In the case of Roger Keith Coleman v. Charles E. Thompson, Warden et al., 1991, the U.S Supreme Court was asked to consider whether a death row inmate could be executed if new evidence emerged after his trial that might prove his innocence. Coleman had been convicted and sentenced to death for rape and murder in Virginia but maintained his innocence throughout the process. After exhausting all appeals within the state system, he petitioned federal courts for habeas corpus relief based on newly discovered evidence suggesting another person may have committed the crimes. However, both district court and Fourth Circuit Court of Appeals denied him relief due to procedural default rule which states that claims not raised at state level cannot be considered in federal court unless there is cause shown for failure to raise them earlier along with actual prejudice resulting from alleged violation of law or constitution. The Supreme Court upheld these decisions by a vote of 6-3 stating that they lacked jurisdiction over such cases where petitioner failed to show cause for procedural default despite potential constitutional error at trial stage affecting judgment below.

In the dissenting opinion for Roger Keith Coleman v. Charles E. Thompson, Warden et al., Justice Blackmun argued that the majority's decision was a grave miscarriage of justice because it prioritized procedural rules over substantive fairness and accuracy in capital cases. He contended that Coleman should have been allowed to present his claims of innocence despite missing a filing deadline due to attorney negligence, as this case raised serious doubts about whether an innocent person might be executed. Blackmun criticized the majority for rigidly applying procedural bars without considering their potential impact on fundamental rights and principles such as ensuring fair trials and preventing wrongful convictions. He also expressed concern about how this ruling could undermine public confidence in the judicial system by appearing more concerned with technicalities than truth or justice.