney invalidated a state rule shifting the burden to prove heat of passion because that issue relates to the defendant's state of mind and the elements of the crime.17
He further explained that insanity likewise concerns an essential element of mens rea and the appropriate punishment, so a state's characterization of it as an affirmative defense cannot avoid the Winship requirement.18 Brennan concluded that the summary dismissal was inappropriate because such dispositions carry precedential weight under Hicks v. Miranda and the erosion of Leland merits full briefing and argument.19