In Leonard v. United States (1928), the Supreme Court ruled on a case involving the seizure of alcohol during Prohibition. The defendant, Leonard, was convicted for possessing and transporting liquor in violation of the National Prohibition Act after federal agents seized 80 cases from his premises without a warrant. On appeal, he argued that this constituted an unlawful search and seizure under the Fourth Amendment. However, the Supreme Court upheld his conviction by affirming that officers did not need a warrant to seize contraband goods in plain view if they were lawfully present at the location where they saw them - even if their presence was due to an illegal entry or trespass. This decision effectively expanded police powers while limiting individual privacy rights during Prohibition.

In the dissenting opinion for Leonard v. United States, Justice Oliver Wendell Holmes argued that the defendant's conviction should be overturned because he was not given a fair trial. He believed that the judge had improperly influenced the jury by instructing them to consider only whether or not Leonard had committed perjury, rather than allowing them to determine if there was reasonable doubt about his guilt. Furthermore, Holmes felt that it was unjust for Leonard to be convicted based on evidence obtained through an illegal search and seizure of his property. He maintained that such actions violated Leonard's Fourth Amendment rights and set a dangerous precedent for future cases involving similar circumstances.