It also held that the convicted murderer Scott Pinholster, the respondent in the case, was not entitled to the habeas relief he had been granted by the United States Court of Appeals for the Ninth Circuit.

Scott Lynn Pinholster was convicted of two counts of first-degree murder in connection with the fatal stabbing of two men in the Tarzana neighborhood of Los Angeles, California, on January 9, 1982.

[2] The entire Ninth Circuit then reheard the case en banc, vacated the three-judge panel's opinion, and affirmed the District Court's decision to grant habeas relief.

Consequently, the en banc Ninth Circuit concluded that the California Supreme Court's decision to deny Pinholster such relief previously was "contrary to, or involved an unreasonable application of, clearly established Federal law" as per 28 U.S.C.

[6] The Strickland v. Washington standard for ineffective assistance of counsel was already deferential, requiring the defendant to rebut a "strong presumption" that attorneys have "made all significant decisions in the exercise of reasonable professional judgment" and show that the sentencing outcome was prejudiced.

The new evidence Pinholster wanted to present about substance abuse, criminal history and mental illness of his family members may have been considered aggravating if a jury found that it showed future dangerousness.

[11] In Pinholster's case Justice Alito would have held that the federal hearing was barred by §2254(e)(2) because the mitigating evidence could have been presented during the state court proceedings.

[12] Some defendants (and lower courts) have attempted to avoid the Pinholster bar on evidentiary hearings by applying Justice Breyer's concurring reasoning.

The majority opinion was written by Clarence Thomas and joined by Chief Justice John Roberts as well as Antonin Scalia, Anthony Kennedy, and (with the exception of part II) Samuel Alito.