In a 5–4 decision written by Justice Clarence Thomas, the Court held that the District Court had not abused its discretion when it refused to grant an evidentiary hearing to convicted murderer Jeffrey Timothy Landrigan who had instructed his defense counsel not to put on any mitigation case during the sentencing phase of a capital murder trial.

On appeal, a three-judge panel of the Ninth Circuit affirmed this decision, but the full Ninth Circuit subsequently reheard the case en banc and reversed, holding that Landrigan was entitled to a hearing because, contrary to the District Court's conclusion, he had made a "colorable" claim that he had received ineffective assistance of counsel that fell below the standard outlined by the Supreme Court in Strickland v. Washington.

The Court reversed the en banc Ninth Circuit, holding that the District Court was entirely justified in refusing to grant him an evidentiary hearing, as well as in concluding that, even if he were permitted to further develop the factual record at such a hearing, he would still not be entitled to habeas relief:[5] Regardless of what [additional] information counsel might have uncovered in his investigation, Landrigan would have interrupted and refused to allow his counsel to present any such evidence.

They also said Landrigan was present when defense counsel told the sentencing court that he had informed the defendant of the importance of mitigating evidence in capital proceedings.

[4] The dissenting opinion was written by Justice John Paul Stevens and joined by David Souter, Ruth Bader Ginsburg, and Stephen Breyer.

He also argued that the majority engaged in "pure guesswork" by reasoning that, were they to grant Landrigan an evidentiary hearing, it would not have made a difference in his sentencing.

Stevens' dissent concluded that the en banc Ninth Circuit's "narrow holding that the District Court abused its discretion in denying respondent an evidentiary hearing should be affirmed.