Program in Public Law

Clark v. Arizona

Clark was convicted of first-degree murder in an Arizona state court. At trial, the defense tried to present evidence that, due to mental illness, Clark did not “knowingly and intentionally” commit the murder. The trial court refused to admit the evidence, ruling that it could only be used to establish insanity as an affirmative defense. The trial court then ruled that Clark’s evidence of mental illness did not meet the burden of proof required for the insanity defense, which requires proof that the defendant had a qualifying mental illness that prevented him from understanding that the criminal act was wrong. Clark appealed, arguing that the narrowness of the insanity law and the trial court’s refusal to permit evidence of mental illness to negate the intent requirement for murder violated Clark’s right to Due Process under the Fourteenth Amendment. The court of appeals affirmed the trail court’s decision, and the Arizona Supreme Court denied discretionary review.

Questions Presented:
1. Whether Arizona's insanity law, as set forth in A.R.S. § 13-502 (1996) and applied in this case, violated Petitioner's right to due process under the United States Constitution, Fourteenth Amendment.
2. Whether Arizona's blanket exclusion of evidence and refusal to consider mental disease or defect to rebut the state's evidence on the element of mens rea violated Petitioner's right to due process under the United States Constitution, Fourteenth Amendment.

Decision under Review (unpublished)