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.
A search warrant is a court order that a magistrate or judge issues to authorize law enforcement officers to conduct a search of a person, location, or vehicle for evidence of a crime and to confiscate any evidence they find. In most countries, a search warrant cannot be issued in aid of civil process.
In United States criminal law, probable cause is the standard by which police authorities have reason to obtain a warrant for the arrest of a suspected criminal or the issuing of a search warrant. It is also the standard by which grand juries issue criminal indictments. The principle behind the standard is to limit the power of authorities to perform random or abusive searches, and to promote lawful evidence gathering and procedural form during criminal arrest and prosecution. The standard also applies to personal or property searches.
Search and seizure is a procedure used in many civil law and common law legal systems by which police or other authorities and their agents, who, suspecting that a crime has been committed, commence a search of a person's property and confiscate any relevant evidence found in connection to the crime.
New Jersey v. T.L.O., 469 U.S. 325 (1985), is a case in which the Supreme Court of the United States established the standard of reasonableness for searches of students conducted by public school officials in a school environment. The Court held that the Fourth Amendment to the U.S. Constitution, specifically its prohibition on unreasonable searches and seizures, applies to searches conducted by school officials. However, school officials do not need to have probable cause or obtain a warrant before searching a student. Instead, in order for a search to be justified, school officials must have reasonable suspicion that the student has violated either the law or school rules.
United States v. Ross, 456 U.S. 798 (1982), was a search and seizure case argued before the Supreme Court of the United States. The high court was asked to decide if a legal warrantless search of an automobile allows closed containers found in the vehicle to be searched as well. The appeals court had previously ruled that opening and searching the closed portable containers without a warrant was a violation of the Fourth Amendment, even though the warrantless vehicle search was permissible due to existing precedent.
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 decision expanded the Fourth Amendment's protections from the right of search and seizures of an individual's "persons, houses, papers, and effects", as specified in the U.S. Constitution, to include as a constitutionally protected area "what [a person] seeks to preserve as private, even in an area accessible to the public".
Section 8 of the Canadian Charter of Rights and Freedoms provides everyone in Canada with protection against unreasonable search and seizure. This right provides Canadians with their primary source of constitutionally enforced privacy rights against unreasonable intrusion from the state. Typically, this protects personal information that can be obtained through searching someone in pat-down, entering someone's property or surveillance.
Expectation of privacy is a legal test which is crucial in defining the scope of the applicability of the privacy protections of the Fourth Amendment to the United States Constitution. It is related to, but is not the same as, a right to privacy, a much broader concept which is found in many legal systems. Overall, expectations of privacy can be subjective or objective.
Illinois v. Caballes, 543 U.S. 405 (2005), was a United States Supreme Court case in which the Court held that the Fourth Amendment is not violated when the use of a drug-sniffing dog during a routine traffic stop does not unreasonably prolong the length of the stop.
R v Belnavis, [1997] 3 S.C.R. 341, is a leading Supreme Court of Canada decision on the right against unreasonable search and seizure under section 8 of the Canadian Charter of Rights and Freedoms. The Court held that there is no reasonable expectation of privacy in the backseat of a car.
United States v. Flores-Montano, 541 U.S. 149 (2004), was a United States Supreme Court case in which the Court held that customs agents may remove the gas tank from a vehicle crossing the international border in an effort to look for contraband.
In United States criminal law, the border search exception is a doctrine that allows searches and seizures at international borders and their functional equivalent without a warrant or probable cause. The doctrine is not regarded as an exception to the Fourth Amendment, but rather to its requirement for a warrant or probable cause. Balanced against the sovereign's interests at the border are the Fourth Amendment rights of entrants. Not only is the expectation of privacy less at the border than in the interior, the Fourth Amendment balance between the interests of the government and the privacy right of the individual is also struck much more favorably to the government at the border. This balance at international borders means that routine searches are "reasonable" there, and therefore do not violate the Fourth Amendment's proscription against "unreasonable searches and seizures".
Arizona v. Gant, 556 U.S. 332 (2009), was a United States Supreme Court decision holding that the Fourth Amendment to the United States Constitution requires law enforcement officers to demonstrate an actual and continuing threat to their safety posed by an arrestee, or a need to preserve evidence related to the crime of arrest from tampering by the arrestee, in order to justify a warrantless vehicular search incident to arrest conducted after the vehicle's recent occupants have been arrested and secured.
Almeida-Sanchez v. United States, 413 U.S. 266 (1973), was a United States Supreme Court case holding that the warrantless search of an automobile by the United States Border Patrol without a warrant or probable cause violates the Fourth Amendment. The vehicle was stopped and searched for illegal aliens twenty-five miles (40 km) from the Mexican border. The Court approached the search from four views: automobile search, administrative inspection, heavily regulated industry inspection, and border search. As to the validity of the search under the automobile exception, the Court found no justification for the search under the Carroll doctrine because there was no probable cause. As to the validity of the search under various administrative inspection doctrines, the Court found that the officers lacked an area warrant. As to the validity of the heavily regulated industry inspection, the Court found that the doctrine is not applicable to traveling on a state highway. As to the validity of a border search, the Court found that the site of the stop and the entirety of the road on which the stop occurred was too far from the border to be considered a border search.
O'Connor v. Ortega, 480 U.S. 709 (1987), is a United States Supreme Court decision on the Fourth Amendment rights of government employees with regard to administrative searches in the workplace, during investigations by supervisors for violations of employee policy rather than by law enforcement for criminal offenses. It was brought by Magno Ortega, a doctor at a California state hospital after his supervisors found allegedly inculpatory evidence in his office while he was on administrative leave pending an investigation of alleged misconduct. Some of what they uncovered was later used to impeach a witness who testified on his behalf at the hearing where he unsuccessfully appealed his dismissal.
United States v. Jones, 565 U.S. 400 (2012), was a landmark United States Supreme Court case which held that installing a Global Positioning System (GPS) tracking device on a vehicle and using the device to monitor the vehicle's movements constitutes a search under the Fourth Amendment.
Soldal v. Cook County, 506 U.S. 56 (1992), was a United States Supreme Court case in which the Court held that a seizure of property like that which occurs during an eviction, even absent a search or an arrest, implicates the Fourth Amendment. The Court also held that the Amendment protects property as well as privacy interests, in both criminal as well as civil contexts. Finally, saying that "certain wrongs affect more than a single right", the Court left open the possibility that the Fourteenth Amendment's protections against deprivation of property without due process of law may also be implicated.
A minimally intrusive/invasive warrantless search is a type of search that does not breach the boundaries of the property and is performed without any prerequisite search warrant. These searches are contested regularly in courts, and have been ruled for and against under different circumstances. The primary debate concerns the method in which the search is conducted, and also the area being searched. Issues concerning warrantless search and subsequent seizure are always of local concern, because they are a community law enforcement issue as well as a national law issue.
Byrd v. United States, 584 U.S. ___ (2018), was a US Supreme Court case that held that drivers of rental cars have rights protecting them from unconstitutional searches by police, even if the drivers are not listed on the rental agreement.
