In the 1948 case Humphrey, Warden v. Smith, the United States Supreme Court addressed an appeal from a prisoner who was convicted of first-degree murder and sentenced to death in California state court. The petitioner argued that his constitutional rights were violated because he was not allowed to present evidence of insanity at the time of his offense or at sentencing. However, this argument had been rejected by both trial and appellate courts in California on procedural grounds because it wasn't raised during trial proceedings as required under state law. The U.S Supreme Court dismissed the writ for certiorari (a request for judicial review) as improvidently granted. This means that after further consideration, they decided not to hear arguments or decide on this particular case after all - effectively leaving lower court decisions intact without setting any national precedent.

The dissenting opinion in the Humphrey v. Smith case argued that the majority's decision to grant habeas corpus relief was incorrect because it failed to consider whether or not there was a fair trial, which is an essential element of due process. The dissent emphasized that even if evidence had been obtained illegally, this did not necessarily mean that the defendant’s right to a fair trial had been violated. It also pointed out inconsistencies in how federal courts applied rules about admissibility of evidence and suggested these should be clarified for future cases. Furthermore, it expressed concern over potential implications of the ruling on law enforcement practices and procedures across states as well as its possible impact on public safety by potentially undermining police authority and effectiveness.