---
title: "Fourth Amendment Search"
type: Legal Term
source: https://casebriefly.com/legal-terms/fourth-amendment-search
---

# Fourth Amendment Search

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.

## Related Terms

- fourth-amendment-seizure
- warrant-requirement
- exclusionary-rule-4th-am
- plain-view-doctrine

## Related Cases

- arizona-v-gant

## 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.

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Source: [Fourth Amendment Search — CaseBriefly](https://casebriefly.com/legal-terms/fourth-amendment-search)