In the 1993 case Clarence Victor v. Nebraska, the U.S. Supreme Court examined whether jury instructions given in two separate murder trials violated the defendants' rights to due process by misstating or inadequately explaining reasonable doubt standards. The court held that while some of the language used in both sets of instructions was problematic, it did not rise to a level of constitutional violation because each instruction as a whole conveyed an accurate understanding of reasonable doubt. Clarence Victor had been convicted for first-degree murder and sentenced to death based on circumstantial evidence. He argued that his conviction should be overturned because jurors were told they could find him guilty if they believed his guilt was "very probable." The high court disagreed with this argument, stating that although using terms like "very probable" might confuse jurors about what standard is required for conviction, other parts of the jury's instructions made clear that guilt must be found beyond a reasonable doubt.

In the dissenting opinion for Clarence Victor v. Nebraska, Justice Blackmun argued that the jury instructions given in both cases were constitutionally inadequate because they failed to convey properly the concept of reasonable doubt. He believed that these instructions allowed jurors to convict based on a degree of proof below what is required by due process and thus violated defendants' rights. Additionally, he criticized the majority's decision as it seemed to retreat from previous rulings which emphasized that conveying the idea of reasonable doubt is crucial in criminal trials. Furthermore, Justice Blackmun expressed concern over how this ruling could affect future cases where juries are not adequately instructed about reasonable doubt - potentially leading to wrongful convictions or undermining public confidence in judicial proceedings.