Exclusion of exculpatory testimony as unreliable hearsay violates the defendant’s due process right to present a defense. Petitioner was charged with the 1986 killing of a woman. After a hearing outside the jury’s presence, the trial court excluded testimony of a man, Culver, who would have testified that he was incarcerated with petitioner’s brother shortly after the murder and the brother admitted killing the woman during a failed robbery attempt. Although the court found the statement was against the brother’s penal interest and therefore an exception to the hearsay rule, it excluded the evidence because it lacked the necessary indicia of reliability. Appellant was convicted of murder and sentenced to death. His conviction was affirmed by the California Supreme Court which found the trial court erred in excluding the evidence but evaluated the error under state law, finding no constitutional error where the trial court abused its discretion under normal evidentiary rules. Petitioner thereafter filed writ petitions, ultimately in the Ninth Circuit. Held: Reversed. The California Supreme Court found the evidence trustworthy enough that it should have been admitted. By failing to employ a constitutional standard of prejudice, its decision was therefore contrary to the United States Supreme Court’s opinion in Chambers v. Mississippi (1973) 410 U.S. 284. Questions of credibility are for the jury to decide. The facts of Chambers are materially indistinguishable from those in the present case; Chambers therefore mandates a different result than that reached by the California Supreme Court. The evidence was trustworthy, had substantial probative value, was highly material, and was necessary to the defense. No government interest outweighed the value of admitting the testimony. Due process encompasses the right to present a defense, which was denied here. The Constitutional error was not harmless beyond a reasonable doubt.