In 2004, police in Washington, D.C. suspected that Antoine Jones was a cocaine dealer. Lacking a valid warrant (their previous warrant had expired), the police installed a global positioning system (GPS) device to track Jones movement of his vehicle over the course of a month. As a result of the data generated by the GPS, the police were able to find a “stash house” with drugs and nearly $1 million in cash. That evidence was used to convict Jones in 2008. But that evidence was later thrown out when the Supreme Court unanimously ruled that the warrantless use of this 21st Century GPS technology violated an 18th Century legal rule (the Fourth Amendment). (U.S. v. Jones, No. 10-1259, 2012.) Welcome to one of America’s greatest legal inventions – the prohibition against unreasonable searches and seizures.
Antoine Jones owes his court victory to the Fourth Amendment, a rule that was created in response to abuses by the British government in colonial America. Prior to American independence, the British army, using a general warrant, could enter any house to search for and seize any untaxed goods. Smarting from this government intrusion into their daily life, the drafters of the U.S. Constitution decided that their new country would be free of this offensive behavior. So they drafted the Fourth Amendment, which 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.”
In other words, the Fourth Amendment provides that the government cannot unreasonably seize people or their property, and that the government must establish probable cause in order to make arrests or seize private property.
Under the Fourth Amendment, a police officer can:
In both cases, probable cause must exist to justify the arrest or search. Probable cause exists when enough reliable information exists to support a reasonable belief that a person has committed a crime. Probable cause is more than a hunch and it cannot be made under a pretext or a “hope” that the police will catch a criminal. Probable cause must be based on reliable information.
A warrant gives the police the authority to make arrests and search and seize property. As with all arrests and searches, a police officer needs probable cause to obtain a warrant. Before granting the warrant, a judge reviews written statements signed under oath to verify that probable cause exists. An arrest or search conducted under the authority of a warrant does not violate the Constitution unless the arrest or search goes beyond the boundaries of what is provided in the warrant. For example, if a search warrant is granted to search the suspect’s downtown office, that does not give the police the right to search the suspect’s suburban home, as well.
Warrantless arrests or searches are legal provided that probable cause exists and that the activity—in light of the individual’s expectation of privacy—was reasonable. For example, a person selling drugs in a public park cannot have a reasonable expectation of privacy. A warrantless arrest of this person on the spot, or a warrantless seizure of the drugs would be permissible because, obviously, possessing drugs in public creates a reasonable belief that the person has committed a crime (probable cause). (To read about an instance in which officers need neither a warrant nor probable cause, see Invalid Police Searches and the Good Faith Exception.)
In general, the following types of warrantless activity are permitted:
If a search is unreasonable (as in the case of Antoine Jones, discussed above), the evidence obtained as result of the search cannot be used against the defendant (known as the “exclusionary rule”). In addition, the defendant may have grounds to sue the police in civil court—a difficult proposition—in cases of false arrest or illegal searches.
Over the years, the exclusionary rule has been criticized and to some extent limited, because of concerns over public safety and that criminals are being set free as a result of police errors. The modern trend in past decades has been to give the police more latitude when making judgments. For example, police in many instances need only have a reasonable suspicion (a lower standard than probable cause) of criminal activity in order to detain and frisk an individual. And not even a reasonable suspicion is required for searches based upon sniffer dog responses (a sniffer dog detects drugs at an airport) or at sobriety checkpoints.