Detrich v. Ryan

A petition for habeas corpus on a penalty-phase ineffective assistance of counsel claim is granted when: the state post-conviction court unreasonably applied federal law and the deficient performance prejudiced the defense.

Detrich was sentenced to death by an Arizona judge after a jury convicted him of murder, kidnapping, and sexual abuse. After exhausting his state remedies, Detrich filed a petition for a writ of habeas corpus in federal district court, alleging that his trial counsel was unconstitutionally ineffective by failing to investigate and present mitigating evidence, including history of abuse and expert neuropsychological testimony, during the sentencing hearing. This evidence was presented during post conviction relief. The district court denied relief and Detrich appealed. The Ninth Circuit reversed. The United States Supreme Court granted certiorari and vacated and remanded. The Ninth Circuit Court found that a petition for habeas corpus on a penalty-phase ineffective assistance of counsel claim is granted when: the Arizona post-conviction court unreasonably applied the clearly established federal law of Strickland; and the deficient performance prejudiced the defense, since there was a “reasonable probability” that the sentencing judge would have imposed a sentence less than death if sentencing-hearing council had obtained and presented expert testimony and reports of the defendant’s neuropsychological function. REVERSED AND REMANDED.