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More Exceptions to the Warrant Requirement - Module 4 of 5

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Module 4: More Exceptions to the Warrant Requirement


In this module, we will finish our discussion on the exceptions to the warrant requirement. These exceptions include the automobile exception, exigent circumstances, inventory searches, the special needs exception, and abandoned property.

Automobile Exception

            The automobile exception to the warrant requirement arose from the 1925 Supreme Court case of Carroll v. United States.[1] In Carroll, officers pulled over the defendant’s car because they suspected the defendant of bootlegging alcohol. Although there was no visible evidence of any contraband in the car, one of the officers pounded his fist on the back of one of the car’s seats and concluded that it was harder than normal. The officer then tore open the seat cushion and discovered sixty-eight bottles of liquor. The defendant moved to suppress this evidence, arguing that this was an illegal search. The Court, however, reasoned that it was impractical for officers to get a warrant since the evidence can be destroyed or concealed before the warrant is obtained. As such, the Court held that so long as officers possessed probable cause to believe that fruits of a crime or contraband were in an automobile, officers could lawfully search it without a warrant.[2]

            In the 1970 case, Chambers v. Maroney,[3] the Court dealt with a case in which officers searched the defendant’s car after the defendant was in custody at the police station. Since the car was in police custody, there were no exigent circumstances like those in Carroll.[4] The car was in no danger of being moved, taking with it evidence. Still, the Court held that the warrantless search of the car was allowed under the automobile exception because there was probable cause to search the car.[5]

The Court in United States v. Ross,[6] extended the automobile exception to justify warrantless searches of moveable containers found in cars. The Ross Court reasoned that if probable cause justified a warrantless search of a car, then it also applied to those moveable containers that “may conceal the object of the search.”[7] The Supreme Court, however, in California v. Carney[8] clarified that the justification of these searches is still based on the exigency requirement. The Court also clarified that there is a reasonable expectation of privacy in the contents of one’s car, though that is a lower level of expectation of privacy than there is in one’s home.[9]

The reasons behind the automobile exception are important when considering whether a warrantless search is justified under the Fourth Amendment. The Court has held that the inherent mobility of a mobile home justified a warrantless search under the automobile exception even though it also functioned as the defendant’s home.[10] However, if a car is parked inside a home, such as a garage, the automobile exception does not justify police officers to enter private property without a warrant to conduct a warrantless search of the parked vehicle.[11]

Moreover, if a car is seized and held, whether due to a criminal investigation, civil forfeiture or towing from a no parking zone, the car may be searched at any time while in police custody based on the automobile exception.[12] There is no requirement that police officers conduct the search contemporaneously with the seizure of the evidence.[13] The general rule is that “if a car is readily mobile and probable cause exists to believe it contains contraband, the Fourth Amendment ... permits police to search the vehicle without more.”[14]

A car that is not “readily mobile,” though, is more analogous to a home and not subject to the automobile exception. So, if the car has no engine or is obviously not in running condition, it would not be subject to the exception. Whether a car is obviously not mobile or whether an immobile car that could be made mobile with a few quick repairs would depend on the circumstances and would be open to case-by-case analysis. For example, a car with a dead battery that could be jumped in minutes would likely be considered an automobile and subject to the exception.

Exigent Circumstances

“Exigent circumstances” is another exception to the warrant requirement of the Fourth Amendment.

Examples of exigent circumstances include when police are in “hot pursuit of a fleeing felon,” when the search is necessary to prevent “imminent destruction of evidence,” to “prevent a suspect's escape,” and to prevent or stop a risk of danger to the police or to other persons.”[15] In the case of hot pursuit, there must be probable cause to believe that the person fleeing has committed a crime. The other scenarios require probable cause to believe that the danger to people or to evidence is imminent.

When assessing the risk of danger to police or others, “the gravity of the crime and likelihood that the suspect is armed should be considered.”[16] Even if the police created the exigency, so long as they do not create the exigency by engaging in conduct that violates the Fourth Amendment, the warrantless entry into a house or another building is allowed.[17] Thus, exigent circumstances can be summed up this way:

(1) there must be circumstances which show there was a sufficient urgency in the situation,

(2) that makes it impracticable to obtain a warrant before entering the house or building, and

(3) the police possessed probable cause that the person committed a crime, there was a danger to him or others or the house or building contains evidence of a crime which would be destroyed if police had to obtain a warrant before entering.[18]

Suppose, for example, police observe a man acting in a suspicious manner. With nothing more, the officers decide to approach the man to investigate. Upon approaching the man, the man screams, “Leave me alone” and runs away. The officers pursue the man, who runs into a house. The officers run into the house after him. When they enter the house, they see tables full of money and drugs and they hear someone in the bathroom flushing something down the toilet.

In this case, a court would likely hold that there are no exigent circumstances and the officers would thus be unjustified in entering the house without a warrant. First, there is no probable cause that the man had committed a crime, as merely fleeing does justify a warrantless entry. Moreover, notwithstanding the officers’ hearing what they believe to be evidence being destroyed, since they would not know about evidence being destroyed but for wrongfully entering the house, exigent circumstances would not be justified based on evidence destruction. As such, the warrantless entry here would violate the Fourth Amendment.

If we’d change the facts a bit so that the man had committed a robbery in plain sight and was fleeing and the officers chased him into a home, on the other hand, the initial pursuit would be justified based on probable cause. As such, the entry to the home was lawful, and any contraband the police see while in the home are admissible under the “plain view” exception to the warrant requirement.

Inventory Searches

Officers do not have to get a warrant when they are performing inventory searches. In fact, officers don’t even need probable cause to conduct an inventory search. An inventory search is a search of a vehicle in police custody to properly secure its contents. The Supreme Court has held that these searches are justified on three bases: (1) the protection of property in police custody, (2) the protection of police against claims of stolen or lost property, and (3) to protect the police from any possible danger.[19]

In South Dakota v. Opperman,[20] the defendant’s car was illegally parked, so officers towed the car to the police station. At the station, the officers observed various valuables in the car and, in accordance with the police department’s policy, the officers unlocked the door and inventoried the contents of the car with the department’s standard inventory form.[21] While inventorying the contents of the car, they recovered marijuana. The defendant was subsequently arrested when he came to get his car.[22] The Court held that since the officers were following department procedure and were searching the car to secure its contents (rather than searching for evidence), this search was justified without a warrant or probable cause. So long as there is a standard police department policy that requires the inventory search and does not afford the police officers discretion, if the officers follow that procedure, the search is justified even in the absence of probable cause or a warrant.[23]

Special Needs Exception

The government may conduct warrantless searches under what has been deemed the “special needs exception.” The exception provides warrantless and even suspicionless permission to the government when special needs beyond the needs of criminal law enforcement make obtaining a warrant for each search impractical.[24] Examples of cases where the special needs exception applies include inspections for building code enforcement, border searches, airport searches, school searches, roadside checkpoints and drug testing of employees at government jobs.[25] The common theme among these exceptions is that they apply where there is a reduced expectation of privacy because of additional need for security in given places or circumstances.

When these searches are conducted without probable cause, however, they cannot be arbitrary and it should not afford limitless discretion to the government actor performing the search. There should be guidelines under which the government actor operates to ensure that the process is fair.[26] For example, a TSA officer may search a passenger’s bag if there are reasons for suspecting possible danger or contraband or even search randomly pursuant to a series of defined rules. But the TSA officer must be acting reasonably and pursuant to a defined set of rules.

In United States v. Martinez-Fuerte,[27] at issue was the constitutionality of police checkpoints at the United States-Mexico border. The Court in Martinez-Fuerte held that warrantless and suspicionless searches conducted at the border did not violate the Fourth Amendment. In making this ruling, the Court conducted a balancing test, balancing the public interest in preventing the flow of illegal drugs and undocumented immigrants from entering the United States versus the government intrusion. The Court concluded that there was an overwhelming need to prevent the flow of illegal smuggling at the United States border and this outweighed the government intrusion on the individual, which the Court concluded was minimal.[28] The decision hinged on the fact that these stops were brief, with vehicle occupants being stopped for short times to ask for documentation and a few other questions. Likewise, their abilities to seize individuals for further inquiry following the initial stop did not grant unlimited discretion to the field officers.[29] The Court ultimately held that these stops do not rise to the level of searches for Fourth Amendment purposes. As such, the need for individualized suspicion and a warrant was impracticable and would lend smugglers easier access to the United States.[30]

Years after Martinez-Fuerte was decided, the Court dealt with the constitutionality of highway sobriety checkpoints in Michigan State Police v. Sitz.[31] In Sitz, the Court used the reasonableness-balancing test employed in Martinez-Fuerte and subsequent cases to uphold these checkpoints. In Sitz, the Court conceded that stops of motorists for sobriety checkpoints were seizures. However, the Court balanced the “slight” intrusion on motorists who were being stopped against the great public interest in curbing the deleterious effects of drunk driving.[32] The Court concluded that these stops, which were not open to unlimited police discretion, were justified even absent a warrant or probable cause.

Sitz can be distinguished from the Court’s holding in City of Indianapolis v. Edmond that was decided ten years later.[33] In Edmond, the police set up various “drug interdiction checkpoints” where every car would be stopped, the drivers would be observed for signs of impairment, the officers would look at the interior contents of the cars and drug-sniffing dogs would be walked around the cars to detect the presence of illegal narcotics. For officers to conduct further inquiries at these checkpoints following those initial steps, individualized suspicion based on articulable facts was required.[34] The Edmond Court declined to extend the special needs doctrine to these cases and held that these searches and seizures violated the Fourth Amendment since their “primary purpose was to detect evidence of ordinary criminal wrongdoing.”[35]

From the backdrop of these cases, the following three-pronged rule can be established for special needs searches which justify warrantless searches:

(1) There must exist some special need beyond the needs of law enforcement;

(2) the searches must be based on individualized suspicion or be based on a neutral plan that removes arbitrary discretion from the searching parties; and

(3) the benefits to the government and society must outweigh the privacy interests of the individuals.[36]

Abandoned Property

Katz v. United States established that for an unlawful search or seizure to occur, there must be an infringement of a place or area in which a person has a reasonable expectation of privacy. The abandoned property doctrine focuses on the reasonable expectation of privacy test in its analysis. Generally, if a person abandons property, she has no reasonable expectation of privacy in that property. Thus, police can search or seize that property without probable cause, any suspicion or warrant. Property is abandoned when there was an “intentional relinquishment of [the privacy] expectation with regard to the property in question.”[37] For example, in California v. Greenwood,[38] the Court held that officers could conduct a warrantless search through a person’s trash left on the curb for garbage pickup, since there was no reasonable expectation of privacy in the garbage. Relinquishing the property could reasonably allow the conclusion that anyone, including the police, can seize and search the abandoned property.[39]

In our last module, we will discuss the Fourth Amendment, its application and role in modern society, and its role in the ever-evolving and continued advances of technology in the lives of individuals.


[1] Caroll v. United States, 267 U.S. 132 (1925).

[2] Id. at 154-56.

[4] Id. at 51-52.

[5] Id. at 52.

[7] Id. at 825.

[9] Id. at 390-91.

[10] Id. at 392-94.

[11] Collins v. Virginia, No. 16-1027, 584 U.S. __ at *7 (2018)

[13] Id.

[14] Maryland v. Dyson, 527 US 465, 467 (1999) (quoting from Pennsylvania v. Labron, 518 U. S. 938, 940 (1996)) (internal quotation marks omitted).

[15] Minnesota v. Olson, 495 U.S. 91, 100 (1990) (internal citations and quotation marks omitted).

[16] See id.

[18] Robert M. Bloom & Mark S. Brodin, Examples & Explanations: Criminal Procedure: The Constitution and the Police § 6.2 (5th ed. 2006).

[20] Id.

[21] Id. at 365-66.

[22] Id. at 366.

[23] Id. at 383.

[25] See Mickey Shmitt, “The Special Needs Doctrine and Reduced Expectations of Privacy Under the Fourth Amendment,” Fed. Lawyer (July 2016), 42, 43; see also Antoine McNamara, “The ‘Special Needs’ of Prison, Probation, and Parole,” 82 N.Y.U. L. Rev. 209, 213 (2007).

[27] United States v. Martinez-Fuerte, 428 U.S. 543 (1976).

[28] Id. at 557.

[29] Id. at 559.

[30] Id. at 556-64.

[32] Id. at 450-52.

[34] Id. at 35.

[35] Id. at 37-40.

[36] McNamara, supra note 26, at 213.

[39] See id. at 39-41.