In the case of United States v. Jenkins, 1974, the Supreme Court ruled on whether a defendant could be convicted for refusing to answer questions before a grand jury even after being granted immunity from prosecution. The defendant, Jenkins, had been summoned by a grand jury investigating possible violations of federal laws but refused to answer certain questions despite being given transactional immunity - meaning he couldn't be prosecuted based on his testimony. He was then charged and convicted with criminal contempt for this refusal. On appeal, the Supreme Court held that an individual cannot refuse to testify in front of a grand jury about their own criminal activities if they have been granted full transactional immunity under U.S law which is coextensive with constitutional privilege against self-incrimination; hence it does not violate Fifth Amendment rights. Therefore, Jenkins' conviction was upheld.

In the dissenting opinion for United States v. Jenkins, Justice Douglas argued that the majority's decision to allow a warrantless search of an individual's car based on probable cause was unconstitutional. He contended that this ruling violated the Fourth Amendment, which protects citizens from unreasonable searches and seizures without a judicially sanctioned warrant supported by probable cause. Douglas believed there were no exigent circumstances in this case justifying bypassing obtaining a warrant before conducting the search. He also criticized law enforcement’s reliance on anonymous tips as grounds for probable cause, arguing they are often unreliable and can lead to abuses of power if not corroborated with other evidence or information. In his view, upholding such practices would undermine civil liberties and erode public trust in law enforcement agencies.