Fourth Amendment of the Constitution of the United States protects citizens from unreasonable searches and seizures by government officials. The amendment was the 4th of 10 additions made to the Constitution as part of the Bill of Rights , which guarantees fundamental rights and freedoms to every citizen.
The Fourth Amendment states, “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
The Bill of Rights.
The U.S. Constitution went into effect on June 21, 1788. Some states had refused to approve the Constitution unless a bill of rights was added. Supporters of the Constitution, known as Federalists, promised to support constitutional amendments that protected individual liberties against possible unjust rule by the national government. Congress proposed the first 10 amendments—the Bill of Rights—in 1789. The states ratified (approved) them in 1791.
Protections and limits.
The Fourth Amendment ensures that government authorities must act reasonably whenever they search a person or his or her home. The police must have probable cause to search, seize goods, or arrest people. Probable cause means that the police must have a good reason for assuming that they will find sufficient evidence of a crime. The Fourth Amendment requires that in most cases the authorities obtain a search or arrest warrant from a judge by showing the need for it. If a warrant cannot be obtained, the search or arrest is permitted only if the state’s need for evidence outweighs the individual’s right of privacy . In addition, the search or arrest may not be carried out in an unreasonable manner.
Home searches without a warrant are presumptively (considered to be) unreasonable unless the police officer has been given consent to the search or the search is incident to arrest—that is, during or immediately after an arrest is being made. A warrant is also not required if the item is in plain view or if there is probable cause to search and incident circumstances—that is, the officer did not have time to secure a warrant.
Under some circumstances, the police need only show that they have a “reasonable suspicion,” not probable cause, to conduct a search. The Fourth Amendment only requires a police officer to have a reasonable suspicion to stop a suspicious person and make reasonable inquiries—including “pat down” searches for hidden weapons—to confirm or deny that suspicion. A reasonable suspicion is also sufficient to justify a traffic stop, as well as a “pat down” of the driver and passengers in the car, if the officer believes that they were involved in criminal activity. If the traffic stop is valid and the action does not prolong the stop, the police do not need to provide a reasonable explanation to justify the use of a narcotics dog to walk around a car.
It does not violate the Fourth Amendment for the police to conduct traffic stops without any individualized suspicion, operate random sobriety checkpoints to identify drunk drivers, and conduct routine stops and searches at an international border.
If the police violate the Fourth Amendment while obtaining evidence in a criminal investigation, that evidence cannot be used in court during a criminal prosecution. Such evidence is considered “fruit of the poisonous tree.” The evidence is excluded from consideration, and the prosecutor must proceed without it. The exclusionary rule does not apply when police officers rely in good faith on an invalid warrant, when the evidence was also obtained from an independent source, and when it was apparent that the evidence would have eventually been discovered through legal means.
The Fourth Amendment presents special challenges to judges who must evaluate the constitutionality of the use of advanced technology such as thermal imaging, body scans, and GPS ( Global Positioning System ). Court rulings on the use of such technology focus on whether the technology invades a person’s reasonable expectation of privacy. Courts also have to consider how invasive the use of technology has to be to require a warrant.
History.
In 1761, James Otis of Boston failed to persuade the Superior Court of Massachusetts that writs of assistance violated “the fundamental principles of law.” The writs were general search warrants that did not name the place to be searched. The controversy over such writs led to the prohibition of general warrants in the Fourth Amendment.
In the case of Olmstead v. United States (1928), the Supreme Court of the United States ruled that government wiretapping does not violate the Fourth Amendment, unless, in placing the wiretap, officials trespass on private property. (Wiretapping is the process of intercepting information over telephone lines or other communication systems.) In two 1967 cases (Katz v. United States and Berger v. New York), however, the court placed limits on the government’s ability to use wiretaps.
In the 1961 case of Mapp v. Ohio, the Supreme Court of the United States ruled that prosecutors could not introduce into a trial evidence obtained without a search warrant, establishing the exclusionary rule. Since then, motions to suppress under the Fourth Amendment are perhaps the most common constitutional disputes in the U.S. court system.
