On March 24, 2009, the Supreme Court decided Knowles v. Mirzayance, No. 07-1315.
Alexandre Mirzayance confessed to killing his cousin but entered pleas of not guilty and not guilty by reason of insanity. Under California procedure, a defendant's guilt and the viability of an insanity defense are determined by the same jury in separate proceedings. In the guilt phase of his trial, Mirzayance presented medical testimony that, because of his mental condition, he was incapable of the premeditation or deliberation necessary for first-degree murder. The jury nevertheless found him guilty.
Mirzayance's lawyer then recommended that he withdraw his insanity defense, reasoning that proving the defense would require the jury to believe the very evidence about his mental condition that it had just rejected in finding him guilty. Mirzayance accepted this advice and was convicted. The California state courts denied his subsequent appellate assertion that his lawyer's advice to withdraw the insanity defense amounted to ineffective assistance of counsel. He then sought a writ of habeas corpus from the federal courts on the same ground—this time with greater success. The federal district court granted the writ, reasoning that Mirzayance "had nothing to lose" by pursuing the defense and that the lawyer's advice to withdraw it therefore was deficient, regardless of how unlikely success on the defense might be. The Court of Appeals for the Ninth Circuit affirmed.
The Supreme Court unanimously reversed and directed that the writ of habeas corpus be denied. The Court held that the state appellate court's denial of Mirzayance's ineffective-assistance claim did not violate clearly established federal law because the "nothing to lose" standard applied by the federal courts below had no support in previous Supreme Court decisions. Whether the Court gave substantial deference to the state court's decision or considered the question de novo, it concluded that the counsel's legal advice to abandon the insanity defense, given after thorough investigation of the law and facts and consideration of the plausible options, did not violate any "prevailing professional norms." And the defendant also failed to show that he was prejudiced by the advice, even if flawed, because there was no reasonable possibility that the result would have been different if he had pursued the defense.
Justice Thomas delivered the opinion of the Court, in which Chief Justice Roberts and Justices Stevens, Kenndy, Breyer, and Alito joined, and in which Justices Scalia, Souter, and Ginsburg joined in part.