Explain the fourth amendment

Answer 1

A large number of cases fit this description, since the Supreme Court has taken an active role in defining the limits of Fourth Amendment protection against illegal search and seizure. The following are a selection of 4th Amendment precedents:

Michigan Department of State Police v. Sitz, 496 US 444 (1990) upheld the use of sobriety traffic checkpoints; however, Indianapolis v. Edmond, 531 US 32 (2001) held that this rule does not extend to checkpoints designed to search for drugs, because the search is too generalized. In Edmund, the search was confined to the use of drug-sniffing dogs (which is legal if the car is lawfully stopped) and outside visual check.

Florida v. Bostick, 501 US 429 (1991) held that evidence obtained during random bus searches, if conduct with the passengers' consent (even if the passenger feels compelled by circumstances to agree), is not a violation of the Fourth Amendment prohibition against unreasonable search and seizure.

Florida v. Royer, 460 US 491 (1983) held that police cannot hold someone without probable cause, and any evidence found during the detention is obtained illegally and may not be used as evidence, even if the person appears to agree to the search.

Oliver v. United States, 466 US 170 (1984) held that open fields are not protected by the Fourth Amendment, even if they are fenced and marked with no trespassing signs.

Minnesota v. Dickerson, 508 US 366 (1993) held that drugs detected by touch during a routine patdown can be used as evidence, but only if they were found in an area that might logically conceal a weapon.

Ohio v. Robinette, 519 US 33 (1996) held that a lawfully detained defendant does not need to be told explicitly that he or she is "free to go" before they can voluntarily agree to a search and seizure. Conviction on drug charges also upheld, despite defendant being stopped for another cause (speeding).

Illinois v. Caballes, 543 US 405 (2005) held that drug-sniffing dogs may be used during routine traffic stops (but not at checkpoints).

Bond v. United States, 529 US 334 (2000) held that a person has a legal expectation of privacy if their luggage is stored in a compartment (referring to a bus or other public transportation), and that any police manipulation of that luggage constitutes illegal search and seizure.

New York v. Belton, 453 US 454 (1981) held that police can search the passenger compartment of a stopped car and any containers found inside it as part of the valid arrest of any of the vehicle's occupants.

Pennsylvania v. LaBron, 518 US 938 (1993) held that police do not need to obtain a search warrant for a vehicle if the vehicle is capable of leaving the scene, even if there is time to obtain a search warrant.

Wyoming v. Houghton, 526 US 295 (1999) held that police can search a passenger's belongings inside a car if they already have probable cause to search the car.

Thornton v. United States, 541 US 615 (2004) held that police may search the passenger compartment of a suspect's car, even if their first contact with the person occurs after he or she leaves the car.

California v. Acevedo, 500 US 565 (1991) held that police can conduct a warrantless search of a paper bag in the trunk of a car if they have probable cause to believe the bag contains drugs.

California v. Carney, 471 US 386 (1985) held that police can conduct a warrantless search of a motor home (RV) if they have probable cause.

United States v. Villamonte-Marquez, 462 US 579 (1983) held that customs officials may conduct warrantless searches of boats pursuant to Title 19 USC §1581(a).

California v. Ciraolo, 476 US 207 (1986) held that police may take unaided aerial photographs of the area immediately surrounding a home using a private plane or helicopter as long as they are in public airspace.

Florida v. Riley, 488 US 445 (1989) held that police do not need a warrant to observe an individual's property from public airspace.

Arizona v. Gant, (slip opinion) (2008) held that police may search the passenger compartment of a vehicle incident to arrest, and without a warrant, only if it is reasonable to believe that the arrestee might access the vehicle at the time of the search, or if the vehicle contains evidence of the offense of arrest. (Compare with the decision in Belton; Gant narrows the exception).

Kyllo v. United States, 533 US 27 (2001) held that use of a thermal imaging device to detect grow lights being used inside a house for cultivating marijuana is a Fourth Amendment violation and requires a warrant.

Alabama v. White, 496 US 325 (1990) held that an anonymous tip as corroborated by independent investigation, is sufficient to provide reasonable suspicion to make an investigative stop.

Whren v. United States, 517 US 806 (1996) upheld the conviction on drug possession charges of two individuals who were pulled over because police became suspicious when they sat too long at a stoplight. Defendants claimed there was no probable cause to stop them. The Court ruled that the temporary detention of a motorist does not violate the Fourth Amendment prohibition against unreasonable seizure, "even if a reasonable officer would not have stopped the motorist absent some additional law enforcement objective."

Colorado v. Bertin, 479 US 367 (1987) held that contraband discovered in the process of inventorying an impounded car is lawful, and the items can be used as evidence in court.

Murray v. United States, 487 US 533 (1988) FDA agents observed suspicious activity occurring in and around a warehouse, with numerous vehicles driving into the warehouse and exiting a few minutes later. Two vehicles were stopped and the occupants were arrested for marijuana possession. After everyone left the warehouse, the DEA agents broke in, observed 270 bales of marijuana, then left to obtain a search warrant. They did not inform the magistrate of the break-in when requesting the warrant. The lower courts hed the warrant was invalid because the agents hadn't been forthcoming about entering the building prior to requesting the warrant. The Supreme Court reversed, holding the Fourth Amendment does not preclude admission of evidence discovered in an illegal, warrantless search if the same evidence is discovered later using a warrant.

New Jersey v. T.L.O., 469 US 325 (1985) held that public school searches do not require warrants as long as there is reasonable cause tot suspect illegal activity of the presence of contraband.

Illinois v. Gates, 462 US 213 (1983) overturned the landmark decisions in Aguilar v. Texas, (1964) and Spinelli v. United States, (1969), and replaced the Aguilar-Spinelli Test that gives little weight to confidential informant or anonymous tips when granting search warrants with a "totality of the circumstances" test.

United States v. Leon, 468 US 497 (1984) Established the "good faith" exception to the exclusionary rule that held evidence procured using defective warrants issued in error using insufficient probable clause could be used in court if the police had acted on the warrant in good faith (believed it was valid).

United States v. Santana, 427 US 38 (1976) held that a warrantless arrest inside the suspect's home was justified because the suspect was standing in a doorway when police approached. Since she was in full public view, she had no expectation of privacy. Retreating inside the house did not trigger Fourth Amendment protection because the arrest had been set in motion in a "public place."

Much of the case law permitting warrantless entry under exigent circumstances is determined by lower federal and state decisions, and is beyond the scope of discussion here, due to the level of expertise and detail involved in the explanation. The subject is discussed in detail in law enforcement training manuals.