2.3: Chapter 4 - What Is a Search?- More Specifics

The Fourth Amendment protects the people’s “persons, houses, papers, and effects.” While this language is quite broad, it does not include everything someone might possess or wish to protect from intrusion. For example, if one owns agricultural land far from any “house,” that land is not a person, a house, a paper, or an effect. Police searches of such land, therefore, are not “searches” regulated by the Fourth Amendment. In the next two cases, the Court attempts to define the barrier separating the “curtilage” (an area near a house that is treated as a “house” for Fourth Amendment purposes) from the “open fields” (which enjoy no Fourth Amendment protection).

Supreme Court of the United States

Ray Oliver v. United States

Decided April 17, 1984 – 466 U.S. 170

Justice POWELL delivered the opinion of the Court.

The “open fields” doctrine, first enunciated by this Court in Hester v. United States, 265 U.S. 57 (1924), permits police officers to enter and search a field without a warrant. We granted certiorari to clarify confusion that has arisen as to the continued vitality of the doctrine.

I

Acting on reports that marihuana was being raised on the farm of petitioner Oliver, two narcotics agents of the Kentucky State Police went to the farm to investigate. Arriving at the farm, they drove past petitioner’s house to a locked gate with a “No Trespassing” sign. A footpath led around one side of the gate. The agents walked around the gate and along the road for several hundred yards, passing a barn and a parked camper. At that point, someone standing in front of the camper shouted: “No hunting is allowed, come back up here.” The officers shouted back that they were Kentucky State Police officers, but found no one when they returned to the camper. The officers resumed their investigation of the farm and found a field of marihuana over a mile from petitioner’s home.

Petitioner was arrested and indicted for “manufactur[ing]” a “controlled substance.” After a pretrial hearing, the District Court suppressed evidence of the discovery of the marihuana field. Applying Katz v. United States, the court found that petitioner had a reasonable expectation that the field would remain private because petitioner “had done all that could be expected of him to assert his privacy in the area of farm that was searched.” He had posted “No Trespassing” signs at regular intervals and had locked the gate at the entrance to the center of the farm. Further, the court noted that the field itself is highly secluded: it is bounded on all sides by woods, fences, and embankments and cannot be seen from any point of public access. The court concluded that this was not an “open” field that invited casual intrusion.

The Court of Appeals for the Sixth Circuit, sitting en banc, reversed the District Court. The court concluded that Katz, upon which the District Court relied, had not impaired the vitality of the open fields doctrine of Hester. Rather, the open fields doctrine was entirely compatible with Katz’ emphasis on privacy. The court reasoned that the “human relations that create the need for privacy do not ordinarily take place” in open fields, and that the property owner’s common-law right to exclude trespassers is insufficiently linked to privacy to warrant the Fourth Amendment’s protection. We granted certiorari.

II

The rule announced in Hester v. United States was founded upon the explicit language of the Fourth Amendment. That Amendment indicates with some precision the places and things encompassed by its protections. As Justice Holmes explained for the Court in his characteristically laconic style: “[T]he special protection accorded by the Fourth Amendment to the people in their ‘persons, houses, papers, and effects,’ is not extended to the open fields. The distinction between the latter and the house is as old as the common law.”

Nor are the open fields “effects” within the meaning of the Fourth Amendment. In this respect, it is suggestive that James Madison’s proposed draft of what became the Fourth Amendment preserves “[t]he rights of the people to be secured in their persons, their houses, their papers, and their other property, from all unreasonable searches and seizures….” Although Congress’ revisions of Madison’s proposal broadened the scope of the Amendment in some respects, the term “effects” is less inclusive than “property” and cannot be said to encompass open fields. We conclude, as did the Court in deciding Hester v. United States, that the government’s intrusion upon the open fields is not one of those “unreasonable searches” proscribed by the text of the Fourth Amendment.

III

This interpretation of the Fourth Amendment’s language is consistent with the understanding of the right to privacy expressed in our Fourth Amendment jurisprudence. Since Katz v. United States, the touchstone of [Fourth] Amendment analysis has been the question whether a person has a “constitutionally protected reasonable expectation of privacy.” The Amendment does not protect the merely subjective expectation of privacy, but only those “expectation[s] that society is prepared to recognize as ‘reasonable.’”

A

No single factor determines whether an individual legitimately may claim under the Fourth Amendment that a place should be free of government intrusion not authorized by warrant. In assessing the degree to which a search infringes upon individual privacy, the Court has given weight to such factors as the intention of the Framers of the Fourth Amendment, the uses to which the individual has put a location, and our societal understanding that certain areas deserve the most scrupulous protection from government invasion. These factors are equally relevant to determining whether the government’s intrusion upon open fields without a warrant or probable cause violates reasonable expectations of privacy and is therefore a search proscribed by the Amendment.

In this light, the rule of Hester v. United States that we reaffirm today may be understood as providing that an individual may not legitimately demand privacy for activities conducted out of doors in fields, except in the area immediately surrounding the home. This rule is true to the conception of the right to privacy embodied in the Fourth Amendment. The Amendment reflects the recognition of the Framers that certain enclaves should be free from arbitrary government interference. For example, the Court since the enactment of the Fourth Amendment has stressed “the overriding respect for the sanctity of the home that has been embedded in our traditions since the origins of the Republic.”

In contrast, open fields do not provide the setting for those intimate activities that the Amendment is intended to shelter from government interference or surveillance. There is no societal interest in protecting the privacy of those activities, such as the cultivation of crops, that occur in open fields. Moreover, as a practical matter these lands usually are accessible to the public and the police in ways that a home, an office, or commercial structure would not be. It is not generally true that fences or “No Trespassing” signs effectively bar the public from viewing open fields in rural areas. [P]etitioner Oliver concede[s] that the public and police lawfully may survey lands from the air. For these reasons, the asserted expectation of privacy in open fields is not an expectation that “society recognizes as reasonable.”

The historical underpinnings of the open fields doctrine also demonstrate that the doctrine is consistent with respect for “reasonable expectations of privacy.” As Justice Holmes observed in Hester, the common law distinguished “open fields” from the “curtilage,” the land immediately surrounding and associated with the home. The distinction implies that only the curtilage, not the neighboring open fields, warrants the Fourth Amendment protections that attach to the home. Thus, courts have extended Fourth Amendment protection to the curtilage; and they have defined the curtilage, as did the common law, by reference to the factors that determine whether an individual reasonably may expect that an area immediately adjacent to the home will remain private. Conversely, the common law implies, as we reaffirm today, that no expectation of privacy legitimately attaches to open fields.

We conclude, from the text of the Fourth Amendment and from the historical and contemporary understanding of its purposes, that an individual has no legitimate expectation that open fields will remain free from warrantless intrusion by government officers.

B

Nor would a case-by-case approach provide a workable accommodation between the needs of law enforcement and the interests protected by the Fourth Amendment. Under this approach, police officers would have to guess before every search whether landowners had erected fences sufficiently high, posted a sufficient number of warning signs, or located contraband in an area sufficiently secluded to establish a right of privacy. The lawfulness of a search would turn on “‘[a] highly sophisticated set of rules, qualified by all sorts of ifs, ands, and buts and requiring the drawing of subtle nuances and hairline distinctions ….’” This Court repeatedly has acknowledged the difficulties created for courts, police, and citizens by an ad hoc, case-by-case definition of Fourth Amendment standards to be applied in differing factual circumstances.

IV

Nor is the government’s intrusion upon an open field a “search” in the constitutional sense because that intrusion is a trespass at common law. The existence of a property right is but one element in determining whether expectations of privacy are legitimate. “‘The premise that property interests control the right of the Government to search and seize has been discredited.’” “[E]ven a property interest in premises may not be sufficient to establish a legitimate expectation of privacy with respect to particular items located on the premises or activity conducted thereon.”

The common law may guide consideration of what areas are protected by the Fourth Amendment by defining areas whose invasion by others is wrongful. The law of trespass, however, forbids intrusions upon land that the Fourth Amendment would not proscribe. For trespass law extends to instances where the exercise of the right to exclude vindicates no legitimate privacy interest. Thus, in the case of open fields, the general rights of property protected by the common law of trespass have little or no relevance to the applicability of the Fourth Amendment.

V

We conclude that the open fields doctrine, as enunciated in Hester, is consistent with the plain language of the Fourth Amendment and its historical purposes. Moreover, Justice Holmes’ interpretation of the Amendment in Hester accords with the “reasonable expectation of privacy” analysis developed in subsequent decisions of this Court. We therefore affirm Oliver v. United States.

Justice MARSHALL, with whom Justice BRENNAN and Justice STEVENS join, dissenting.

[P]olice officers, ignoring clearly visible “No Trespassing” signs, entered upon private land in search of evidence of a crime. At a spot that could not be seen from any vantage point accessible to the public, the police discovered contraband, which was subsequently used to incriminate the owner of the land. [P]olice [did not] have a warrant authorizing their activities.

The Court holds that police conduct of this sort does not constitute an “unreasonable search” within the meaning of the Fourth Amendment. The Court reaches that startling conclusion by two independent analytical routes. First, the Court argues that, because the Fourth Amendment by its terms renders people secure in their “persons, houses, papers, and effects,” it is inapplicable to trespasses upon land not lying within the curtilage of a dwelling. Second, the Court contends that “an individual may not legitimately demand privacy for activities conducted out of doors in fields, except in the area immediately surrounding the home.” Because I cannot agree with either of these propositions, I dissent.

I

The first ground on which the Court rests its decision is that the Fourth Amendment “indicates with some precision the places and things encompassed by its protections,” and that real property is not included in the list of protected spaces and possessions. This line of argument has several flaws. Most obviously, it is inconsistent with the results of many of our previous decisions, none of which the Court purports to overrule. For example, neither a public telephone booth nor a conversation conducted therein can fairly be described as a person, house, paper, or effect; yet we have held that the Fourth Amendment forbids the police without a warrant to eavesdrop on such a conversation. Nor can it plausibly be argued that an office or commercial establishment is covered by the plain language of the Amendment; yet we have held that such premises are entitled to constitutional protection if they are marked in a fashion that alerts the public to the fact that they are private.

Indeed, the Court’s reading of the plain language of the Fourth Amendment is incapable of explaining even its own holding in this case. The Court rules that the curtilage, a zone of real property surrounding a dwelling, is entitled to constitutional protection. We are not told, however, whether the curtilage is a “house” or an “effect”—or why, if the curtilage can be incorporated into the list of things and spaces shielded by the Amendment, a field cannot.

II

The second ground for the Court’s decision is its contention that any interest a landowner might have in the privacy of his woods and fields is not one that “society is prepared to recognize as ‘reasonable.’” The mode of analysis that underlies this assertion is certainly more consistent with our prior decisions than that discussed above. But the Court’s conclusion cannot withstand scrutiny.

A

We have frequently acknowledged that privacy interests are not coterminous with property rights. However, because “property rights reflect society’s explicit recognition of a person’s authority to act as he wishes in certain areas, [they] should be considered in determining whether an individual’s expectations of privacy are reasonable.” Indeed, the Court has suggested that, insofar as “[o]ne of the main rights attaching to property is the right to exclude others, … one who owns or lawfully possesses or controls property will in all likelihood have a legitimate expectation of privacy by virtue of this right to exclude.”

It is undisputed that Oliver owned the land into which the police intruded. That fact alone provides considerable support for their assertion of legitimate privacy interests in their woods and fields. But even more telling is the nature of the sanctions that Oliver could invoke, under local law, for violation of their property rights. In Kentucky, a knowing entry upon fenced or otherwise enclosed land, or upon unenclosed land conspicuously posted with signs excluding the public, constitutes criminal trespass. Thus, positive law not only recognizes the legitimacy of Oliver’s insistence that strangers keep off [his] land, but subjects those who refuse to respect [his] wishes to the most severe of penalties—criminal liability. Under these circumstances, it is hard to credit the Court’s assertion that Oliver’s expectations of privacy were not of a sort that society is prepared to recognize as reasonable.

* * *

In United States v. Dunn, decided three years after Oliver v. United States, the Court applied the principles set forth in Oliver to new facts.

Supreme Court of the United States

United States v. Ronald Dunn

Decided March 3, 1987 – 480 U.S. 294

Justice WHITE delivered the opinion of the Court.

We granted the Government’s petition for certiorari to decide whether the area near a barn, located approximately 50 yards from a fence surrounding a ranch house, is, for Fourth Amendment purposes, within the curtilage of the house. The Court of Appeals for the Fifth Circuit held that the barn lay within the house’s curtilage, and that the District Court should have suppressed certain evidence obtained as a result of law enforcement officials’ intrusion onto the area immediately surrounding the barn. We conclude that the barn and the area around it lay outside the curtilage of the house, and accordingly reverse the judgment of the Court of Appeals.

I

Respondent Ronald Dale Dunn and a codefendant, Robert Lyle Carpenter, were convicted by a jury of conspiring to manufacture phenylacetone and amphetamine, and to possess amphetamine with intent to distribute. Respondent was also convicted of manufacturing these two controlled substances and possessing amphetamine with intent to distribute. The events giving rise to respondent’s apprehension and conviction began in 1980 when agents from the Drug Enforcement Administration (DEA) discovered that Carpenter had purchased large quantities of chemicals and equipment used in the manufacture of amphetamine and phenylacetone. DEA agents obtained warrants from a Texas state judge authorizing installation of miniature electronic transmitter tracking devices, or “beepers,” in an electric hot plate stirrer, a drum of acetic anhydride, and a container holding phenylacetic acid, a precursor to phenylacetone. All of these items had been ordered by Carpenter. On September 3, 1980, Carpenter took possession of the electric hot plate stirrer, but the agents lost the signal from the “beeper” a few days later. The agents were able to track the “beeper” in the container of chemicals, however, from October 27, 1980, until November 5, 1980, on which date Carpenter’s pickup truck, which was carrying the container, arrived at respondent’s ranch. Aerial photographs of the ranch property showed Carpenter’s truck backed up to a barn behind the ranch house. The agents also began receiving transmission signals from the “beeper” in the hot plate stirrer that they had lost in early September and determined that the stirrer was on respondent’s ranch property.

Respondent’s ranch comprised approximately 198 acres and was completely encircled by a perimeter fence. The property also contained several interior fences, constructed mainly of posts and multiple strands of barbed wire. The ranch residence was situated ½ mile from a public road. A fence encircled the residence and a nearby small greenhouse. Two barns were located approximately 50 yards from this fence. The front of the larger of the two barns was enclosed by a wooden fence and had an open overhang. Locked, waist-high gates barred entry into the barn proper, and netting material stretched from the ceiling to the top of the wooden gates.

On the evening of November 5, 1980, law enforcement officials made a warrantless entry onto respondent’s ranch property. A DEA agent accompanied by an officer from the Houston Police Department crossed over the perimeter fence and one interior fence. Standing approximately midway between the residence and the barns, the DEA agent smelled what he believed to be phenylacetic acid, the odor coming from the direction of the barns. The officers approached the smaller of the barns—crossing over a barbed wire fence—and, looking into the barn, observed only empty boxes. The officers then proceeded to the larger barn, crossing another barbed wire fence as well as a wooden fence that enclosed the front portion of the barn. The officers walked under the barn’s overhang to the locked wooden gates and, shining a flashlight through the netting on top of the gates, peered into the barn. They observed what the DEA agent thought to be a phenylacetone laboratory. The officers did not enter the barn. At this point the officers departed from respondent’s property, but entered it twice more on November 6 to confirm the presence of the phenylacetone laboratory.

On November 6, 1980, at 8:30 p.m., a Federal Magistrate issued a warrant authorizing a search of respondent’s ranch. DEA agents and state law enforcement officials executed the warrant on November 8, 1980. The officers arrested respondent and seized chemicals and equipment, as well as bags of amphetamines they discovered in a closet in the ranch house.

The District Court denied respondent’s motion to suppress all evidence seized pursuant to the warrant and respondent [was] convicted. [T]he Court of Appeals reversed respondent’s conviction. The court concluded that the search warrant had been issued based on information obtained during the officers’ unlawful warrantless entry onto respondent’s ranch property and, therefore, all evidence seized pursuant to the warrant should have been suppressed. Underpinning this conclusion was the court’s reasoning that “the barn in question was within the curtilage of the residence and was within the protective ambit of the fourth amendment.” The Government thereupon submitted a petition for certiorari [questioning] whether the barn lay within the curtilage of the house. We granted the petition and now reverse.

II

The curtilage concept originated at common law to extend to the area immediately surrounding a dwelling house the same protection under the law of burglary as was afforded the house itself. The concept plays a part, however, in interpreting the reach of the Fourth Amendment.

Drawing upon the Court’s own cases and the cumulative experience of the lower courts that have grappled with the task of defining the extent of a home’s curtilage, we believe that curtilage questions should be resolved with particular reference to four factors: the proximity of the area claimed to be curtilage to the home, whether the area is included within an enclosure surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to protect the area from observation by people passing by. We do not suggest that combining these factors produces a finely tuned formula that, when mechanically applied, yields a “correct” answer to all extent-of-curtilage questions. Rather, these factors are useful analytical tools only to the degree that, in any given case, they bear upon the centrally relevant consideration—whether the area in question is so intimately tied to the home itself that it should be placed under the home’s “umbrella” of Fourth Amendment protection. Applying these factors to respondent’s barn and to the area immediately surrounding it, we have little difficulty in concluding that this area lay outside the curtilage of the ranch house.

First. The record discloses that the barn was located 50 yards from the fence surrounding the house and 60 yards from the house itself. Standing in isolation, this substantial distance supports no inference that the barn should be treated as an adjunct of the house.

Second. It is also significant that respondent’s barn did not lie within the area surrounding the house that was enclosed by a fence. Viewing the physical layout of respondent’s ranch in its entirety, it is plain that the fence surrounding the residence serves to demark a specific area of land immediately adjacent to the house that is readily identifiable as part and parcel of the house. Conversely, the barn—the front portion itself enclosed by a fence—and the area immediately surrounding it, stands out as a distinct portion of respondent’s ranch, quite separate from the residence.

Third. It is especially significant that the law enforcement officials possessed objective data indicating that the barn was not being used for intimate activities of the home. The aerial photographs showed that the truck Carpenter had been driving that contained the container of phenylacetic acid was backed up to the barn, “apparently,” in the words of the Court of Appeals, “for the unloading of its contents.” When on respondent’s property, the officers’ suspicion was further directed toward the barn because of “a very strong odor” of phenylacetic acid. As the DEA agent approached the barn, he “could hear a motor running, like a pump motor of some sort ….” Furthermore, the officers detected an “extremely strong” odor of phenylacetic acid coming from a small crack in the wall of the barn. Finally, as the officers were standing in front of the barn, immediately prior to looking into its interior through the netting material, “the smell was very, very strong … [and the officers] could hear the motor running very loudly.” When considered together, the above facts indicated to the officers that the use to which the barn was being put could not fairly be characterized as so associated with the activities and privacies of domestic life that the officers should have deemed the barn as part of respondent’s home.

Fourth. Respondent did little to protect the barn area from observation by those standing in the open fields. Nothing in the record suggests that the various interior fences on respondent’s property had any function other than that of the typical ranch fence; the fences were designed and constructed to corral livestock, not to prevent persons from observing what lay inside the enclosed areas.

III

Respondent submits an alternative basis for affirming the judgment below, one that was presented to but ultimately not relied upon by the Court of Appeals. Respondent asserts that he possessed an expectation of privacy, independent from his home’s curtilage, in the barn and its contents, because the barn is an essential part of his business.

We may accept, for the sake of argument, respondent’s submission that his barn enjoyed Fourth Amendment protection and could not be entered and its contents seized without a warrant. But it does not follow on the record before us that the officers’ conduct and the ensuing search and seizure violated the Constitution. It follows that no constitutional violation occurred here when the officers crossed over respondent’s ranch-style perimeter fence, and over several similarly constructed interior fences, prior to stopping at the locked front gate of the barn. As previously mentioned, the officers never entered the barn, nor did they enter any other structure on respondent’s premises. Once at their vantage point, they merely stood, outside the curtilage of the house and in the open fields upon which the barn was constructed, and peered into the barn’s open front. And, standing as they were in the open fields, the Constitution did not forbid them to observe the phenylacetone laboratory located in respondent’s barn.

Under Oliver and Hester, there is no constitutional difference between police observations conducted while in a public place and while standing in the open fields. Similarly, the fact that the objects observed by the officers lay within an area that we have assumed, but not decided, was protected by the Fourth Amendment does not affect our conclusion. The Fourth Amendment “has never been extended to require law enforcement officers to shield their eyes when passing by a home on public thoroughfares.” Here, the officers’ use of the beam of a flashlight, directed through the essentially open front of respondent’s barn, did not transform their observations into an unreasonable search within the meaning of the Fourth Amendment.

The officers lawfully viewed the interior of respondent’s barn, and their observations were properly considered by the Magistrate in issuing a search warrant for respondent’s premises. Accordingly, the judgment of the Court of Appeals is reversed.

Justice BRENNAN, with whom Justice MARSHALL joins, dissenting.

The Government agents’ intrusions upon Ronald Dunn’s privacy and property violated the Fourth Amendment for two reasons. First, the barnyard invaded by the agents lay within the protected curtilage of Dunn’s farmhouse. Second, the agents infringed upon Dunn’s reasonable expectation of privacy in the barn and its contents. Our society is not so exclusively urban that it is unable to perceive or unwilling to preserve the expectation of farmers and ranchers that barns and their contents are protected from (literally) unwarranted government intrusion.

The Court states that curtilage questions are often resolved through evaluation of four factors. The Court applies this test and concludes that Dunn’s barn and barnyard were not within the curtilage of his dwelling. This conclusion overlooks the role a barn plays in rural life and ignores extensive authority holding that a barn, when clustered with other outbuildings near the residence, is part of the curtilage.

State and federal courts have long recognized that a barn, like many other outbuildings, is “a domestic building constituting an integral part of that group of structures making up the farm home.” Consequently, the general rule is that the “[c]urtilage includes all outbuildings used in connection with a residence, such as garages, sheds, [and] barns … connected with and in close vicinity of the residence.”

The overwhelming majority of state courts have consistently held that barns are included within the curtilage of a farmhouse. Federal courts, too, have held that barns, like other rural outbuildings, lie within the curtilage of the farmhouse. Thus, case law demonstrates that a barn is an integral part of a farm home and therefore lies within the curtilage. The Court’s opinion provides no justification for its indifference to the weight of state and federal precedent.

The Fourth Amendment prohibits police activity which, if left unrestricted, would jeopardize individuals’ sense of security or would too heavily burden those who wished to guard their privacy. In this case, in order to look inside respondent’s barn, the DEA agents traveled a one-half mile off a public road over respondent’s fenced-in property, crossed over three additional wooden and barbed wire fences, stepped under the eaves of the barn, and then used a flashlight to peer through otherwise opaque fishnetting. For the police habitually to engage in such surveillance—without a warrant—is constitutionally intolerable. Because I believe that farmers’ and ranchers’ expectations of privacy in their barns and other outbuildings are expectations society would regard as reasonable, and because I believe that sanctioning the police behavior at issue here does violence to the purpose and promise of the Fourth Amendment, I dissent.

Notes, Comments, and Questions

In both Oliver and Dunn, police walked onto someone’s land without permission. In describing the “open fields doctrine,” the Oliver Court stated: “The “open fields” doctrine, first enunciated by this Court in Hester v. United States, 265 U.S. 57 (1924), permits police officers to enter and search a field without a warrant.”

Consider whether that statement is truly accurate. Is it truly lawful for police to wander uninvited on the open fields of suspects? Perhaps it would be more accurate to state: “Police should not do this, but if they do, the Fourth Amendment has nothing to say about it.” The Hester case cited by the Court in Oliver may provide a clue. In the syllabus, the Court describes police witnesses who “held no warrant and were trespassers on the land.” By definition, trespassers are violating the law. We do not call it a “trespass” when someone walks on the property of another to visit as an invited guest, or to knock on the door and leave literature about religion or politics, or to execute a valid search warrant.

If officers who find useful (and admissible) evidence while trespassing in the open fields of suspects are breaking the law, should they be punished? Is it plausible to believe that they will be? If, as seems more likely, police departments would laud such behavior rather than condemning it, does that raise questions about the sensibility of the open fields doctrine?

At common law, the crimes of arson and burglary (which are both crimes against the dwelling), defined “house” as both a dwelling house and buildings located within the curtilage. Fourth Amendment law essentially imports this principle.

So what is curtilage? Curtilage is: “The land or yard adjoining a house, usually within an enclosure. Under the Fourth Amendment, the curtilage is an area usually protected from warrantless searches.” Black’s Law Dictionary (11th ed. 2019).

Some students may wonder if United States v. Jones, 565 U.S. 400 (2012), which was decided well after Dunn and Oliver, invalidates the open fields doctrine. The answer is no. Yes, Jones does reiterate the importance of trespass to Fourth Amendment law. And yes, officers who wander uninvited on the “open fields” of suspects likely commit trespass as defined by state law. Nonetheless, according to cases like Dunn and Oliver, the open fields are not among the “persons, houses, papers, and effects” protected by the Fourth Amendment. While Jones affects how courts will decide whether police have acted improperly with respect to someone’s “house,” the case does not affect how “house” is defined. The “open fields” remain excluded from Fourth Amendment protection.

Because the Court treats the curtilage surrounding a home as part of a “house” for Fourth Amendment purposes, police officers normally cannot walk on to curtilage and look around with neither permission nor a warrant. In response to this restriction, police have flown over houses and curtilage, using their eyes and cameras to gain information relevant to criminal investigations.

The next two cases consider whether the Fourth Amendment applies when police observe the curtilage from the air.

Supreme Court of the United States

California v. Ciraolo

Decided May 19, 1986 – 476 U.S. 207

Chief Justice BURGER delivered the opinion of the Court.

We granted certiorari to determine whether the Fourth Amendment is violated by aerial observation without a warrant from an altitude of 1,000 feet of a fenced-in backyard within the curtilage of a home.

I

On September 2, 1982, Santa Clara Police received an anonymous telephone tip that marijuana was growing in respondent’s backyard. Police were unable to observe the contents of respondent’s yard from ground level because of a 6-foot outer fence and a 10-foot inner fence completely enclosing the yard. Later that day, Officer Shutz, who was assigned to investigate, secured a private plane and flew over respondent’s house at an altitude of 1,000 feet, within navigable airspace; he was accompanied by Officer Rodriguez. Both officers were trained in marijuana identification. From the overflight, the officers readily identified marijuana plants 8 feet to 10 feet in height growing in a 15- by 25-foot plot in respondent’s yard; they photographed the area with a standard 35mm camera.

On September 8, 1982, Officer Shutz obtained a search warrant on the basis of an affidavit describing the anonymous tip and their observations; a photograph depicting respondent’s house, the backyard, and neighboring homes was attached to the affidavit as an exhibit. The warrant was executed the next day and 73 plants were seized; it is not disputed that these were marijuana.

After the trial court denied respondent’s motion to suppress the evidence of the search, respondent pleaded guilty to a charge of cultivation of marijuana. The California Court of Appeal reversed, however, on the ground that the warrantless aerial observation of respondent’s yard which led to the issuance of the warrant violated the Fourth Amendment. That court held first that respondent’s backyard marijuana garden was within the “curtilage” of his home, under Oliver v. United States. The court emphasized that the height and existence of the two fences constituted “objective criteria from which we may conclude he manifested a reasonable expectation of privacy by any standard.”

Examining the particular method of surveillance undertaken, the court then found it “significant” that the flyover “was not the result of a routine patrol conducted for any other legitimate law enforcement or public safety objective, but was undertaken for the specific purpose of observing this particular enclosure within [respondent’s] curtilage.” It held this focused observation was “a direct and unauthorized intrusion into the sanctity of the home” which violated respondent’s reasonable expectation of privacy. The California Supreme Court denied the State’s petition for review.

We granted the State’s petition for certiorari. We reverse.

The State argues that respondent has “knowingly exposed” his backyard to aerial observation, because all that was seen was visible to the naked eye from any aircraft flying overhead. The State analogizes its mode of observation to a knothole or opening in a fence: if there is an opening, the police may look.

The California Court of Appeal accepted the analysis that unlike the casual observation of a private person flying overhead, this flight was focused specifically on a small suburban yard, and was not the result of any routine patrol overflight. Respondent contends he has done all that can reasonably be expected to tell the world he wishes to maintain the privacy of his garden within the curtilage without covering his yard. Such covering, he argues, would defeat its purpose as an outside living area; he asserts he has not “knowingly” exposed himself to aerial views.

II

The touchstone of Fourth Amendment analysis is whether a person has a “constitutionally protected reasonable expectation of privacy.” Katz posits a two-part inquiry: first, has the individual manifested a subjective expectation of privacy in the object of the challenged search? Second, is society willing to recognize that expectation as reasonable?

Clearly—and understandably—respondent has met the test of manifesting his own subjective intent and desire to maintain privacy as to his unlawful agricultural pursuits. It can reasonably be assumed that the 10-foot fence was placed to conceal the marijuana crop from at least street-level views. So far as the normal sidewalk traffic was concerned, this fence served that purpose, because respondent “took normal precautions to maintain his privacy.”

Yet a 10-foot fence might not shield these plants from the eyes of a citizen or a policeman perched on the top of a truck or a two-level bus. Whether respondent therefore manifested a subjective expectation of privacy from all observations of his backyard, or whether instead he manifested merely a hope that no one would observe his unlawful gardening pursuits, is not entirely clear in these circumstances. Respondent appears to challenge the authority of government to observe his activity from any vantage point or place if the viewing is motivated by a law enforcement purpose, and not the result of a casual, accidental observation.

We turn, therefore, to the second inquiry under Katz, i.e., whether that expectation is reasonable. In pursuing this inquiry, we must keep in mind that “[t]he test of legitimacy is not whether the individual chooses to conceal assertedly ‘private’ activity,” but instead “whether the government’s intrusion infringes upon the personal and societal values protected by the Fourth Amendment.”

Respondent argues that because his yard was in the curtilage of his home, no governmental aerial observation is permissible under the Fourth Amendment without a warrant. At common law, the curtilage is the area to which extends the intimate activity associated with the ‘sanctity of a man’s home and the privacies of life.’” The protection afforded the curtilage is essentially a protection of families and personal privacy in an area intimately linked to the home, both physically and psychologically, where privacy expectations are most heightened. The claimed area here was immediately adjacent to a suburban home, surrounded by high double fences. This close nexus to the home would appear to encompass this small area within the curtilage. Accepting, as the State does, that this yard and its crop fall within the curtilage, the question remains whether naked-eye observation of the curtilage by police from an aircraft lawfully operating at an altitude of 1,000 feet violates an expectation of privacy that is reasonable.

That the area is within the curtilage does not itself bar all police observation. The Fourth Amendment protection of the home has never been extended to require law enforcement officers to shield their eyes when passing by a home on public thoroughfares. Nor does the mere fact that an individual has taken measures to restrict some views of his activities preclude an officer’s observations from a public vantage point where he has a right to be and which renders the activities clearly visible.

The observations by Officers Shutz and Rodriguez in this case took place within public navigable airspace in a physically nonintrusive manner; from this point they were able to observe plants readily discernible to the naked eye as marijuana. That the observation from aircraft was directed at identifying the plants and the officers were trained to recognize marijuana is irrelevant. Such observation is precisely what a judicial officer needs to provide a basis for a warrant. Any member of the public flying in this airspace who glanced down could have seen everything that these officers observed. On this record, we readily conclude that respondent’s expectation that his garden was protected from such observation is unreasonable and is not an expectation that society is prepared to honor.

Reversed.

Justice POWELL, with whom Justice BRENNAN, Justice MARSHALL, and Justice BLACKMUN join, dissenting.

Concurring in Katz v. United States, Justice Harlan warned that any decision to construe the Fourth Amendment as proscribing only physical intrusions by police onto private property “is, in the present day, bad physics as well as bad law, for reasonable expectations of privacy may be defeated by electronic as well as physical invasion.” Because the Court today ignores that warning in an opinion that departs significantly from the standard developed in Katz for deciding when a Fourth Amendment violation has occurred, I dissent.

The Court [holds] that respondent’s expectation of privacy in the curtilage of his home, although reasonable as to intrusions on the ground, was unreasonable as to surveillance from the navigable airspace. In my view, the Court’s holding rests on only one obvious fact, namely, that the airspace generally is open to all persons for travel in airplanes. The Court does not explain why this single fact deprives citizens of their privacy interest in outdoor activities in an enclosed curtilage.

The Court’s holding must rest solely on the fact that members of the public fly in planes and may look down at homes as they fly over them. The Court does not explain why it finds this fact to be significant. One may assume that the Court believes that citizens bear the risk that air travelers will observe activities occurring within backyards that are open to the sun and air. This risk, the Court appears to hold, nullifies expectations of privacy in those yards even as to purposeful police surveillance from the air.

This line of reasoning is flawed. First, the actual risk to privacy from commercial or pleasure aircraft is virtually nonexistent. Travelers on commercial flights, as well as private planes used for business or personal reasons, normally obtain at most a fleeting, anonymous, and nondiscriminating glimpse of the landscape and buildings over which they pass. The risk that a passenger on such a plane might observe private activities, and might connect those activities with particular people, is simply too trivial to protect against. It is no accident that, as a matter of common experience, many people build fences around their residential areas, but few build roofs over their backyards. Therefore, contrary to the Court’s suggestion, people do not “‘knowingly expos[e]’” their residential yards “‘to the public’” merely by failing to build barriers that prevent aerial surveillance.

Since respondent had a reasonable expectation of privacy in his yard, aerial surveillance undertaken by the police for the purpose of discovering evidence of crime constituted a “search” within the meaning of the Fourth Amendment. The indiscriminate nature of aerial surveillance, illustrated by Officer Shutz’ photograph of respondent’s home and enclosed yard as well as those of his neighbors, poses “far too serious a threat to privacy interests in the home to escape entirely some sort of Fourth Amendment oversight.” Therefore, I would affirm the judgment of the California Court of Appeal ordering suppression of the marijuana plants. I dissent.

* * *

In the next case, the Court applies the rule set forth in Ciraolo, which concerned fixed-wing aircraft, to police use of helicopters.

Supreme Court of the United States

Florida v. Michael Riley

Decided Jan. 23, 1989 – 488 U.S. 445

Justice WHITE announced the judgment of the Court and delivered an opinion, in which THE CHIEF JUSTICE, Justice SCALIA, and Justice KENNEDY join.

On certification to it by a lower state court, the Florida Supreme Court addressed the following question: “Whether surveillance of the interior of a partially covered greenhouse in a residential backyard from the vantage point of a helicopter located 400 feet above the greenhouse constitutes a ‘search’ for which a warrant is required under the Fourth Amendment.” The court answered the question in the affirmative, and we granted the State’s petition for certiorari challenging that conclusion.

Respondent Riley lived in a mobile home located on five acres of rural property. A greenhouse was located 10 to 20 feet behind the mobile home. Two sides of the greenhouse were enclosed. The other two sides were not enclosed but the contents of the greenhouse were obscured from view from surrounding property by trees, shrubs, and the mobile home. The greenhouse was covered by corrugated roofing panels, some translucent and some opaque. At the time relevant to this case, two of the panels, amounting to approximately 10% of the roof area, were missing. A wire fence surrounded the mobile home and the greenhouse, and the property was posted with a “DO NOT ENTER” sign.

This case originated with an anonymous tip to the Pasco County Sheriff’s office that marijuana was being grown on respondent’s property. When an investigating officer discovered that he could not see the contents of the greenhouse from the road, he circled twice over respondent’s property in a helicopter at the height of 400 feet. With his naked eye, he was able to see through the openings in the roof and one or more of the open sides of the greenhouse and to identify what he thought was marijuana growing in the structure. A warrant was obtained based on these observations, and the ensuing search revealed marijuana growing in the greenhouse. Respondent was charged with possession of marijuana under Florida law. The trial court granted his motion to suppress; the Florida Court of Appeals reversed but certified the case to the Florida Supreme Court, which quashed the decision of the Court of Appeals and reinstated the trial court’s suppression order.

We agree with the State’s submission that our decision in California v. Ciraolo controls this case.

In this case, as in Ciraolo, the property surveyed was within the curtilage of respondent’s home. Riley no doubt intended and expected that his greenhouse would not be open to public inspection, and the precautions he took protected against ground-level observation. Because the sides and roof of his greenhouse were left partially open, however, what was growing in the greenhouse was subject to viewing from the air. Under the holding in Ciraolo, Riley could not reasonably have expected the contents of his greenhouse to be immune from examination by an officer seated in a fixed-wing aircraft flying in navigable airspace at an altitude of 1,000 feet or, as the Florida Supreme Court seemed to recognize, at an altitude of 500 feet, the lower limit of the navigable airspace for such an aircraft. Here, the inspection was made from a helicopter, but as is the case with fixed-wing planes, “private and commercial flight [by helicopter] in the public airways is routine” in this country, and there is no indication that such flights are unheard of in Pasco County, Florida. Riley could not reasonably have expected that his greenhouse was protected from public or official observation from a helicopter had it been flying within the navigable airspace for fixed-wing aircraft.

Nor on the facts before us, does it make a difference for Fourth Amendment purposes that the helicopter was flying at 400 feet when the officer saw what was growing in the greenhouse through the partially open roof and sides of the structure. We would have a different case if flying at that altitude had been contrary to law or regulation. But helicopters are not bound by the lower limits of the navigable airspace allowed to other aircraft. Any member of the public could legally have been flying over Riley’s property in a helicopter at the altitude of 400 feet and could have observed Riley’s greenhouse. The police officer did no more. This is not to say that an inspection of the curtilage of a house from an aircraft will always pass muster under the Fourth Amendment simply because the plane is within the navigable airspace specified by law. But it is of obvious importance that the helicopter in this case was not violating the law, and there is nothing in the record or before us to suggest that helicopters flying at 400 feet are sufficiently rare in this country to lend substance to respondent’s claim that he reasonably anticipated that his greenhouse would not be subject to observation from that altitude. Neither is there any intimation here that the helicopter interfered with respondent’s normal use of the greenhouse or of other parts of the curtilage. As far as this record reveals, no intimate details connected with the use of the home or curtilage were observed, and there was no undue noise, and no wind, dust, or threat of injury. In these circumstances, there was no violation of the Fourth Amendment.

Justice O’CONNOR, concurring in the judgment.

I concur in the judgment reversing the Supreme Court of Florida because I agree that police observation of the greenhouse in Riley’s curtilage from a helicopter passing at an altitude of 400 feet did not violate an expectation of privacy “that society is prepared to recognize as ‘reasonable.’” I write separately, however, to clarify the standard I believe follows from California v. Ciraolo. In my view, the plurality’s approach rests the scope of Fourth Amendment protection too heavily on compliance with FAA regulations whose purpose is to promote air safety, not to protect “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.”

Ciraolo’s expectation of privacy was unreasonable not because the airplane was operating where it had a “right to be,” but because public air travel at 1,000 feet is a sufficiently routine part of modern life that it is unreasonable for persons on the ground to expect that their curtilage will not be observed from the air at that altitude. Although “helicopters are not bound by the lower limits of the navigable airspace allowed to other aircraft,” there is no reason to assume that compliance with FAA regulations alone determines “‘whether the government’s intrusion infringes upon the personal and societal values protected by the Fourth Amendment.’” Because the FAA has decided that helicopters can lawfully operate at virtually any altitude so long as they pose no safety hazard, it does not follow that the expectations of privacy “society is prepared to recognize as ‘reasonable’” simply mirror the FAA’s safety concerns.

In determining whether Riley had a reasonable expectation of privacy from aerial observation, the relevant inquiry after Ciraolo is not whether the helicopter was where it had a right to be under FAA regulations. Rather, consistent with Katz, we must ask whether the helicopter was in the public airways at an altitude at which members of the public travel with sufficient regularity that Riley’s expectation of privacy from aerial observation was not “one that society is prepared to recognize as ‘reasonable.’” Thus, in determining “‘whether the government’s intrusion infringes upon the personal and societal values protected by the Fourth Amendment,’” it is not conclusive to observe, as the plurality does, that “[a]ny member of the public could legally have been flying over Riley’s property in a helicopter at the altitude of 400 feet and could have observed Riley’s greenhouse.” Nor is it conclusive that police helicopters may often fly at 400 feet. If the public rarely, if ever, travels overhead at such altitudes, the observation cannot be said to be from a vantage point generally used by the public and Riley cannot be said to have “knowingly expose[d]” his greenhouse to public view. However, if the public can generally be expected to travel over residential backyards at an altitude of 400 feet, Riley cannot reasonably expect his curtilage to be free from such aerial observation.

Because there is reason to believe that there is considerable public use of airspace at altitudes of 400 feet and above, and because Riley introduced no evidence to the contrary before the Florida courts, I conclude that Riley’s expectation that his curtilage was protected from naked-eye aerial observation from that altitude was not a reasonable one. However, public use of altitudes lower than that—particularly public observations from helicopters circling over the curtilage of a home—may be sufficiently rare that police surveillance from such altitudes would violate reasonable expectations of privacy, despite compliance with FAA air safety regulations.

Justice BRENNAN, with whom Justice MARSHALL and Justice STEVENS, join, dissenting.

The Court holds today that police officers need not obtain a warrant based on probable cause before circling in a helicopter 400 feet above a home in order to investigate what is taking place behind the walls of the curtilage. I cannot agree that the Fourth Amendment to the Constitution tolerates such an intrusion on privacy and personal security.

The opinion for a plurality of the Court reads almost as if Katz v. United States had never been decided. Notwithstanding the disclaimers of its final paragraph, the opinion relies almost exclusively on the fact that the police officer conducted his surveillance from a vantage point where, under applicable Federal Aviation Administration regulations, he had a legal right to be.

The plurality undertakes no inquiry into whether low-level helicopter surveillance by the police of activities in an enclosed backyard is consistent with the “aims of a free and open society.” Instead, it summarily concludes that Riley’s expectation of privacy was unreasonable because “[a]ny member of the public could legally have been flying over Riley’s property in a helicopter at the altitude of 400 feet and could have observed Riley’s greenhouse.” This observation is, in turn, based solely on the fact that the police helicopter was within the airspace within which such craft are allowed by federal safety regulations to fly. It is a curious notion that the reach of the Fourth Amendment can be so largely defined by administrative regulations issued for purposes of flight safety.¹

The question before us must be not whether the police were where they had a right to be, but whether public observation of Riley’s curtilage was so commonplace that Riley’s expectation of privacy in his backyard could not be considered reasonable. To say that an invasion of Riley’s privacy from the skies was not impossible is most emphatically not the same as saying that his expectation of privacy within his enclosed curtilage was not “one that society is prepared to recognize as ‘reasonable.’”

Perhaps the most remarkable passage in the plurality opinion is its suggestion that the case might be a different one had any “intimate details connected with the use of the home or curtilage [been] observed.” What, one wonders, is meant by “intimate details”? If the police had observed Riley embracing his wife in the backyard greenhouse, would we then say that his reasonable expectation of privacy had been infringed? Where in the Fourth Amendment or in our cases is there any warrant for imposing a requirement that the activity observed must be “intimate” in order to be protected by the Constitution?

It is difficult to avoid the conclusion that the plurality has allowed its analysis of Riley’s expectation of privacy to be colored by its distaste for the activity in which he was engaged. It is indeed easy to forget, especially in view of current concern over drug trafficking, that the scope of the Fourth Amendment’s protection does not turn on whether the activity disclosed by a search is illegal or innocuous. But we dismiss this as a “drug case” only at the peril of our own liberties. Justice Frankfurter once noted that “[i]t is a fair summary of history to say that the safeguards of liberty have frequently been forged in controversies involving not very nice people,” United States v. Rabinowitz, 339 U.S. 56 (1950) (dissenting opinion), and nowhere is this observation more apt than in the area of the Fourth Amendment, whose words have necessarily been given meaning largely through decisions suppressing evidence of criminal activity. The principle enunciated in this case determines what limits the Fourth Amendment imposes on aerial surveillance of any person, for any reason. If the Constitution does not protect Riley’s marijuana garden against such surveillance, it is hard to see how it will prohibit the government from aerial spying on the activities of a law-abiding citizen on her fully enclosed outdoor patio. As Professor Amsterdam has eloquently written: “The question is not whether you or I must draw the blinds before we commit a crime. It is whether you and I must discipline ourselves to draw the blinds every time we enter a room, under pain of surveillance if we do not.” 58 Minn. L. Rev. 349, 403.

The issue in this case is, ultimately, “how tightly the Fourth Amendment permits people to be driven back into the recesses of their lives by the risk of surveillance.” The Court today approves warrantless helicopter surveillance from an altitude of 400 feet. The Fourth Amendment demands that we temper our efforts to apprehend criminals with a concern for the impact on our fundamental liberties of the methods we use. I hope it will be a matter of concern to my colleagues that the police surveillance methods they would sanction were among those described 40 years ago in George Orwell’s dread vision of life in the 1980’s:

“The black-mustachio’d face gazed down from every commanding corner. There was one on the house front immediately opposite. BIG BROTHER IS WATCHING YOU, the caption said. … In the far distance a helicopter skimmed down between the roofs, hovered for an instant like a bluebottle, and darted away again with a curving flight. It was the Police Patrol, snooping into people’s windows.” Nineteen Eighty-Four (1949).

Who can read this passage without a shudder, and without the instinctive reaction that it depicts life in some country other than ours? I respectfully dissent.

Notes, Comments, and Questions

Supreme Court precedent strongly suggests that as long as police pilots obey the law (such as FAA regulations on minimum altitudes), the “reasonable expectation of privacy test” will not prevent police from flying over a home. Justice O’Connor’s concurrence argues that legality is not everything, and her vote was necessary to assemble a majority of votes to affirm the conviction in Riley. Nonetheless, it is difficult to see how a lower court could hold that flights similar to those in Ciraolo and Riley—which the Supreme Court deemed not to be “searches”—have somehow violated the Fourth Amendment, at least under Katz. (Because Ciraolo and Riley were decided before the Court reinvigorated trespass-based Fourth Amendment analysis in Jones, new arguments may be available under that case’s reasoning.)

Diligent defense counsel may wish to examine whether state or local laws restrict overflights more strictly than FAA regulations. Especially as remote-controlled helicopters (a.k.a. “drones”) become widely available at low prices, police can easily fly camera-toting aircraft over the homes of suspects. If a municipality prohibits such conduct by the general public, then perhaps police who violate local ordinances will also violate reasonable expectations of privacy.

What are the limits for observations from the air? Consider an officer who uses a drone equipped with a video camera to monitor a suspect through his bedroom window. There is nothing to suggest that drones flying in neighborhoods are sufficiently rare; a drone with streaming video can be purchased for about $60 at Target. Search or no search? Why or why not? Does the outcome change if there is a local ordinance limiting the public’s use of drones to public spaces?

Students interested in the law regulating drones (also known as “unmanned aircraft”) can find information on the website of Jonathan Rupprecht, a Florida lawyer specializing in drones. He has collected various sources of drone law, including federal statutes, federal regulations (issued by several agencies, not solely by the Federal Aviation Administration), and state laws. As Rupprecht observes, it remains undecided how much of state drone law will be preempted by federal law.

Additionally, students can look at CALI’s lesson Drones: Unmanned Aircraft Systems, to learn more about the legal aspects of drones in both military and civilian settings.