In the case of Warden, Maryland Penitentiary v. Hayden (1966), the U.S. Supreme Court ruled that evidence seized during a hot pursuit is admissible in court, even if it was not listed in a search warrant. The case involved an armed robbery suspect who had fled to his home where police followed without obtaining a warrant first. During their search for weapons and the suspect himself, they found clothing matching descriptions given by witnesses which were later used as evidence leading to his conviction. The defense argued this violated Fourth Amendment rights against unreasonable searches and seizures since these items weren't specified in any warrant; however, the Supreme Court disagreed stating that exigent circumstances justified immediate action from law enforcement officers due to potential danger posed by an armed criminal on loose.

In the dissenting opinion for Warden, Maryland Penitentiary v. Hayden, Justice John Marshall Harlan II argued that the majority's decision to allow evidence seized during a warrantless search was in violation of the Fourth Amendment. He contended that this ruling blurred the lines between permissible and impermissible searches without warrants under exigent circumstances. According to him, allowing such an exception would lead to potential abuses by law enforcement officers who might exploit these situations as pretexts for conducting otherwise illegal searches or seizures. Furthermore, he expressed concern about how this could affect citizens' privacy rights and protections against unreasonable government intrusions into their homes and personal effects.