In the 1952 case of Alison v. United States, the Supreme Court examined whether a defendant's right to due process was violated when they were not present at a hearing where their sentence was reduced. The petitioner, Mr. Alison, had been convicted and sentenced for mail fraud in absentia while he fled from authorities. After his capture and imprisonment, his original sentence was reduced by the trial judge without him being present or notified about this proceeding. The Supreme Court ruled that there had been no violation of due process rights as guaranteed by the Fifth Amendment because these rights are intended to protect defendants from harm rather than benefit them with leniency. The court reasoned that since Mr. Alison’s absence did not result in an increase in punishment but instead led to a reduction of his sentence, it could not be seen as prejudicial against him. Therefore, even though he wasn't given notice or allowed to participate in this post-trial proceeding which affected his liberty interests directly (his term of incarceration), it didn’t constitute any constitutional error under existing legal principles regarding procedural fairness and justice.

In the dissenting opinion for Alison v. United States, it was argued that the majority's decision to uphold a conviction based on evidence obtained through an unlawful search and seizure contradicted previous Supreme Court rulings. The dissenting justices believed that this case represented a significant departure from established Fourth Amendment jurisprudence, which protects individuals against unreasonable searches and seizures by government officials. They contended that allowing illegally obtained evidence to be used in court would undermine citizens' constitutional rights and incentivize law enforcement officers to disregard these protections in their investigations. Furthermore, they expressed concern about the potential implications of this ruling for future cases involving similar circumstances, fearing it could set a dangerous precedent where violations of constitutional rights are overlooked or ignored by courts.