Fourth Amendment

1772First Notions Of Protection

In 1772, the first Committee of Correspondence is formed in Boston to write a declaration of colonists’ rights and a list of their grievances against Britain. Both documents mention protecting individuals against unreasonable search and seizure. Samuel Adams is the main author of the Rights of Colonists, which consists of three parts: the natural rights of colonists as men; the rights of the colonists as Christians; and the rights of the colonists as subjects (of the British crown). Dr. Joseph Warren produces a List of Infringements and Violations of Rights.

1791Bill Of Rights Ratified

By Dec. 15, three-fourths of the states ratify the Bill of Rights, the first 10 amendments to the Constitution. The amendments are meant to secure individual liberties and to maintain the balance of power between the federal government and the states. The 10th Amendment states that powers not delegated to the federal government belong to the states. Although not specified in the 10th Amendment, the U.S. Supreme Court rules in years to come that laws affecting family relations, commerce within a state’s borders, and local law enforcement fall within state authority.

1791Fourth Amendment Is Ratified

The Fourth Amendment is ratified as part of the Bill of Rights. The amendment protects citizens from unreasonable search and seizure by the government.

1921Court Allows Waiver Of Protections

In Amos v. U.S., the U.S. Supreme Court concludes that Fourth Amendment protections may be waived. This means that if a person consents to a search, he or she gives up the right to be free from an “unreasonable” search.

1949Court Rules Protections Apply To States

In Wolf v. Colorado, the U.S. Supreme Court finds that Fourth Amendment protections against unreasonable searches and seizures apply to officers of state governments (such as police officers or school officials), not just officers of the federal government.

1961Exclusionary Rule Is Created

In Mapp v. Ohio, the U.S. Supreme Court holds that evidence obtained in an illegal search and seizure is not admissible at trial. This principle is commonly known as the exclusionary rule.

1965Third Amendment Cited As Evidence Of Privacy Right

In Griswold v. Connecticut, the U.S. Supreme Court rules that the Constitution gives individuals a “zone of privacy” that includes the right of married couples to use birth control. The Court lists various constitutional provisions, including the Third, the Fourth and the Ninth Amendments, as evidence that the framers intended such a “zone of privacy” to exist.

1967Reasonable Expectation Of Privacy Concept Set

Explaining that the Fourth Amendment protects people, not places, the U.S. Supreme Court, in Katz v. U.S., prohibits electronic surveillance such as wiretapping without a warrant. The test for deciding whether Fourth Amendment protections apply is whether a person has a reasonable expectation of privacy under the circumstances.

1968Defendants Cannot Be Forced To Choose Between Rights

In Simmons v. United States, the U.S. Supreme Court rules that when a criminal defendant chooses to testify at a pretrial hearing about certain evidence (which the defendant alleges was gathered by police in violation of the Fourth Amendment’s search and seizure provision), that testimony – even if it is incriminating – cannot later be used against the defendant at trial. Otherwise, the court states, a defendant will be forced to choose between exercising his Fourth Amendment right (to try to suppress illegally obtained evidence) or his Fifth Amendment right (to refuse to give testimony against himself).

1968Reasonable Suspicion Overrides Absence Of Warrant

Whenever possible, the police should obtain a warrant before conducting a search of a person or a person’s property. In Terry v. Ohio, the U.S. Supreme Court recognizes an exception to the general rule and decides that the police may “pat down” the outside of a suspect’s clothing and search the immediate area for weapons when they have a “reasonable suspicion” of illegal activity.

1975Vehicle Stops Based Only On Occupants’ Appearance Unconstitutional

The U.S. Supreme Court says Border Patrol officers may not stop a vehicle solely because they suspect that it contains illegal immigrants. In U.S. v. Brignoni-Ponce, the justices unanimously decide that the challenged stop was unconstitutional because it was based on a single factor: The occupants appeared to be Mexican. The Court says that while this is a relevant factor, it cannot be the only factor in a vehicle stop.

1976Warrantless Arrest Based On Probable Cause Allowed

In U.S. v. Watson, the U.S. Supreme Court holds that the police may take a suspect into custody in a public place without an arrest warrant when there is “probable cause” to do so. Probable cause is based on anything that an officer observes or senses or on information provided by others.

1983Drug Seizure Upheld Under ‘Open Field’ Doctrine

In Oliver v. United States, the U.S. Supreme Court upholds the conviction of a Kentucky man for manufacturing a controlled substance, based on the police’s discovery of a field of marijuana a mile from his home. The Court rejects the defendant’s argument that the evidence should have been excluded at trial – because the police did not have a warrant, and because the man had posted “No Trespassing” signs around his property. The Court says the field qualifies as an “open field” in which the man could not have had a legitimate expectation of privacy. Consequently, a warrant was not needed, and the search and seizure of the evidence were proper under the Fourth Amendment.

1984Evidence Allowed Under ‘Good Faith’ Exception

A “good faith” exception to the exclusionary rule is recognized in U.S. v. Leon, allowing the police to use evidence that was obtained with a warrant later found to have been invalid. The exclusionary rule says that illegally seized evidence cannot be introduced at criminal trials.

1985Reasonableness Standard Cited In School Searches

After a student is caught smoking in her high school restroom, her purse is searched by an assistant vice principal who finds evidence that the student is dealing marijuana. The student confesses but appeals her conviction, saying the search was illegal so the evidence was not admissible. In New Jersey v. T.L.O., the U.S. Supreme Court says that the Fourth Amendment applies to public school officials but that a less strict standard applies. Instead of probable cause, school officials may conduct searches based on reasonable suspicion that school rules are being violated. The search must be limited to confirming that suspicion. The Court rules the search of the student’s purse did not violate the Fourth Amendment.

1986Aerial Surveillance For Drugs Ruled Constitutional

A police officer, acting on a tip but without a warrant, flies a plane over the backyard of a suspected marijuana dealer. He observes marijuana plants in the yard and obtains a search warrant for the property (attaching his pictures of the yard as evidence). After the homeowner fails to get the evidence excluded, claiming that the aerial surveillance violated the Fourth Amendment, he pleads guilty. The U.S. Supreme Court in California v. Ciraolo refuses to find the aerial surveillance to be an illegal search, even though the homeowner had built a 10-foot fence to maintain his privacy. The court finds that he had no reasonable expectation of privacy when the yard remained “knowingly exposed” to observation by the naked eye from the air.

1989Drug Tests For Jobs Associated With Security Risks Allowed

In National Treasury Employees Union v. Von Raab, the U.S. Supreme Court allows the government to drug-test U.S. Customs Service employees who are applying for jobs involving interdiction of illegal drugs or possession of a gun. The safety and security risks associated with those jobs, the court reasons, make such searches “reasonable,” and thus permissible under the Fourth Amendment even without a suspicion of wrongdoing.

1989Mandatory Drug Tests Of Rail Workers In Accidents Upheld

In another case involving drug tests in the workplace, the U.S. Supreme Court in Skinner v. Railway Labor Executives Association upholds mandatory drug testing of railroad employees after they are involved in an accident. The Court cites public safety concerns as its reason for concluding that such testing is a “reasonable” search under the Fourth Amendment.

1995Random Drug Testing Of Student Athletes Constitutional

In Vernonia School District v. Acton, the U.S. Supreme Court finds that the Fourth Amendment is not violated by a school district’s policy that students participating in interscholastic sports must consent to random drug testing. The Court requires that the use of random drug testing requires a fact-specific balancing of a student’s privacy interests with the school’s legitimate interest in protecting students from harm during participation in sports.

2000Required Drug Testing Of Welfare Recipients Struck Down

A U.S. District Court judge declares that a Michigan law calling for the random, suspicion-less drug testing of welfare recipients amounts to an illegal search in violation of the Fourth Amendment. In 2003, the Sixth U.S. Circuit Court of Appeals will affirm the ruling.

2001Use Of Drug-Detection Technology Without Warrant Is Restricted

In Kyllo v. United States, the U.S. Supreme Court rules that the police’s use of a thermal-imaging device without a warrant to scan the outside of a house, in an effort to discover whether marijuana was growing inside, is an illegal search under the Fourth Amendment. The Court concludes that when the police “use a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion,” the homeowner retains his expectation of privacy and a warrant is needed for such a search.

2002Random Drug Tests Upheld For Students In Non-Athletic Activities

In Board of Education v. Earls, the U.S. Supreme Court expands its earlier ruling in Vernonia School District v. Acton and finds that an Oklahoma school district’s policy of random drug tests for student participants in non-athletic extracurricular activities also is permissible under the Fourth Amendment.

2006Justice Department Defends Domestic Surveillance

Amid much debate over the legality of the National Security Agency’s domestic surveillance program, the Justice Department releases an extensive legal analysis supporting President George W. Bush’s power to authorize the program. The analysis cites the Constitution, the Federalist Papers, the writings of previous Democratic and Republican presidents, and various scholarly papers and court cases. According to the analysis, the NSA program, which allows the president to order wiretaps on international calls and e-mails without a warrant, violates neither the 1978 law overseeing intelligence wiretaps nor the Fourth Amendment’s protection of unreasonable searches.

2006Court Limits ‘Valid Consent’ For Searches

When police have valid consent to search a house, neither a warrant nor probable cause is necessary. The consent must be given voluntarily. In the case Georgia v. Randolph, the U.S. Supreme Court determines whether police have valid consent needed to search a home when one occupant consents but another, who is also present, objects. The Court decides, 5-3, that police entry is unjustified. Chief Justice John G. Roberts Jr. writes a scathing dissent, arguing that consent to live with another person entails the risk that one’s confidence and privacy will be betrayed by that person.

2006Police No-Knock Entry Into House Is Constitutional

Police in Detroit obtained a search warrant to investigate the home of Booker Hudson. They announced their presence at his door, but failed to knock before entering. Once inside, they found a gun and drugs and, as a result, arrested Hudson. The Supreme Court decides, 5-4, in Hudson v. Michigan that the police entry was legal, albeit a “misstep.” Writing for the court, Justice Antonin Scalia argues that suppressing evidence is too high a price for the police to pay when they would have entered Hudson’s house regardless of whether they knocked.

2007Patriot Act Provisions Struck Down

After the 9/11 terrorist attacks, Congress and President George W. Bush enact the Patriot Act, which increases the authority of intelligence agencies to gather information through searches of e-mail and phone communications as well as medical, library and financial records of individuals. One provision allowed the use of sneak-and-peek warrants, which let law enforcement conduct secret searches with the purpose of gathering foreign intelligence. The target did not have to be notified, and probable cause for the search was not required. U.S. District Judge Ann Aiken in Oregon strikes down this provision as well as one that allows secret wiretaps as violating the Fourth Amendment in the case U.S. v. Mayfield. Brandon Mayfield had been falsely accused of involvement in the 2004 Madrid train bombings. The FBI secretly searched his house numerous times before his arrest.

2009Court Limits Police Search Of Cars

The U.S. Supreme Court rules in Arizona v. Gant that the Fourth Amendment’s protection against unreasonable search and seizure prevents police officers from searching the vehicle of a person who has been arrested except in two situations. Those circumstances are: If the person has access to the car and can reach a weapon or tamper with evidence or if the officer believes the car holds evidence related to the arrest. Before, police generally have understood that they were free to search the vehicles of people they had arrested. The majority opinion says the 1981 precedent New York v. Belton was applied too broadly.

2009Strip Search Of Student Ruled Unconstitutional

The U.S. Supreme Court decides that a 13-year-old Arizona girl’s Fourth Amendment right against unreasonable search and seizure was violated when she was subject to a full strip search at school because she was suspected of possessing prescription-strength ibuprofen against school policy. The majority opinion says in Safford Unified School District v. Redding that a school’s search for contraband must not be “excessively intrusive in light of the age and sex of the student and the nature of the infraction.”

2010Searches Allowed On Employer-Owned Electronic Devices

How the Fourth Amendment applies to electronic searches of computers and and other devices has increasingly come to the attention of the courts. Generally, courts have held that employees do not have the expectation of privacy in regard to information stored on employer-owned equipment. The U.S. Supreme Court, in City of Ontario v. Quon, extends this to text messages on an employer-owned pager.

2011Court Expands Warrantless Search By Police

The U.S. Supreme Court decides, 8-1, that police may break into a house or apartment if they suspect evidence is being destroyed. In Kentucky v. King, which involved a search for illegal drugs, the Court says that officers who heard sounds indicating that evidence was being hidden or destroyed and smelled marijuana could enter the house without a warrant.

2012Police Cannot Use GPS Device Without Search Warrant

In a unanimous decision, the U.S. Supreme Court rules that the installation of a tracking device on a suspect’s car without a search warrant is unconstitutional. The ruling says that use of the GPS device constituted a search and that police needed to have a warrant. The case raises the question of modern technology’s effect on the Fourth Amendment and a person’s reasonable expectation of privacy.

2013Police Can Collect DNA From Arrested Suspects

The U.S. Supreme Court in Maryland v. King, in a 5-4 vote, rules that the police practice of taking a DNA sample from anyone who is arrested for a serious crime does not violate the Fourth Amendment’s prohibition against unreasonable searches. Justice Anthony M. Kennedy, in the majority opinion, says that a DNA swab is similar to taking fingerprints and photographs of a suspect, “a legitimate police booking procedure that is reasonable under the Fourth Amendment.” Twenty-eight states and the federal government already follow the practice.

The dissenting justices warn that the ruling allows a major change in police powers and that the restriction to only “serious” crimes will eventually be dropped. Justice Antonin Scalia writes: “This will solve some extra crimes, to be sure. But so would taking your DNA when you fly on an airplane – surely the TSA must know the ‘identity’ of the flying public. For that matter, so would taking your children’s DNA when they start public school.”

2014Police Must Get Warrant For Cellphone Search

In a unanimous ruling in Riley v. California, the U.S. Supreme Court decides that police generally must obtain a warrant to search the cellphone of a suspect. The Court in the past had approved searching many objects found on a suspect. But a search of a cellphone is different, Chief Justice John G. Roberts Jr. says. “The term ‘cell phone’ is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone,” Roberts writes. “They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers.”

2015Extended Traffic Stops Ruled Unconstitutional

In a 6-3 ruling, the U.S. Supreme Court decides in Rodriguez v. United States that police officers may not prolong traffic stops to wait for drug-sniffing dogs to check the vehicle. Justice Ruth Bader Ginsburg writes that a “police stop exceeding the time needed to handle the matter for which the stop was made violates the Constitution’s shield against unreasonable seizures.”

2019Without Warrant, Police May Take Blood From Unconscious DUI Suspect

The U.S. Supreme Court says in a 5-4 ruling that law enforcement officers, without a search warrant, may order blood drawn from an unconscious person suspected of driving drunk or while under the influence of drugs. The Fourth Amendment generally requires police to get a warrant to draw blood. In Mitchell v. Wisconsin, the Court upholds a Wisconsin law that says people driving on a public road have implied consent to having their blood drawn. In previous Court rulings, the justices have said that a blood draw is a significant bodily intrusion into a person’s privacy.

2021Court Upholds Limit On Warrantless Searches

The U.S. Supreme Court rules unanimously in Caniglia v. Strom that police cannot enter a home to conduct a search for safety reasons without a warrant. Police in Rhode Island had entered a home to search for a gun belonging to a man who had agreed to seek a mental health evaluation. The man sued, saying that his Fourth Amendment right had been violated. The police said they were acting under one of their “community caretaking” functions that allows searches without a warrant. However, the Court said the “community caretaking exception” is a narrow one, stemming from a 1973 ruling in Cady v. Dombrowski that said police could search an impounded car for an unsecured firearm.

2021Court: Police Cannot Enter Home For Minor Crime Without Warrant

In a unanimous ruling, the U.S. Supreme Court decided in Lange v. California that police cannot always enter a home without a warrant when in “hot pursuit” of someone for a minor crime. The Court sent the case back to the lower court to decide if the police violated the rights of a California man by pursuing him into his garage for allegedly playing loud music while driving on a highway late at night. In the Court’s ruling, Justice Elena Kagan said police had no right to enter the man’s home without a warrant for such a trivial offense. The Supreme Court has long held that police may conduct a warrantless search when pursuing a fleeing felon