KENNEDY, J., delivered the opinion of the Court, in which GINSBURG, BREYER, SOTOMAYOR, and KAGAN, JJ., joined. THOMAS, J., filed a dissenting opinion. ALITO, J., filed a dissenting opinion, in which ROBERTS, C. J., and THOMAS, J., joined.
A Colorado jury convicted petitioner Peña-Rodriguez of harassment and unlawful sexual contact. Following the discharge of the jury, two jurors told defense counsel that, during deliberations, Juror H. C. had expressed anti-Hispanic bias toward petitioner and petitioner’s alibi witness. Counsel, with the trial court’s supervision, obtained affidavits from the two jurors describing a number of biased statements by H. C. The court acknowledged H. C.’s apparent bias but denied petitioner’s motion for a new trial on the ground that Colorado Rule of Evidence 606(b) generally prohibits a juror from testifying as to statements made during deliberations in a proceeding inquiring into the validity of the verdict. The Colorado Court of Appeals affirmed, agreeing that H. C.’s alleged statements did not fall within an exception to Rule 606(b). The Colorado Supreme Court also affirmed, relying on Tanner v. United States, 483 U. S. 107, and Warger v. Shauers, 574 U. S. ___, both of which rejected constitutional challenges to the federal no-impeachment rule as applied to evidence of juror misconduct or bias.
Held: Where a juror makes a clear statement indicating that he or she relied on racial stereotypes or animus to convict a criminal defendant, the Sixth Amendment requires that the no-impeachment rule give way in order to permit the trial court to consider the evidence of the juror’s statement and any resulting denial of the jury trial guarantee.
(a) At common law jurors were forbidden to impeach their verdict, either by affidavit or live testimony. Some American jurisdictions adopted a more flexible version of the no-impeachment bar, known as the “Iowa rule,” which prevented jurors from testifying only about their own subjective beliefs, thoughts, or motives during deliberations. An alternative approach, later referred to as the federal approach, permitted an exception only for events extraneous to the deliberative process. This Court’s early decisions did not establish a clear preference for a particular version of the no-impeachment rule, appearing open to the Iowa rule in United States v. Reid, 12 How. 361, and Mattox v. United States, 146 U. S. 140, but rejecting that approach in McDonald v. Pless, 238 U. S. 264.
The common-law development of the rule reached a milestone in 1975 when Congress adopted Federal Rule of Evidence 606(b), which sets out a broad no-impeachment rule, with only limited exceptions. …
(b) Some version of the no-impeachment rule is followed in every State and the District of Columbia, most of which follow the Federal Rule. At least 16 jurisdictions have recognized an exception for juror testimony about racial bias in deliberations. Three Federal Courts of Appeals have also held or suggested there is a constitutional exception for evidence of racial bias.
In addressing the common-law no-impeachment rule, this Court noted the possibility of an exception in the “gravest and most important cases.” United States v. Reid, supra, at 366; McDonald v. Pless, supra, at 269. …
(c) The imperative to purge racial prejudice from the administration of justice was given new force and direction by the ratification of the Civil War Amendments. “[T]he central purpose of the Fourteenth Amendment was to eliminate racial discrimination emanating from official sources in the States.” McLaughlin v. Florida, 379 U. S. 184, 192. …
(d) This case lies at the intersection of the Court’s decisions endorsing the no-impeachment rule and those seeking to eliminate racial bias in the jury system. …
(e) Before the no-impeachment bar can be set aside to allow further judicial inquiry, there must be a threshold showing that one or more jurors made statements exhibiting overt racial bias that cast serious doubt on the fairness and impartiality of the jury’s deliberations and resulting verdict. … Whether the threshold showing has been satisfied is committed to the substantial discretion of the trial court in light of all the circumstances, including the content and timing of the alleged statements and the reliability of the proffered evidence.
… The Court need not address what procedures a trial court must follow when confronted with a motion for a new trial based on juror testimony of racial bias or the appropriate standard for determining when such evidence is sufficient to require that the verdict be set aside and a new trial be granted. Standard and existing safeguards may also help prevent racial bias in jury deliberations, including careful voir dire and a trial court’s instructions to jurors about their duty to review the evidence, deliberate together, and reach a verdict in a fair and impartial way, free from bias of any kind. Pp. 17–21. 350 P. 3d 287, reversed and remanded.