Fourth Amendment Search
What does "Fourth Amendment Search" mean in law?
A Fourth Amendment search occurs when the government intrudes upon an individual's reasonable expectation of privacy, as established by the two-part test in Katz v. United States (1967): the person must exhibit a subjective expectation of privacy, and that expectation must be one that society recognizes as objectively reasonable. The Supreme Court in United States v. Jones (2012) also revived the trespass-based approach, holding that a search occurs when the government physically intrudes on a constitutionally protected area (persons, houses, papers, effects) to obtain information. Understanding what constitutes a 'search' is the threshold question in any Fourth Amendment analysis, because if government conduct does not qualify as a search, no warrant or exception is required.
Definition
A Fourth Amendment search occurs when the government intrudes upon an individual's reasonable expectation of privacy, as established by the two-part test in Katz v. United States (1967): the person must exhibit a subjective expectation of privacy, and that expectation must be one that society recognizes as objectively reasonable. The Supreme Court in United States v. Jones (2012) also revived the trespass-based approach, holding that a search occurs when the government physically intrudes on a constitutionally protected area (persons, houses, papers, effects) to obtain information. Understanding what constitutes a 'search' is the threshold question in any Fourth Amendment analysis, because if government conduct does not qualify as a search, no warrant or exception is required.
Example
When police placed a GPS tracking device on a suspect's car and monitored his movements for 28 days, the court held this constituted a Fourth Amendment search because it involved a physical trespass on a constitutionally protected effect to gather information.