Whether the Fourth Amendment applies to searches of students conducted by public-school officials.
Holding
Yes. Public-school officials are state actors, and their searches of students must satisfy the Fourth Amendment's prohibition on unreasonable searches and seizures.
Reasoning
The Fourth Amendment, incorporated against the States through the Fourteenth Amendment, restrains governmental action generally, not only police work. The Court had already applied the Amendment to non-law-enforcement officials, including building inspectors, workplace inspectors, and firefighters. A student's privacy interest is invaded by an arbitrary governmental search regardless of whether the official is investigating a crime or enforcing a regulatory rule.
School officials do not act merely as private parental delegates when they search students. Modern public schools exercise authority under compulsory-education laws and publicly mandated disciplinary policies. Because school authorities are state actors for First Amendment and due-process purposes, they likewise must respect Fourth Amendment limits when carrying out disciplinary searches.
Students retain legitimate privacy interests in personal effects brought to school, including purses, wallets, letters, photographs, money, and other private items. Although schools require substantial supervision and discipline, the Court refused to equate schoolchildren with prisoners or to conclude that students surrender all privacy simply by entering school grounds.