Oregon v. Guzek, 546 U.S. 517 (2006), was a decision by the Supreme Court of the United States, which ruled that the Eighth Amendment to the United States Constitution does not grant criminal defendants facing the death penalty the right to introduce new evidence of their innocence during sentencing that was not introduced during trial.

[7] Seeking to avoid further errors at his fourth sentencing proceeding, the court also addressed the exclusion of alibi evidence that Guzek had sought to admit, which consisted of transcripts of testimony by his mother and grandfather stating he was with them at the time of the murder.

As the result of the opinion of SCOTUS the Oregon Supreme Court reviewed the case yet again in 2007 (State of Oregon vs. Randy Lee Guzek, 153 P.3d 101 (Ore. 2007) and determined that in accordance with the SCOTUS decision, that live alibi testimony would not be allowed but that prior transcript alibi testimony of the defendant's mother and grandfather would be admitted.

Although the sole remaining issue for the defendant was his right to have life without parole considered if he waived any ex post facto right, on May 5, 2010 as jury selection was starting Guzek wrote a pro-se 5-page brief demanding that life without parole (LWOP) be removed from consideration and the presiding judge, Judge Jack Billings so ordered.

[9] The United States Supreme Court unanimously reversed the Oregon Supreme Court, ruling that the Eighth Amendment's prohibition against cruel and unusual punishment did not create a right to introduce evidence of innocence in a defendant's death penalty sentencing phase if it had not been introduced in the trial phase.