In the 1970 case Bruno v. Pennsylvania, the U.S Supreme Court ruled in favor of Joseph Bruno, who was convicted for murder by a jury that included an individual who had previously expressed a belief in his guilt. The court held that this violated Bruno's Sixth Amendment right to an impartial jury trial and Fourteenth Amendment due process rights. The juror had stated during voir dire (the preliminary examination of prospective jurors) that he believed Bruno was guilty based on media coverage but would try to remain unbiased. Despite this statement, he was not removed from the jury pool and later participated in convicting Bruno. In its decision, the Supreme Court emphasized that even if a biased juror promises to set aside their preconceived notions about a defendant’s guilt or innocence and judge solely based on evidence presented at trial, they should still be disqualified from serving because their bias could subconsciously influence their judgment.

In the dissenting opinion for Bruno v. Pennsylvania, the justice argued that the majority's decision to overturn Bruno's conviction was based on a misinterpretation of both state law and previous Supreme Court rulings. The justice contended that there was no constitutional violation in this case because Pennsylvania law does not require unanimity among jurors in order to convict someone of first-degree murder. Furthermore, they pointed out that prior Supreme Court decisions have upheld non-unanimous jury verdicts as long as at least nine jurors agreed on guilt beyond a reasonable doubt. Therefore, according to the dissenting opinion, it was inappropriate for the court to intervene and reverse Bruno’s conviction simply because one juror had doubts about his guilt.