Holding: Review under the federal habeas law is limited to the record that was before the state court which ruled on the claim on the merits. Moreover, on the record that was before the state court, Pinholster was not entitled to federal habeas relief.
Plain English Holding: When an inmate challenges his state death sentence on the grounds that his trial counsel was ineffective in failing to present adequate mitigating evidence, a federal habeas court may only consider the evidence the inmate presented in support of that claim in the state courts. The Ninth Circuit erred in concluding that, on the basis of the state record alone, the inmate was entitled to habeas relief on his ineffective assistance of counsel claim.
Judgment: Reversed, 7-2, in an opinion by Justice Clarence Thomas on April 4, 2011. The Chief Justice and Justices Scalia and Kennedy joined the decision in full; Justice Alito joined the decision as to all but Part II of the Courtâ€™s opinion; Justice Breyer joined the decision as to Parts I and II, and Justices Ginsburg and Kagan joined the decision as to Part II. Justice Alito filed a separate opinion concurring in part and concurring in the judgment; Justice Breyer also filed a separate opinion concurring in part and dissenting in part. Justice Sotomayor filed a dissenting opinion, which Justices Ginsburg and Kagan joined in part.