In the case of DiBella v. United States, 1961, the U.S. Supreme Court ruled that orders denying motions to return seized property are not final decisions and therefore cannot be appealed until after trial. The court held that such orders were only steps in the criminal case preliminary to a trial thereof and hence non-appealable as "final decisions" under section 1291 of Title 28 US Code which governs appeals from district courts. This decision was based on two consolidated cases where federal agents had seized items during illegal gambling raids without warrants, leading defendants to file motions for their return arguing they were unlawfully obtained evidence. In both instances, lower courts denied these motions but appellate courts reversed those rulings - prompting government's appeal to Supreme Court resulting in this landmark judgment.

In the dissenting opinion for Dibella v. United States, Justice Hugo Black argued that the majority's decision to deny a criminal defendant access to an appeal of a district court order denying his motion to suppress evidence was incorrect. He believed this denial violated the defendant's Fourth Amendment rights against unreasonable searches and seizures. According to Justice Black, if such orders are not immediately appealable, then defendants would be left with no remedy for violations of their constitutional rights until after they have been convicted based on potentially illegally obtained evidence - which he saw as too late in the process. Furthermore, he disagreed with the majority’s view that allowing immediate appeals would delay trials; instead arguing it could actually speed up proceedings by encouraging law enforcement officers and prosecutors to respect constitutional safeguards from outset.