Fourth Amendment (Search & Seizure)
The Fourth Amendment protects individuals from unreasonable searches and seizures by the government, generally requiring a warrant supported by probable cause, with evidence obtained in violation subject to the exclusionary rule.
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Exam Tip
Fourth Amendment = Search requires warrant OR exception. Know exceptions: SILA, automobile, plain view, consent, exigent, Terry. Katz = reasonable expectation of privacy.
What is the Fourth Amendment?
The Fourth Amendment protects "the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures."
Core Concepts
| Concept | Definition |
|---|---|
| Search | Government conduct violating reasonable expectation of privacy or physical trespass |
| Seizure | Meaningful interference with possessory interest |
| Probable Cause | Fair probability evidence will be found |
Warrant Exceptions
| Exception | Description |
|---|---|
| Search Incident to Arrest | Area within immediate control |
| Automobile | Vehicle with probable cause |
| Plain View | Officer lawfully present |
| Consent | Voluntary consent |
| Exigent Circumstances | Hot pursuit, destruction of evidence |
| Terry Stop | Reasonable suspicion |
Landmark Cases
- Katz v. United States (1967): Reasonable expectation of privacy
- Terry v. Ohio (1968): Stop and frisk
- Mapp v. Ohio (1961): Exclusionary rule applies to states
- Riley v. California (2014): Cell phone search requires warrant