On January 8, the U.S. Supreme Court unanimously rejected indefinite delays in the federal review of death penalty cases when inmates are mentally incompetent to assist their attorneys. Writing for the Court, Justice Clarence Thomas said such appeals are usually based on established facts, not requiring further input from the defendant. "Given the backward-looking, record-based nature of most federal habeas proceedings, counsel can generally provide effective representation to a habeas petitioner regardless of the petitioner's competence," he said. "Attorneys are quite capable of reviewing the state-court record, identifying legal errors, and marshaling relevant arguments, even without their clients' assistance." The opinion consolidated the cases of Ryan v. Gonzales (Arizona) and Tibbals v. Carter (Ohio). In Carter's case, the Court left open the window for a temporary stay if his appeals rely on evidence outside the court record and if he might regain competence. "If a district court concludes that [Carter's] claim could substantially benefit from the petitioner's assistance, the district court should take into account the likelihood that the petitioner will regain competence in the foreseeable future," Thomas wrote. "Where there is no reasonable hope of competence, a stay is inappropriate and merely frustrates the state's attempts to defend its presumptively valid judgment."
Based on an earlier Court decision (Ford v. Wainwright (1986)), if an inmate is mentally incompetent at the time of his execution, he may not be put to death.
(D. Cassens Weiss, "Supreme Court Allows Some Limited Stays for Competency in Habeas Corpus Appeals," ABA Journal, January 8, 2013.) Read the full opinion. See Supreme Court and Mental Illness.