General Cases
- Attorney–Client Privilege: Confidential communications between a client and their attorney regarding a case are protected. This privilege does not apply if the communication is made in the presence of third parties, is public, or is intended to further a crime (e.g., planning a future illegal act). It extends to joint defendants.
- Terry v. Ohio (Terry Stop): Allows police to briefly detain and frisk an individual for weapons if there is reasonable suspicion that a crime has occurred.
- Salinas v. Texas: Remaining silent alone does not invoke the Fifth Amendment; a suspect must explicitly state they are exercising their right to remain silent to be protected.
- Pennsylvania v. Mimms: During a traffic stop, officers may order all vehicle occupants to exit and may conduct a pat-down.
- Miranda v. Arizona: Before custodial interrogation, suspects must be informed of their right to remain silent and their right to an attorney. Statements obtained without these warnings may be inadmissible in court.
- Gant v. Arizona: Police may search a vehicle after an occupant's arrest only if it is reasonable to believe evidence of that specific offense is inside.
- New York v. Belton: Following a lawful arrest of a vehicle occupant, police may search the passenger compartment. Searches are also permitted based on sensory detection (sight or smell) of illegal substances.
- South Dakota v. Opperman: Police may conduct an inventory search of any vehicle that is being lawfully impounded.
- Carroll v. United States: Vehicle searches are permitted if there is reasonable suspicion that evidence of an arrestable offense is inside.
- Michigan v. Long: Search of vehicle storage compartments is allowed if there is reasonable suspicion of evidence related to an arrestable offense.
- Chimel v. California: Arresting someone in their home does not grant officers the authority to conduct a warrantless search of the entire house.
- Horton v. California: Evidence in "plain view" may be seized by police without a warrant.
- Minnesota v. Dickerson: During a lawful pat-down for weapons, if an officer feels an item that is immediately identifiable as contraband, they may seize it.
- Heien v. North Carolina: An arrest or search based on a reasonable mistake of fact does not violate the Fourth Amendment.
- Arizona v. Johnson: During a lawful traffic stop, police may pat down passengers if they have reasonable suspicion the passengers are armed or dangerous.
- Brendlin v. California: During a traffic stop, all passengers are considered "seized" under the Fourth Amendment, not just the driver.
- Mapp v. Ohio: Established the "exclusionary rule," which prevents evidence obtained in violation of the Fourth Amendment from being used in court.
- Illinois v. Wardlow: Unprovoked flight from police in a high-crime area can provide the reasonable suspicion necessary for an investigatory detention and protective frisk.
- Fong Foo v. United States: The Fifth Amendment’s Double Jeopardy Clause prevents the government from retrying a defendant once they have been acquitted by a court with jurisdiction, regardless of whether the acquittal was based on a legal error.