The California Court of Appeal found that the trial court erred in finding inadmissible evidence consisting of the deceased’s journal, and petitioner’s testimony regarding the effect reading it had on her. Here, petitioner was convicted of first degree murder and use of a firearm. Petitioner had relied on imperfect self-defense. The deceased was her husband, and his journal recounted his acts of abuse and violence against his homosexual companion, his stepdaughter, his rape of a friend’s girlfriend, and numerous beatings inflicted on his first wife. Because the Court of Appeal’s finding regarding the admissibility of this evidence is binding on a federal court, the sole issue was whether the exclusion was contrary to or an unreasonable application of clearly established federal law as determined by the Supreme Court of the United States, and if so, whether the error was “objectively unreasonable.” Here, the federal appellate court found that the excluded evidence went to the heart of petitioner’s defense and was critical to her ability to defend herself and violated her constitutional right to due process of law–the right to present a valid defense. It was objectively unreasonable, and likely had a substantial and injurious effect on the jury’s verdict per Brecht v. Abrahamson (1993) 507 U.S. 619, 638. Petitioner’s state of mind was critical, and her credibility was therefore crucial. Excluding corroboration from the victim himself excluded the only unbiased corroboration possible. Judge Noonan concurred and dissented, finding that the excluded evidence did not establish that petitioner’s fear was of an imminent peril. The evidence established that petitioner’s husband was going to kill her in the morning when he got up, and not that he was going to kill her at the moment she killed him around 5:15 a.m. as he lay prone on the bed.