Fourth amendment

fourth amendment: an overview

The Fourth Amendment of the U.S. Constitution provides, "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." Ultimately, these words endeavor to protect two fundamental liberty interests - the right to privacy and freedom from arbitrary invasions.

A search occurs when an expectation of privacy that society considers reasonable is infringed by a governmental employee or by an agent of the government. Private individuals who are not acting in either capacity are exempt from the Fourth Amendment prohibitions.

A seizure refers to the interference with an individual's possessory interest in property. To meet the definition of an unreasonable seizure, the property's owner must have had a reasonable expectation of privacy in the items seized. A person is seized when law enforcement personnel use physical force to restrain the person if a reasonable person in the same or a similar situation would not feel free to leave the situation. The previous owner of abandoned property cannot allege an unreasonable seizure of that abandoned property. Abandoned property is property left behind by its owner in a manner in which the owner abandons the possessory interest in the property and no longer retains a reasonable expectation of privacy with regard to the search.

The prohibition on unreasonable searches and seizures particularly affects the work of law enforcement personnel by restricting the actions that they may take in performing a criminal investigation; however, the ban also disallows unreasonable searches and seizures in the civil litigation context. Law enforcement may only conduct a search if individualized suspicion motivates the search. The Fourth Amendment prohibits generalized searches, unless extraordinary circumstances place the general public in danger.

To sue regarding an alleged Fourth Amendment violation, the plaintiff must have standing. Standing with respect to Fourth Amendment violations requires that the plaintiff have had a legitimate expectation of privacy at the searched location. A legitimate expectation of privacy must meet both the subjective and objective tests of reasonableness. The subjective test requires that the plaintiff actually and genuinely expected privacy, and the objective test requires that given the circumstances, a reasonable person in the same or a similar situation would have expected privacy as well.

The Fourteenth Amendment of the U.S. Constitution applies the Fourth Amendment's provisions against the states as well as the federal government. See Mapp v. Ohio, 367 U.S. 643 (1961).

The Exclusionary Rule

Courts ordinarily suppress evidence obtained during an unreasonable search or seizure and offered against the accused. See Mapp v. Ohio, 367 U.S. 643 (1961). This rule, known as the exclusionary rule, applies equally to both the investigatory and accusatory stages of a criminal prosecution.

The Warrant Requirement

In order to avoid illegally searching or seizing the property of a suspect, law enforcement personnel typically obtain search warrants. To obtain a search warrant, law enforcement must show probable cause, must support the showing by oath or affirmation, and must describe in particularity the place they will search and the items they will seize. A judge can find probable cause only be examining the totality of the circumstances.

Different types of warrants exist. A knock-and-announce warrant requires law enforcement personnel to knock on the door of a residence and announce their identity before entering, giving the owner or occupier an opportunity to answer the door. In 2006, the U.S. Supreme Court determined that law enforcement's failure to knock or announce when in possession of a knock-and-announce warrant does not necessitate use of the exclusionary rule. See Hudson v. Michigan, 547 U.S. 586 (2006).

No-knock warrants allow law enforcement personnel to enter a building or home without announcing their presence and without knocking on the door first. Courts reserve these warrants for situations in which a building's owner or occupier could destroy the sought-after evidence by the time law enforcement waits for the owner or occupier to open the door.

An anticipatory warrant grants police officers a warrant that becomes valid after some future triggering condition occurs. Courts reserve these types of warrants for situations in which police have probable cause that at some future time evidence in a particular location will become available. Although United States v. Grubbs presented a challenge to the constitutionality of this type of warrant, the U.S. Supreme Court found that anticipatory warrants do not violate the Fourth Amendment's Warrant Clause. 547 U.S. 90 (2006).

Exceptions to the Warrant Requirement

Exceptions to the warrant requirement exist, however. The plain view doctrine is one exception. Pursuant to the plain view doctrine, if a government agent takes possession of property not included within the warrant but that was in the plain view of the government agent, then the property may be taken. A seizure of evidence in plain view does not compromise any further expectation of privacy than that already compromised by the warrant and thus serves as the rationale behind the plain view doctrine.

Officers can also search and seize objects on a person if the officer has placed the person under arrest. This exception extends to situations in which the police in good-faith mistakenly arrest the wrong suspect and seize contraband during the search. If a suspect, either during a traffic stop or otherwise, makes a furtive gesture, the gesture justifies a limited warrantless police intrusion.

At times exigent circumstances will make obtaining a warrant impractical. The law permits officers to make warrantless searches and seizures if they find that exigent circumstances exist and that they have probable cause. An exigent circumstance exists when an officer has a compelling need to take official action but lacks the time needed to acquire a warrant. Determining probable cause in this context requires a consideration of the totality of the circumstances to determine whether an officer acted in accord with a high probability that the search would turn up contraband or evidence. The decision maker must examine the facts making up the totality of the circumstances from the viewpoint of an objectively reasonable officer prior to making the arrest.

If officers enter a residence or building without a warrant to assist in an emergency, the entry does not violate the Fourth Amendment.

If the officer receives consent to make a search without a warrant, the search does not violate the Fourth Amendment. The consent must be given voluntarily, which means the giver must give it unequivocally, specifically, and intelligently. Consent must not have resulted from coercion or duress. Similarly, a third-person may give consent for law enforcement to search a house or premises if the third-person lawfully owns or occupies the premises. However, if two residents are present and one consents but the other objects, the rights of the objecting party override the other party's consent. See Georgia v. Randolph, 547 U.S. 103 (2006). Police can then use any evidence or contraband obtained against another person who resides in the residence or on the premises but did not give consent. Employers can consent to a police search of areas within its building, excluding areas specifically assigned to an employee at a place of business. Landlords cannot permit the search of a leased premises.

The law treats staff and faculty members of public educational insitutions as agents of the government. Therefore, the Fourth Amendment applies to public school employees, but a less stringent standard prevails. In the context of public school searches, employees may perform a search on the condition that they have reasonable suspicion. Reasonable suspicion requires a rational basis upon which to believe that a student possesses contraband or has committed a crime. Hunches, rumors, or guesses do not constitute reasonable suspicion.

Searches made at or near the border are also exempt from warrant requirements.

Electronic Searches and Seizures

The interplay between the Fourth Amendment and electronic searches and seizures has received much attention from the courts in recent years. With the advent of the internet and increased popularity of computers, law enforcement has witnessed a continually increasing amount of crime occurring electronically. Consequently, evidence of such crime can often be found on computers, hard drives, or other electronic devices. Yet, the parameters of the Fourth Amendment do not cease in the realm of searching electronic devices.

Many electronic search cases have involved whether law enforcement can search the company-owned computer that an employee uses to conduct business. Although the case law is split, the majority holds that employees do not have legitimate expectations of privacy with regard to information stored on company-owned computers.  In the 2010 case of City of Ontario v. Quon (08-1332), the Supreme Court extended this lack of an expectation of privacy to text messages sent and received on a public employer-owned pager.

Electronic surveillance and wiretapping has also caused a significant amount of Fourth Amendment litigation lately.


Following the September 11, 2001 attacks on the World Trade Center and the Pentagon, Congress and the President enacted legislation to strengthen the intelligence gathering community’s ability to combat domestic terrorism.  Entitled the USA Patriot Act, the legislation’s provisions aimed to increase the ability of law enforcement to search email and telephonic communications in addition to medical, financial, and library records. 

One provision permitted law enforcement to obtain access to tapping stored voicemails by obtaining a basic search warrant rather than a surveillance warrant.  Obtaining the former requires a much lower evidentiary showing.A highly-controversial provision of the Act included permission for law enforcement to use sneak-and-peak warrants.  A sneak-and-peak warrant is a warrant in which law enforcement can delay notifying the property owner about the warrant’s issuance.  In an Oregon federal district court case that drew national attention, Judge Ann Aiken struck down the use of sneak-and-peak warrants as unconstitutionally violative of the Fourth Amendment.  See 504 F.Supp.2d 1023 (D. Or. 2007).  

The Patriot Act also expanded the practice of using National Security Letters (NSL).  An NSL is an administrative subpoena that requires certain persons, groups, organizations, or companies to provide documents about certain persons.  These documents typically involve telephone, email, and financial records.  NSLs also carry a gag order, meaning the person or persons responsible for complying cannot mention the existence of the NSL.  Under Patriot Act provisions, law enforcement can use NSLs when investigating U.S. citizens, even when law enforcement does not think the individual under investigation has committed a crime.  The Department of Homeland security has used NSLs frequently since its inception.  By using an NSL, an agency has no responsibility to first obtain a warrant or court order before conducting its search of records. 

See constitutional amendment.