Warrantless Searches and Seizures

Reprinted from: Warrantless Searches and Seizures, 40 Georgetown Law Journal Annual Review of Criminal Procedure 44 (2011) (283 Footnotes Omitted)

Under the Fourth Amendment, every search or seizure by a government agent must be reasonable. In general, searches and seizures are unreasonable and invalid unless based on probable cause and executed pursuant to a warrant. However, certain kinds of searches and seizures are valid as exceptions to the probable cause and warrant requirements, including investigatory stops, investigatory detentions of property, warrantless arrests, searches incident to a valid arrest, seizures of items in plain view, searches and seizures justified by exigent circumstances, consensual searches, searches of vehicles, searches of containers, inventory searches, border searches, searches at sea, administrative searches, and searches in which the special needs of law enforcement make the probable cause and warrant requirements impracticable.

Investigatory Stops of Persons. Not all encounters between individuals and police are seizures governed by the Fourth Amendment. A seizure occurs when a reasonable person (1) would not feel “free to leave” or (2) would not feel “free to decline the officers' requests or otherwise terminate the encounter.” Investigatory stops--brief seizures by police officers-- are governed by the Fourth Amendment and are lawful when justified by “reasonable suspicion.” A lesser standard than probable cause, reasonable suspicion exists when an officer can “point to specific and articulable facts, which, taken together with rational inferences from those facts, reasonably warrant th[e] intrusion.” In adopting this formulation, the Supreme Court in Terry v. Ohio emphasized the importance of balancing “the need to search (or seize) against the invasion which the search (or seizure) entails” to determine whether a search or seizure is lawful. Under this balancing approach, important government interests can justify brief investigatory stops based on less than probable cause.

Law enforcement officers may initiate an investigatory stop if they have reasonable suspicion that a person is engaged in criminal activity. To determine whether reasonable suspicion existed at the time of the encounter, courts use a “totality of the circumstances” test. Inarticulable hunches or generalized suspicions are insufficient. Police may stop and question a person for a limited period of time when they reasonably suspect that person is engaged in criminal activity. The requirements for performing an investigatory frisk are discussed later in this Section.

Generally, investigatory stops are valid only if reasonable suspicion objectively exists. The subjective intentions of police are irrelevant to an evaluation of the constitutionality of an investigatory stop under the Fourth Amendment. The primary bases for reasonable suspicion are a police officer's personal observations and the officer's knowledge that a crime has been committed. Courts afford considerable deference to the observations and conclusions of the police, reasoning that an experienced officer can infer criminal activity from conduct that may seem innocuous to a lay observer. Although an officer may not base reasonable suspicion on isolated or minimal instances of innocent activity, several apparently innocent activities may cumulatively create the requisite reasonable suspicion.

Reliable information from a citizen informant may also create reasonable suspicion and justify an investigatory stop. Courts assess the reliability of an informant's tip on a sliding scale: greater corroboration is necessary to justify acting on a tip from an unknown informant or an informant of uncertain trustworthiness, while less corroboration will suffice if the information is from a known source or source that has proven trustworthy.

Generalized fear of criminal activity and the presence of a suspect in a high-crime neighborhood are factors that, standing alone, do not justify seizure. Courts may use these factors, however, in assessing the totality of circumstances surrounding a seizure. For example, a suspect's unprovoked flight upon seeing the police can justify a seizure when it occurs in a high-crime neighborhood. Generalized suspicion of criminal activity based solely on race does not justify a seizure.

The range of police activities permitted during an investigatory stop must be reasonably related to the circumstances that initially justified the stop. During a lawful investigatory stop, police may ask questions or request documents to establish a person's identity and to confirm or dispel suspicions of criminal activity. If reasonable suspicion does not exist, police may still order occupants out of a vehicle they have lawfully stopped. In addition to detentions that are justified in the absence of a warrant, a detention may be justified because a search warrant implicitly carries with it the limited authority to detain the occupants of the premises while the search is conducted.

When the police hold a suspect beyond the amount of time necessary to effectuate the purpose of the stop, the seizure becomes an arrest and must be supported by probable cause. The Supreme Court has declined to establish a bright-line rule to determine when an investigatory stop becomes an arrest. Instead, lower courts decide on a case-by-case basis whether an investigatory stop has become an arrest. In making such decisions, courts consider the diligence of police in resolving their reasonable suspicion as quickly as possible, the scope and nature of the restraints placed on an individual's liberty, and whether police transported the individual to another location. The mere existence of a less intrusive means of investigation does not make a detention unreasonable. When a detainee's own actions contribute to the duration of a stop, a longer detention may be reasonable.

Under Terry, a police officer who makes an investigatory stop may conduct a limited pat-down frisk of a suspect's outer clothing. The frisk may only be conducted if the officer has a reasonable belief that the detainee poses a threat to the officer's safety or the safety of others. The frisk must be limited in scope to a search for weapons and may not be used to search for evidence of criminal activity.

Investigatory Detentions of Property. Under the Fourth Amendment, seizures of property in which a person has a legitimate privacy interest are valid only when police reasonably suspect that the property constitutes evidence of criminal activity. Seizures of property that is abandoned, in plain view, or obtained by consent are valid because the Fourth Amendment does not protect voluntarily surrendered privacy interests. When evaluating the reasonableness of a seizure of property, courts consider the duration and intrusiveness of the seizure, including how quickly police conducted their investigation of the seized property and whether police took the seized property to a different location after seizing it. While brief seizures of property are valid if based on reasonable suspicion, a subsequent search of seized property is generally valid only if executed pursuant to a warrant issued upon probable cause.

Warrantless Arrests. In certain circumstances, a law enforcement officer may lawfully arrest a person without an arrest warrant. An officer may conduct a warrantless arrest if (1) the arrestee has committed an offense in the officer's presence, (2) the officer has probable cause to believe the arrestee has committed a felony and the arrest occurs in a public place, or (3) the officer has probable cause for an arrest and the circumstances are “exigent.” After making a warrantless arrest, an officer must promptly secure a judicial determination of probable cause. The probable cause required to make a lawful warrantless arrest is identical to the probable cause required to secure an arrest warrant.

Probable cause alone is insufficient to justify warrantless entry into a person's home and warrantless arrests in suspects' dwellings are presumptively unreasonable. Absent consent, only exigencies--such as fear of imminent destruction of evidence, hot pursuit, or immediate threats to the safety of the public or the officers--can justify a warrantless entry into an individual's home to make an arrest. Courts disapprove of police conduct that creates exigent circumstances used to justify a warrantless arrest in a suspect's home, but will often sustain such arrests when the police can demonstrate that their actions were motivated by legitimate law enforcement needs.

The special protections afforded to dwellings extend to rented premises, hotel rooms, and temporary residential arrangements, but not beyond the premises to hallways, common areas, or areas where there is no legitimate expectation of privacy. Even with an arrest warrant, police may not enter the home of a third person to arrest an individual not living there unless the police have a search warrant or a reasonable belief that the person named in the arrest warrant resides in the home and is currently inside.

Searches Incident to Valid Arrests. When conducted incident to a lawful custodial arrest, a full search of the arrestee's person for both weapons and evidence is permitted. In addition, police may search containers and other items found on the arrestee's person and any items or areas within the person's immediate control. However, the search of the arrestee's person may not be unreasonably intrusive.

When police make a valid arrest of a recent occupant of a vehicle, police may search the passenger compartment of the vehicle only (1) “when it is reasonable to believe that evidence of the offense of arrest might be found in the vehicle” or (2) “when the arrestee is unsecured and within reaching distance of the passenger compartment at the time of the search.” Authorization to search a vehicle's passenger compartment also extends to any containers found therein.

Although police must conduct searches incident to arrest reasonably promptly, substantial delay may be appropriate based on the circumstances surrounding a particular arrest. Searches incident to arrest conducted immediately before formal arrest are valid if probable cause to arrest existed prior to the search. However, if the probable cause to arrest derives from a warrantless search, then the search is not justifiable as a search incident to arrest.

In general, an arrest does not justify a search of the arrestee's entire home. In Maryland v. Buie, however, the Supreme Court held that officers may conduct a limited protective sweep of “closets and other spaces immediately adjoining the place of arrest from which an attack could be immediately launched.” This sweep may extend to a non-adjoining area only if officers have a “reasonable belief based on specific and articulable facts that the area to be swept harbors an individual posing a danger to those on the arrest scene.” The protective sweep may only entail a cursory inspection of those spaces in which a person may be found and cannot last longer than is reasonably necessary to dispel suspicion of danger.

Seizures of Items in Plain View. In certain situations, police may seize evidence that is in plain view without a warrant. First, the police must not “violate the Fourth Amendment in arriving at the place from which the evidence could be plainly viewed.” Thus, police may lawfully seize evidence in plain view when executing a search warrant or arrest warrant and when conducting a lawful warrantless search. Second, the incriminating character of the evidence seized must be immediately apparent, and police may not disturb or further investigate an item to discern its evidentiary value without probable cause. In order to establish probable cause, however, police may lawfully engage in investigatory action not considered a search under the Fourth Amendment.

Warrantless seizures of evidence based on the plain view doctrine may be valid even if the officers expected to find the seized evidence. The plain view doctrine also permits police to seize a container if its contents are in plain view and provide probable cause for a search. In Minnesota v. Dickerson, the Court expanded the plain view doctrine to include a “plain touch” corollary. Several courts have also adopted “plain smell” and “plain hearing” corollaries.

Exigent Circumstances. Government agents may conduct a warrantless search or seizure if (1) probable cause supports the search or seizure and (2) “exigent circumstances” exist. Exigent circumstances include imminent destruction of evidence, a threat to the safety of law enforcement officers or the general public, “hot pursuit” of a suspect by police, or likelihood that a suspect will flee before the officer can obtain a warrant.

Conducting a warrantless search or seizure to preserve evidence is justified if the police reasonably believe that unless they immediately conduct a warrantless search, the evidence is in imminent danger of being removed or destroyed. Because narcotics can be destroyed easily, criminal investigations involving narcotics often result in warrantless searches or seizures based on exigent circumstances. If exigent circumstances do not compel an immediate warrantless search, police may secure a residence to prevent destruction or removal of evidence before obtaining a search warrant.

If police reasonably believe that their safety or the safety of the general public is threatened, they may enter a dwelling and conduct a full warrantless search. In the course of such a search, police may inspect places where they reasonably believe inherently dangerous items are present. The police may also search a residence in which a violent crime has occurred if they reasonably believe victims or dangerous persons are present. Other dangers to the public may also constitute exigent circumstances. For example, a burning building or an imminent fire hazard may justify a warrantless entry into that building to extinguish the fire or eliminate the hazard. Officials at the scene of a fire or explosion do not need a warrant to remain in the building for a reasonable time after the fire has been extinguished to investigate the cause, or to search for victims or prevent further damage. Once the cause has been established, however, officials must secure a warrant to conduct a further search for evidence.

Warrantless searches may also be justified by the exigency of hot pursuit if the pursuing officers have probable cause to arrest the suspect. The Supreme Court has stated that “‘hot pursuit’ means some sort of a chase, but it need not be an extended hue and cry ‘in and about [the] public streets.”’ The hot pursuit justification for a search is not valid unless officers make an immediate and continuous pursuit of the suspect from the crime scene. The scope of a search justified by hot pursuit is only as broad as necessary to prevent the suspect from resisting arrest or escaping.

A warrantless entry or arrest may be justified if the police have reason to believe that a suspect will flee before they can obtain a warrant. The scope of such a search is only as broad as necessary to prevent the suspect from resisting arrest or escaping.

Beyond the specific examples of exigent circumstances listed above, courts will consider several factors in deciding whether an exigent-circumstances search or seizure was proper. First, courts may consider the gravity of the offense that prompts a search or seizure. Second, police must demonstrate that the search was conducted in a reasonable manner; the reasonableness inquiry requires a showing that a telephone warrant was unavailable or impractical for the searching officers. Third, the police may not take actions to create an exigency and subsequently use that exigency to justify a warrantless search or seizure. However, police do not generally have a duty to alleviate potential exigencies.

In determining whether exigent circumstances justify a warrantless entry, courts examine the totality of circumstances during the period immediately preceding the search.

Consent Searches. Government officials may conduct a search without a warrant or probable cause based upon an individual's consent, so long as that consent (1) was voluntary and (2) came from someone authorized to give it. Any evidence discovered during a consent search may be seized and admitted at trial. Consent may be express or implied, and, although a waiver of Fourth Amendment rights, need not be knowing and intelligent.

To determine whether consent was given voluntarily, courts examine the totality of the circumstances. Factors that weigh on the court's determination of voluntariness include: (1) the consenting individual's knowledge of the constitutional right to refuse consent; (2) the consenting individual's age, intelligence, education, and language ability; (3) the degree to which the consenting individual cooperates with the police; (4) the consenting individual's attitude about the likelihood of the discovery of contraband; and (5) the length of detention and the nature of questioning, including police threat of physical punishment or other coercive behavior. No single factor is dispositive. Moreover, the influence of drugs, intoxication, and mental agitation do not automatically render consent involuntary. Additionally, persons in lawfully detained vehicles do not have to be advised that they are free to leave before giving voluntary consent. The prosecution bears the burden of proving voluntary consent. Whether consent was voluntary is a question of fact reviewed under a “clearly erroneous” standard.

Consent is not voluntary if given only in acquiescence to a claim of lawful authority. Therefore, a search may not be justified based on consent given only after the official conducting the search asserts possession of a warrant or the possibility of obtaining a warrant if necessary. In addition, consent cannot justify a search conducted in reliance upon a warrant if a court subsequently determines that the warrant was invalid.

Consent to search is generally invalid if an illegal search or seizure occurred before the consent was given. If, however, consent to search is given under conditions sufficiently attenuated from an illegal arrest or search, evidence discovered during the subsequent search will not be suppressed.

In addition to express consent, consent may be implied by the circumstances surrounding the search, the person's prior actions or agreements, or the person's failure to object to the search.

Generally, anyone who has a reasonable expectation of privacy in the place being searched can consent to a warrantless search, and any person with common authority over, or other sufficient relationship to, the place or effects being searched can give valid consent. However, if two residents are present during the search request and one expressly denies consent, the other's consent is not valid. Courts recognize common authority to consent in each person whose mutual use of the property demonstrates “joint access or control for most purposes.” The law presumes that other users of the property assume the risk that areas under common control may be searched. The prosecution, however, bears the burden of establishing that common authority exists.

Further, a warrantless search is valid when law enforcement personnel rely on a person's “apparent authority” to consent to the search if the reliance is in good faith and is reasonable based on all facts known by police at the time of the search. Some courts have held that even if a third party is acting as an informant or other agent of the government, that person may still consent to a warrantless search if otherwise empowered to consent.

The scope of a consent search may not exceed the scope of the consent given. The scope of consent is determined by asking how a reasonable person would have understood the conversation between the officer and the suspect or third party when consent was given. Generally, the expressed object of a search defines the scope of consent, unless the suspect or third party giving consent expressly limits its scope.

Consent to search may be revoked. If a person effectively withdraws consent before the search is completed, police may not continue searching based on prior consent.

Vehicle Searches. In general, the Fourth Amendment does not require that police obtain a warrant to search an automobile when they have probable cause to believe it contains contraband or evidence of criminal activity. This exception to the warrant requirement--the “automobile exception”--stems from both the inherent mobility of vehicles and the reduced expectation of privacy that results from their pervasive regulation. Even if a vehicle's mobility is temporarily restricted or potential drivers have been secured, warrantless vehicle searches supported by probable cause are generally valid. The automobile exception has been applied to motor homes and portable campers, as well as trains, planes, and vessels.

If police have probable cause to search an entire vehicle, they may search all compartments, containers, and packages within the vehicle, including those belonging to passengers. In California v. Acevedo, the Supreme Court confronted a variant of this scenario: there, police had probable cause to believe that a particular container--a brown sack--held contraband, and they watched the defendant place the container in the trunk of his car. Although a warrant is generally required to search containers, the Court held that, when placed in a vehicle, a container may be searched on probable cause alone. In addition, the part of the vehicle in which there is probable cause to believe the container will be found may be searched, but a search of the entire vehicle is unlawful absent the existence of probable cause as to the entire vehicle.

Vehicle searches performed after exigent circumstances lapse are valid as long as the police legitimately could have searched the automobile at some point. In Chambers v. Maroney, the Supreme Court upheld the warrantless seizure and subsequent search of a car at a police station because there was probable cause at the time of the stop to justify an immediate search. Moreover, in Florida v. Meyers, the Court upheld the warrantless search of an impounded car that had already been subject to a legitimate inventory search.

An officer with probable cause to believe that a motorist has violated a traffic law may temporarily detain the motorist--regardless of the officer's motivations or suspicions --and may conduct a limited search of the motorist and vehicle for weapons upon reasonable belief that the motorist is potentially dangerous.

Legal challenges to the validity of a search under this exception are typically considered by the courts only if brought by the owner or by an operator with legitimate possession of the vehicle.

Container Searches. When police have reasonable suspicion that evidence of criminal activity is located in a movable container, they may secure the container to prevent its loss or destruction. However, a warrant is required to search the container unless an exception to the warrant requirement applies. The police may conduct a warrantless search of any container located in an automobile if probable cause exists to search the container itself or the automobile as a whole. Similarly, no warrant is necessary to search a container if its illicit contents are in plain view or may be inferred from the container's outward characteristics, if the container is an abandoned, or if the container search is simply repeated to the extent of a previously conducted private search.

Other exceptions to the warrant requirement may apply after a lawful seizure of an individual or a container. For example, following a custodial arrest, the police may search any container within the arrestee's reach. Similarly, based on reasonable suspicion, the police may detain luggage for a brief inspection, such as a canine sniff test. Finally, the police do not need a warrant to conduct an inventory search of a lawfully seized container.

Inventory Searches. After lawfully taking custody of property, police may conduct a warrantless search of that property if the owner's diminished expectation of privacy is outweighed by the government's interest in satisfying one of three purposes: (1) protecting the owner's property while it is in police custody; (2) protecting the police against claims of lost or stolen property; or (3) protecting the police from potential danger. Because the justification for the search is the production of an inventory of the container's contents, police may not conduct an inventory search in bad faith or solely for investigative purposes. Nevertheless, an inventory search may be justified by legitimate inventory purposes despite the presence of additional investigative motives.

Inventory searches are only valid if conducted according to standardized criteria and procedures. Within the framework of these criteria, however, police officers may exercise discretion to determine the appropriateness and scope of an inventory search, and they are not required to use the least intrusive means to secure property lawfully in their possession.

Courts have upheld inventory searches of vehicles lawfully in police custody, including searches of the passenger compartment, glove compartment, trunk (with some exceptions), engine compartments, and any containers in the vehicle. Police may search containers and items in the possession of lawfully detained individuals. In addition, government officials may inspect seemingly abandoned property to determine the identity of the owner, protect public safety, and inventory the property for safekeeping.

Border Searches. The Fourth Amendment does not require warrants for routine stops and searches at borders because the sovereign state and its public officials have the right to protect the United States by stopping and examining persons and property entering or leaving the country. Under the “border search” exception to the warrant requirement, routine border stops and searches of persons, luggage, personal effects, and vehicles may be conducted without probable cause or reasonable suspicion. Detention beyond a routine customs stop, however, requires at least reasonable suspicion of wrongdoing. Although the Supreme Court has not stated what distinguishes a routine from a nonroutine border search, several factors have been examined in making such a determination. Most searches of persons, luggage, personal effects, and vehicles are found to be sufficiently nonintrusive and therefore qualify as routine border searches. Circuit courts generally agree that reasonable suspicion is required to justify strip searches and X-ray examinations of persons. An even higher level of suspicion is required to justify body-cavity searches.

The border search exception also applies to searches conducted at the “functional equivalent” of a border, which is defined as the first practical detention point after a border crossing or the final port of entry. The Eleventh Circuit has established three criteria to determine whether a search occurs at the functional equivalent of a border: (1) reasonable certainty that the person or thing crossed the border; (2) reasonable certainty that there was no change in the object of the search since it crossed the border; and (3) reasonable certainty that the search was conducted as soon as practicable after the border crossing. In addition, under the “extended border search” doctrine adopted by several circuits, government officials may conduct a warrantless search beyond the border, or its functional equivalent, if the following three factors are satisfied: (1) there is “reasonable certainty” or a “high degree of probability” that a border was crossed; (2) there is “reasonable certainty” that no change in the object of the search has occurred between the time of the border crossing and the search; and (3) there is “reasonable suspicion” that criminal activity is occurring.

The border search exception allows the government to conduct warrantless searches for illegal aliens. In United States v. Martinez-Fuerte, the Supreme Court established guidelines for permanent checkpoint stops and searches and held that government officials may stop vehicles at a permanent border checkpoint for brief questioning of the driver and passengers without individualized suspicion. The vehicle and occupants may also be selectively referred to a secondary checkpoint for further questioning without individualized suspicion. Any detention or search beyond this point must be justified by consent or probable cause.

Under certain circumstances, a border search for illegal aliens may justify use of a roving border patrol. A roving border patrol may stop a vehicle in the general area of the border and question its occupants if “specific articulable facts” give rise to reasonable suspicion that the vehicle may contain illegal aliens. The officer who stops the vehicle may inquire about citizenship, immigration status, and suspicious circumstances, but any further detention or search must be based on consent or probable cause.

Searches at Sea. Coast Guard and customs officers are authorized by statute to board any vessel in U.S. territorial waters to conduct routine document and safety inspections, without a warrant or suspicion of criminal activity, if the vessel is subject to the jurisdiction or operation of U.S. law. Such document and safety inspections are limited to examining documents, visiting the vessel's public areas, examining safety equipment, and entering the hold to obtain the main beam number. Once on board a vessel, if officers develop reasonable suspicion of illegal activity, the officers can expand the search or seize the vessel. Statutes authorizing searches at sea generally do not limit how frequently an individual vessel can be searched. Warrantless document and safety inspections may be conducted even if the inspectors also suspect criminal activity.

Because there is a reasonable expectation of privacy for nonpublic areas of the vessel with limited common access, warrantless searches that extend beyond document and safety inspections require some particularized suspicion of wrongdoing. Limited searches of domestic vessels beyond document and safety inspections require reasonable suspicion of criminal activity, while full “stem-to-stern” searches require probable cause.

Customs officials are authorized to conduct document and safety inspections of foreign or domestic vessels located (1) in the United States, (2) within customs waters, (3) within a “customs-enforcement area,” or (4) in any “other authorized place.” Customs officers are not generally authorized to search vessels on the high seas. However, they are authorized to board and examine a “hovering vessel” wherever it is found, including on the high seas. Customs officers may also pursue a fleeing vessel beyond customs waters if the vessel was originally hailed within customs waters.

Because Coast Guard officers are considered customs officers, they may act pursuant to the statutory authority granted to customs officials. Unlike other customs officials, however, the Coast Guard may conduct inspections of vessels under the jurisdiction of the United States on the high seas.

Foreign vessels within U.S. territorial waters may also be boarded for document and safety inspections without reasonable suspicion of criminal activity. Coast Guard officers may board and search a foreign vessel on the high seas if they have reasonable suspicion that the vessel is subject to U.S. jurisdiction and has violated U.S. law, or if the flag state of the vessel consents. Government officials may board a “vessel without nationality” to determine its true identity. Additionally, true “vessels without nationality” may be treated as if they are U.S. vessels, and they are subject to U.S. jurisdiction and laws.

Administrative Searches. Search warrants are generally required for administrative fire, health, or safety inspections of residential or private commercial property. The probable cause requirement for administrative warrants is less stringent than that for criminal investigations because the privacy interests at stake are deemed less critical. An administrative search is valid if there is evidence of an existing violation or if the search is pursuant to a general, neutral administrative plan. A warrant is not required if there are exigent circumstances or there is valid consent to the search.

An administrative search is invalid if its sole or primary purpose is to look for evidence of criminal activity. However, a combination of administrative and investigatory purposes is acceptable, so officials may still conduct an administrative search if they have some suspicion of criminal activity. Also, if a valid administrative search discloses evidence of criminal activity, the evidence may be seized under the plain view exception to the warrant requirement.

The Supreme Court has upheld warrantless administrative searches of closely (or “pervasively”) regulated businesses. The justification for this exception to the warrant requirement is that individuals doing business in a closely regulated industry have a reduced expectation of privacy. Whether an industry is closely regulated depends on the “pervasiveness and regularity of the ... regulation” and the effect of such regulation on the privacy expectations of persons doing business in the industry. A warrantless administrative search of a closely regulated business is reasonable if: (1) there is a substantial state interest behind the regulatory scheme; (2) the search is necessary to further that scheme; and (3) the authorizing statute is an adequate substitute for the warrant requirement because it gives notice to business owners and limits the discretion of those performing the search.

Special Needs Searches. The Supreme Court has held that certain programmatic searches do not require a warrant or probable cause when they are conducted in furtherance of a government “special need” other than investigation of criminal activity. These “special needs” searches are evaluated under a two-pronged approach. First, they must further a “special need[] , beyond the normal need for law enforcement,” that would be jeopardized by a warrant or probable cause requirement. To qualify as a special need, a government interest must be a real, current, vital problem that the proposed search can effectively address. Second, if there is a special need and the individualized suspicion requirement would jeopardize that need, then courts evaluate the reasonableness of the search by balancing the nature of the intrusion on the privacy interest at stake against the government interest served by the search. Determining whether special needs searches are permissible is therefore heavily fact- and case-specific.

Special needs searches have been permitted in several distinct areas. For example, the Supreme Court has upheld programmatic suspicionless drug testing of government employees as a special needs search. The interest in public safety served by testing employees often outweighs the intrusion on employee privacy interests. However, even unintrusive drug testing is invalid if the government does not show that there is an immediate public safety concern and that the search in question effectively addresses the concern.

The Supreme Court has also upheld suspicionless drug testing of public school students as special needs searches. These searches are permissible because the warrant and probable cause requirements are impracticable in the public school context, public school students have very reduced privacy expectations, and schools' pressing need to prevent student drug use outweighs the intrusion on the students' privacy interests. Nevertheless, more intrusive searches--such as those involving a student's person or property--require particularized suspicion of wrongdoing.

Warrantless searches of the homes and property of probationers and parolees have also been permitted under the special needs exception, and these searches are upheld if reasonable. Courts determine reasonableness by balancing the state's special need to supervise parolees and probationers against the intrusion on the parolees' and probationers' privacy interests, which are greatly reduced because of their ongoing supervisory relationship with the state. The searches do not require probable cause, but they must be conducted in furtherance of the state's special need to supervise parolees and probationers and thus must be related to parole or probation conditions.

The Supreme Court has also upheld searches of the offices or persons of public employees as special needs searches. Even if a public employee has a reasonable expectation of privacy in the particular workplace area searched and the Fourth Amendment applies, probable cause is not required for workplace searches conducted either for “noninvestigatory, work-related purposes” or in the course of “investigations of work-related misconduct.” These searches are upheld if they are reasonable “under all the circumstances.” The reasonableness test consists of two inquiries: (1) whether the “action was justified at its inception,” and (2) whether the search as actually conducted was “reasonably related in scope to the circumstances which justified the interference in the first place.”

Abandoned Property. Warrants are not required for searches and seizures of abandoned property. By voluntarily abandoning property, an individual forfeits any reasonable expectation of privacy in that property, even if he or she retains an ownership interest in it.