The Fourth Amendment to the United States Constitution is part of the Bill of Rights. It prohibits unreasonable searches and seizures. In addition, it sets requirements for issuing warrants: warrants must be issued by a judge or magistrate, justified by probable cause, supported by oath or affirmation, and must particularly describe the place to be searched and the persons or things to be seized.
Mapp v. Ohio, 367 U.S. 643 (1961), was a landmark decision of the U.S. Supreme Court in which the Court ruled that the exclusionary rule, which prevents prosecutors from using evidence in court that was obtained by violating the Fourth Amendment to the U.S. Constitution, applies not only to the federal government but also to the U.S. state governments. The Supreme Court accomplished this by use of a principle known as selective incorporation; in Mapp this involved the incorporation of the provisions, as interpreted by the Court, of the Fourth Amendment which is applicable only to actions of the federal government into the Fourteenth Amendment's due process clause which is applicable to actions of the states.
In the United States, the exclusionary rule is a legal rule, based on constitutional law, that prevents evidence collected or analyzed in violation of the defendant's constitutional rights from being used in a court of law. This may be considered an example of a prophylactic rule formulated by the judiciary in order to protect a constitutional right. The exclusionary rule may also, in some circumstances at least, be considered to follow directly from the constitutional language, such as the Fifth Amendment's command that no person "shall be compelled in any criminal case to be a witness against himself" and that no person "shall be deprived of life, liberty or property without due process of law."
Wolf v. Colorado, 338 U.S. 25 (1949), was a United States Supreme Court case in which the Court held 6—3 that, while the Fourth Amendment was applicable to the states, the exclusionary rule was not a necessary ingredient of the Fourth Amendment's right against warrantless and unreasonable searches and seizures. In Weeks v. United States, 232 U.S. 383 (1914), the Court held that as a matter of judicial implication the exclusionary rule was enforceable in federal courts but not derived from the explicit requirements of the Fourth Amendment. The Wolf Court decided not to incorporate the exclusionary rule as part of the Fourteenth Amendment in large part because the states which had rejected the Weeks Doctrine had not left the right to privacy without other means of protection. However, because most of the states' rules proved to be ineffective in deterrence, the Court overruled Wolf in Mapp v. Ohio, 367 U.S. 643 (1961). That landmark case made history as the exclusionary rule enforceable against the states through the Due Process clause of the Fourteenth Amendment to the same extent that it applied against the federal government.
The open-fields doctrine, in the U.S. law of criminal procedure, is the legal doctrine that a "warrantless search of the area outside a property owner's curtilage" does not violate the Fourth Amendment to the United States Constitution. However, "unless there is some other legal basis for the search," such a search "must exclude the home and any adjoining land that is within an enclosure or otherwise protected from public scrutiny."
Stanley v. Georgia, 394 U.S. 557 (1969), was a U.S. Supreme Court decision that helped to establish an implied "right to privacy" in U.S. law in the form of mere possession of obscene materials.
Katz v. United States, 389 U.S. 347 (1967), was a landmark decision of the U.S. Supreme Court in which the Court redefined what constitutes a "search" or "seizure" with regard to the protections of the Fourth Amendment to the U.S. Constitution. The ruling expanded the Fourth Amendment's protections from an individual's "persons, houses, papers, and effects", as specified in the Constitution's text, to include any areas where a person has a "reasonable expectation of privacy". The reasonable expectation of privacy standard, known as the Katz test, was formulated in a concurring opinion by Justice John Marshall Harlan II.
Olmstead v. United States, 277 U.S. 438 (1928), was a decision of the Supreme Court of the United States, on the matter of whether wiretapping of private telephone conversations, obtained by federal agents without a search warrant and subsequently used as evidence, constituted a violation of the target’s rights under the Fourth and Fifth Amendments. In a 5–4 decision, the Court held that the Constitutional rights of a wiretapping target have not been violated. This decision was overturned by Katz v. United States in 1967.
Hudson v. Michigan, 547 U.S. 586 (2006), is a United States Supreme Court case in which the Court held that a violation of the Fourth Amendment requirement that police officers knock, announce their presence, and wait a reasonable amount of time before entering a private residence does not require suppression of the evidence obtained in the ensuing search.
Inevitable discovery is a doctrine in United States criminal procedure that permits admission of evidence that was obtained through illegal means if it would "inevitably" have been obtained regardless of the illegality. It is one of several exceptions to the exclusionary rule, or the related fruit-of-the-poisonous tree doctrine, which prevent evidence collected in violation of a defendant's constitutional rights from being admitted in court.
Schmerber v. California, 384 U.S. 757 (1966), was a landmark United States Supreme Court case in which the Court clarified the application of the Fourth Amendment's protection against warrantless searches and the Fifth Amendment right against self-incrimination for searches that intrude into the human body. Until Schmerber, the Supreme Court had not yet clarified whether state police officers must procure a search warrant before taking blood samples from criminal suspects. Likewise, the Court had not yet clarified whether blood evidence taken against the wishes of a criminal suspect may be used against that suspect in the course of a criminal prosecution.
United States v. White, 401 U.S. 745 (1971), was a United States Supreme Court decision which held that recording conversations using concealed radio transmitters worn by informants does not violate the Fourth Amendment protection against unreasonable searches and seizures, and thus does not require a warrant.
Stoner v. California, 376 U.S. 483 (1964), is a United States Supreme Court decision involving the Fourth Amendment. It was a criminal case appealed from the California Courts of Appeal after the California Supreme Court denied review. The case extended the situations under which search warrants are required as they reversed a robbery conviction made on the basis of evidence obtained in violation of the holding.
United States v. Janis, 428 U.S. 433 (1976), was a Supreme Court Case that found Max Janis and Morris Levine guilty of illegal bookmaking activities in Los Angeles in a 5-3 ruling. The two were arrested for the crime in November 1968. Appealing on the grounds of unconstitutionally seized evidence, Janis and Levine were heard by the 9th Circuit Court of Appeals in 1973. The case was ultimately heard by the Supreme Court in 1975, and the two were found guilty in 1976. More importantly, the case established that the exclusionary rule does not apply to civil cases where evidence is unconstitutionally seized by a state officer but used by a federal institution.
Nix v. Williams, 467 U.S. 431 (1984), was a U.S. Supreme Court case that created an "inevitable discovery" exception to the exclusionary rule. The exclusionary rule makes most evidence gathered through violations of the Fourth Amendment to the United States Constitution, which protects against unreasonable search and seizure, inadmissible in criminal trials as "fruit of the poisonous tree". In Nix, the Court ruled that evidence that would inevitably have been discovered by law enforcement through legal means remained admissible.
Murray v. United States, 487 U.S. 533 (1988), was a United States Supreme Court decision that created the modern "independent source doctrine" exception to the exclusionary rule. The exclusionary rule makes most evidence gathered through violations of the Fourth Amendment to the United States Constitution inadmissible in criminal trials as "fruit of the poisonous tree". In Murray, the Court ruled that when officers conduct two searches, the first unlawful and the second lawful, evidence seized during the second search is admissible if the second search "is genuinely independent of [the] earlier one."
Breithaupt v. Abram, 352 U.S. 432 (1957), was a United States Supreme Court case in which the Court ruled that involuntary blood samples, taken by a skilled technician to determine intoxication, do not violate substantive due process under the Fourteenth Amendment of the United States Constitution. This case was only the second time the Court considered whether police could forcibly enter inside a suspect's body to extract evidence. Writing for a 6–3 majority, Justice Tom C. Clark argued that blood tests were necessary as a matter of public policy to ensure traffic safety on roads and highways, and that "modern community living requires modern scientific methods of crime detection." Chief Justice Earl Warren and Justice William O. Douglas both wrote dissenting opinions in which they argued that the involuntary blood sample taken in this case was "repulsive" and violated substantive due process.
Lange v. California, 594 U.S. ___ (2021), was a United States Supreme Court case involving the exigent circumstances requirement related to the Fourth Amendment to the United States Constitution. The Court ruled unanimously that the warrantless entry into a home by police in pursuit of a misdemeanant is not unequivocally justified.
Stone v. Powell, 428 U.S. 465 (1976), was decision of the Supreme Court of the United States that limited which claims of Fourth Amendment violations could be made by state prisoners in habeas corpus petitions in federal courts. Specifically, a claim that the exclusionary rule had been broken would be barred if state courts had already given it a full and fair hearing. The decision combined two cases that were argued before the Supreme Court on the same day with similar issues, one filed by Lloyd Powell and the other, titled Wolff v. Rice, filed by David Rice.
A grant of appellate review is dismissed as improvidently granted when a court with discretionary appellate jurisdiction later decides that it should not review the case. Notably, the Supreme Court of the United States occasionally grants a petition of the writ of certiorari, only to later DIG the case.
