STATE OF FLORIDA, PETITIONER V. FRANK J. BRADY, ET AL. No. 81-1636 In the Supreme Court of the United States October Term, 1982 On Writ of Certiorari to the Supreme Court of Florida Brief for the United States as Amicus Curiae in Support of Petitioner TABLE OF CONTENTS Interest of the United States Statement Summary of argument Argument: I. In the absence of substantial measures to exclude the public, there is no reasonable expectation of privacy in a field that invokes the protection of the Fourth Amendment A. The open fields doctrine retains its vitality today B. The open fields doctrine is not restricted to fields that are unfenced and unposted C. Even when a landowner takes substantial measures to exclude persons from a field, that field may reasonably be searched without a warrant or probable cause II. The entry onto respondent Brady's field did not violate the Fourth Amendment Conclusion QUESTION PRESENTED Whether the warrantless entry by police onto a fenced and posted 1800 acre field violated the Fourth Amendment. INTEREST OF THE UNITED STATES This case presents an important question under the Fourth Amendment concerning the scope of the "open fields" doctrine first enunciated in Hester v. United States, 265 U.S. 57 (1924). Although this is a state prosecution, the circumstances under which police may enter onto a field without a search warrant is a question that arises frequently in federal cases. Accordingly, the United States has a direct and significant interest in the standard applicable to such cases. STATEMENT 1. On April 21, 1978, Florida law enforcement agents received information that an aircraft loaded with illegal drugs would be landing on an airstrip located on a cattle ranch belonging to respondent Frank Brady (Pet. App. A2; J.A. 37-38, 53-54). The airstrip was in the middle of the property, an 1800 acre field fenced with barbed wire and posted with no trespassing and no hunting signs. The only structures on the Brady property were a house trailer and some type of barn. The trailer was located approximately two thousand feet away from the end of the airstrip (J.A. 28-33). Police surveillance was set up just outside the property that night, but no planes were observed landing (Pet. App. A2-A3; J.A. 39-40, 54-55). On April 22, the police received a more specific tip indicating that a plane would land on the Brady ranch at about dusk that evening, using a particular radio frequency to trigger the runway lights (Pet. App. A3; J.A. 40). Three surveillance teams stationed themselves on or around the Brady property. In order to position themselves near the airstrip, one team of officers entered the field by cutting a chain lock on one of the gates and another team climbed over the barbed wire fence (Pet. App. A3; J.A. 41-42, 48-50, 55). After the plane landed, the officers ascertained that bales of marijuana apparently were being unloaded (J.A. 43-44, 50-53, 56). They then converged on the plane and arrested the respondents. /1/ 2. Respondents Brady, Eckard, and Elliot were charged with delivery and possession of marijuana in excess of 100 pounds, conspiracy to possess marijuana in excess of 100 pounds, and importation of marijuana. Respondents List and Manuel were charged with attempted possession of marijuana in excess of 100 pounds (Pet. App. A2). Prior to trail, the trial judge granted a motion to suppress the seized evidence because no search warrant had been obtained (J.A. 58-61). The Florida District Court of Appeal, Fourth District, affirmed (Pet. App. A29-A45). The Florida Supreme Court also affirmed the suppression order (Pet. App. A1-A27). The court rejected the State's argument that, under the "open fields" doctrine of Hester v. United States, 265 U.S. 57 (1924), the warrantless entry onto Brady's land did not violate the Fourth Amendment. The court recognized that Hester has not been overruled, but it held that under the analysis of Katz v. United States, 389 U.S. 347 (1967), "if the owner or occupier of a field seeks to keep it private and demonstrates an actual intention to do so, and his expectation is one that society is willing to recognize as reasonable, then Fourth Amendment protections extend to activities in that field" (Pet. App. A9; emphasis in original). Because the property was fenced and posted, the court first concluded that respondent Brady had manifested an expectation of privacy in his field (id. at A13). Second, while acknowledging that activity conducted in an open field does not ordinarily warrant a significant expectation of privacy, the court held that under the facts of this case and "in light of the size of the property and the precautions taken by respondent (Brady)," an expectation of privacy was reasonable (id. at A17). See also id. at A22-A23. Justice McDonald dissented (id. at A25-A27), finding that the Brady "property, although fenced, is essentially an open field" (id. at A26) and hence that, under the Katz analysis, respondents could have no reasonable expectation of privacy there. /2/ SUMMARY OF ARGUMENT I. A. In Hester v. United States, 265 U.S. 57, 59 (1924), this Court held that "the special protection accorded by the Fourth Amendment to the people in their 'persons, houses, papers, and effects,' is not extended to the open fields." This rule was not undermined by this Court's decision in Katz v. United States, 389 U.S. 347 (1967), which held that warrantless wiretapping of a public telephone violated an individual's legitimate expectation of privacy. To the contrary, this Court cited Hester with approval in Katz itself and has done so in subsequent decisions. This is because the property interest that a landowner has in his field is not equivalent to a privacy interest that gives rise to Fourth Amendment protection. Apart from the curtilage surrounding a residence, an individual does not have an expectation of privacy that society is prepared to recognize as "reasonable" in an open field. B. Posting and fencing an open field does not necessarily alter its character so as to create a protected Fourth Amendment privacy interest in the field. While posting a field puts an outsider on notice that he is about to commit a trespass, the facts of Hester make clear that the "open fields" doctrine is based on the lack of privacy expectation in the field and does not depend on whether or not the police officer is aware that he is trespassing. The posting of "No Trespass" signs, as a practical matter, gives a landowner little assurance that outsiders will not enter his property; indeed, state statutes typically give law enforcement officials, such as game wardens, specific authority to enter private posted lands to monitor compliance with state wildlife laws. See, e.g., Fla. Stat. Ann. Section 372.07(1) and (2)(a) (West 1974). Nor does the existence of a fence surrounding an open field necessarily increase the expectation of privacy in that field. Fences around large areas of rural property are usually designed to mark a boundary or to keep animals in rather than to keep people out, and they pose little impediment to entry by a person. Like posting, the existence of such a fence does not give a landowner a reasonable assurance that outsiders will not enter onto his land. Accordingly, the courts generally have held that there is no protected Fourth Amendment privacy interest in a field that is surrounded by a nonexclusionary fence. C. A landowner may, however, take substantial measures to exclude outsiders from his field, such as erecting a barrier designed to prevent entry by other persons. Arguably, such action would give him a reasonable expectation of some degree of privacy in the field. Even so, that expectation of privacy is a limited one that does not approach the privacy interest that an individual has in his home or office. Even a field surrounded by an exclusionary fence is subject to observation from the air and thus cannot be regarded as wholly private. More important, if the police are mistaken in their suspicion of criminal activity, their unjustified entry into the field is only a minimal disruption of an individual's privacy; the officers will observe only what is ordinarily found in a field, such as cornstalks and cows. On the other hand, when police enter a home, they intrude into the area that people reserve for their most personal and private matters. Because of the magnitude of the privacy invasion involved in a search of a home, this Court has concluded that the Fourth Amendment establishes two prerequisites to sustain the reasonableness of such a search: (1) the substantive standard for balancing societal law enforcement interests against individual privacy interests is probable cause; (2) as a procedural protection to minimize the risk of a mistake, probable cause is to be determined by a neutral and detached magistrate. In the case of an entry onto a field, where the privacy intrusion is so much smaller, it is reasonable that the prerequisites to such an entry be more relaxed, as the Court has recognized in other contexts where there is a substantially reduced privacy intrusion. For example, the warrant requirement does not apply to a search of an automobile, which is an area of reduced privacy expectation. See United States v. Chadwick, 433 U.S. 1, 12 (1977). And police may effect brief investigatory detentions on suspicion that does not amount to probable cause. See, e.g., Terry v. Ohio, 392 U.S. 1 (1968). In a situation where police have reason to suspect that evidence of criminal activity will be found in a field -- even one surrounded by an exclusionary fence arguably justifying recognition of some degree of privacy interest -- it is "reasonable" within the meaning of the Fourth Amendment to enter the field on the basis of a reasonable suspicion of criminal activity, given the comparatively minor privacy intrusion entailed in the entry. II. Applying the foregoing analysis, the record indicates that the entry onto respondent Brady's field did not violate the Fourth Amendment. While the field was fenced, outsiders continually trespassed on the ranch and the police officers here climbed over the fence without apparent difficulty. Thus, the fence appears not to have been an exclusionary one, but rather an ordinary livestock fence, which the courts generally have recognized as not creating a legitimate expectation of privacy in a field. But even apart from this, the information received by the officers gave them reasonable suspicion that criminal activity was afoot on the Brady ranch, and it was therefore "reasonable" under the Fourth Amendment for them to enter to investigate their suspicion and to thwart serious criminal activity. ARGUMENT I. IN THE ABSENCE OF SUBSTANTIAL MEASURES TO EXCLUDE THE PUBLIC, THERE IS NO REASONABLE EXPECTATION OF PRIVACY IN A FIELD THAT INVOKES THE PROTECTION OF THE FOURTH AMENDMENT A. The Open Fields Doctrine Retains Its Vitality Today The "open fields" doctrine was first enunciated by this Court in Hester v. United States, 265 U.S. 57 (1924). In Hester, two revenue officers entered onto the defendant's property and, from a distance of 50-100 yards from his house, saw the defendant hand another person what appeared to be a gallon jug of illicitly distilled whiskey. The Court held, in a unanimous decision authored by Justice Holmes, that the fact that the officers had trespassed on the defendant's property was not a reason for suppressing the observations made by the officers. The Court explained (265 U.S. at 59): "(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." While the Court's opinion in Hester is conclusory, it has become the source of a well-entrenched rule of law, viz., that the open areas beyond the house and its "curtilage" are not within those areas protected by the Fourth Amendment. /3/ This rule is soundly based in the specific language of the Fourth Amendment and its limited proscription of only those searches and seizures that are "unreasonable." The Florida Supreme Court held that this Court's decision in Katz v. United States, 389 U.S. 347 (1967), undermined the continuing viability of Hester. See Pet. App. A6-A7. But there is nothing in Katz to suggest repudiation of the open fields doctrine. In Katz, the Court held that the Fourth Amendment protected against warrantless wiretapping private conversations conducted in a public telephone booth. To be sure, Katz recognizes that the Fourth Amendment may extent to an area that is not within the curtilage of a privately-owned building, but it does so in the specific context of electronic surveillance of a phone booth; it certainly does not suggest extension of Fourth Amendment protection to an area like a field, even if an individual may prefer that his activity there remain private. /4/ Indeed, both the majority opinion in Katz and Justice Harlan's oft-cited concurring opinion, each of which was relied upon by the Florida Supreme Court (Pet. App. A7-A9), discuss Hester approvingly. Citing Hester, the Court noted in Katz that "(i)t appears to be common ground * * * that an open field is not (an area protected by the Fourth Amendment)." 389 U.S. at 351 n.8. Justice Harlan stated that a "telephone booth is an area where, like a home, * * * and unlike a field (citing Hester), a person has a constitutionally protected reasonable expectation of privacy." Id. at 360. See also id. at 361. Moreover, since Katz this Court has relied on Hester and consistently cited it approvingly in other decisions. See Air Pollution Variance Board v. Western Alfalfa Corp., 416 U.S. 861, 865-866 (1974); see also Rakas v. Illinois, 439 U.S. 128, 144 n.12 (1978); G.M. Leasing Corp. v. United States, 429 U.S. 338, 352 (1977); United States v. Santana, 427 U.S. 38, 42 (1976); Cady v. Dombrowski, 413 U.S. 433, 450 (1973); Bivens v. Six Unknown Named Agents of Federal Bureau of Narcotics, 403 U.S. 388, 393 n.6 (1971). An examination of the reasoning of Katz also makes clear that it casts no doubt on the continuing vitality of Hester. Katz holds that the Fourth Amendment protects areas where an individual has a "justifiabl(e)" expectation of privacy. 389 U.S. at 353. As the Florida court noted (Pet. App. A8-A9), Justice Harlan's concurring opinion suggests a two-part inquiry to determine whether an area is protected by the Fourth Amendment (389 U.S. at 361): whether the individual, by his conduct, has exhibited a subjective expectation of privacy and whether that expectation is "one that society is prepared to recognize as 'reasonable.' " See generally Smith v. Maryland, 442 U.S. 735, 740 (1979); Rakas v. Illinois, supra, 439 U.S. at 143-144 n.12. The Court's holding in Hester, in terms of the Katz analysis, is simply that society does not recognize as reasonable an expectation of privacy in open fields, and nothing in Katz suggests that a different rule should apply. See, e.g., United States v. Oliver, No. 80-5437 (6th Cir. May 5, 1982) (en banc), petition for cert. pending, No. 82-15 (filed July 2, 1982); United States v. Freie, 545 F.2d 1217, 1223 (9th Cir. 1976), cert. denied, 430 U.S. 966 (1977); Patler v. Slayton, 503 F.2d 472, 478 (4th Cir. 1974); see also S. Rep. No. 1097, 90th Cong., 2d Sess. 90 (1968), quoted in United States v. Paul, 614 F.2d 115, 119 (6th Cir.) (Phillips, J., concurring), cert. denied, 446 U.S. 941 (1980) (discussion of federal wiretapping statute noting that expectation of privacy "clearly unjustified" in an open field). It is true, of course, that entry onto open fields violates the landowner's property rights in most instances. But Hester stands for the proposition that a legal property interest is not necessarily equivalent to an interest protected by the Fourth Amendment, and the Court has consistently adhered to this view. See generally Rakas v. Illinois, supra, 439 U.S. at 143-144 n.12. This principle was not challenged in Katz; on the contrary, it is Katz that emphasizes that the focus of the Fourth Amendment is on legitimate privacy interests. See 389 U.S. at 351-353. It is also undoubtedly true that an individual may have a strong subjective expectation of privacy in activity he carries on in an open field, depending on the distance of the field from areas frequented by the public. The probability that another person will observe his activity "in the middle of nowhere" is small. But an individual has an analogous expectation of privacy in activities undertaken late at night in an apparently deserted alley or forest; obviously, however, he can have no constitutional objection if a policeman stumbles upon him when he is engaged in criminal activity. Clearly, an expectation of privacy entitled to Fourth Amendment protection cannot be grounded merely on the improbability of being observed. In sum, both before and after Katz, there is no basis for recognizing a legitimate expectation of privacy in an open field. /5/ B. The Open Fields Doctrine Is Not Restricted To Fields That Are Unfenced And Unposted The Florida Supreme Court conceded (Pet. App. A23) that "(a) ctivities carried on in a truly open field, or in any area which one knowingly exposes to the public, are not subject to Fourth Amendment protections." The court, however, apparently held that an expectation of privacy protected by the Fourth Amendment necessarily attaches to any field that has been fenced or posted with "No Trespassing" signs. But, as numerous other courts have held, these common features of farmland or ranches do not transform a field into an area protected by the Fourth Amendment. The effect of posting a field is to put an individual on notice that he is about to trespass onto private property, and a fence generally has the same effect. Clearly, a police officer who enters onto fenced and posted property has not simply committed an unintentional trespass. But it is evident from Hester itself that the open fields doctrine does not apply only to unintentional trespasses. While the opinion in Hester does not specify whether the property was fenced or posted, one of the revenue officers himself testified that he supposed the officers were trespassing on Hester's property. 265 U.S. at 58. Thus, the Court found no Fourth Amendment violation in Hester even though the officers were aware that they were trespassing. Hester holds that a knowing trespass onto an open field, although perhaps violative of state law, does not violate the Fourth Amendment because such a field is not an area in which there is a legitimate expectation of privacy; the posting of "No Trespassing" signs does not alter that conclusion. Moreover, state statutes typically permit access by law enforcement officers to private property under circumstances in which access to enclosed structures would not be allowed. For example, Florida law permits game and fish commission officials and wildlife officers to "enter upon any land or waters of the state for performance of their lawful duties * * * and such entry shall not constitute a trespass" and to "(g)o upon all premises, posted or otherwise" in order to determine whether the state game and wildlife laws are being violated, so long as they do not enter any buildings. Fla. Stat. Ann. Section 372.07(1) and (2)(a) (West 1974). This specific authorization is illustrative of a more general recognition that in many situations a law enforcement officer is empowered to enter upon private property in the performance of his duties where an entry by a private party would constitute a trespass. See, e.g., United States v. Knight, 451 F.2d 275, 278 (5th Cir. 1971), cert. denied, 405 U.S. 965 (1972); United States v. Capps, 435 F.2d 637, 640 & n.4 (9th Cir. 1970). Thus, a landowner who posts his field can have no reasonable expectation of complete privacy from law enforcement officers. By the same token, the existence of a fence around rural property does not necessarily give rise to a greater expectation of privacy in a field. Ordinarily, the purpose of such a fence is to mark a boundary or to keep farm animals within the property. As one court has noted, such rural fences "are designed more to keep livestock under control than to keep people out." State v. Stanton, 490 P.2d 1274, 1279 (Or. Ct. App. 1971). See also United States v. Williams, 581 F.2d 451, 454 (5th Cir. 1978), cert. denied, 440 U.S. 972 (1979); Giddens v. State, 156 Ga. App. 258, 259, 274 S.E. 2d 595, 597 (1980), cert. denied, 450 U.S. 1026 (1981). Rural landowners recognize that hunters and other members of the public frequently enter private fields (see State v. Cemper, 209 Neb. 376, 307 N.W.2d 820, 823 (1981); State v. Stanton, supra, 490 P.2d at 1279), and that an ordinary livestock fence does not present much of an obstacle to entry by a person (see Giddens v. State, supra, 156 Ga. App. at 259, 274 S.E. 2d at 597). /6/ Accordingly, while he may hope that persons will be discouraged from trespassing or inadvertently wandering onto his property, a landowner has little expectation that persons with a strong desire to enter his field will be deterred by posting the field or by the presence of a livestock fence surrounding the entire property. /7/ Recognizing the inevitable limitations on the degree of privacy that reasonably can be expected in an open field, the courts of appeals, both before and after Katz, generally have declined to suppress evidence seized in an open field, even where the property is fenced and posted. For example, in United States ex rel. Saiken v. Bensinger, 546 F.2d 1292 (7th Cir. 1976), cert. denied, 431 U.S. 930 (1977), the court held that a fenced goosehouse came within the ambit of the open fields doctrine because the goosehouse was beyond the curtilage and the fence was for the purpose of containing the geese. Significantly, the court dismissed out of hand the relevance of a perimeter fence, finding that most of the 20-acre farm "was clearly open fields" even though the entire farm was surrounded by a fence. Id. at 1297. In United States v. Oliver, supra, slip op. 7, the court explained that "(t)he legal principles that protect privacy * * * do not protect * * * the open field -- even one the owner has posted with a 'no trespass' sign." See also United States v. Williams, supra; McDowell v. United States, 383 F.2d 599 (8th Cir. 1967); Care v. United States, 231 F.2d 22 (10th Cir.), cert. denied, 351 U.S. 932 (1956); Janney v. United States, 206 F.2d 601 (4th Cir. 1953); Stark v. United States, 44 F.2d 946 (8th Cir. 1930); but see United States v. Dunn, 674 F.2d 1093, 1100 (5th Cir. 1982) (fenced-in barn held within curtilage). /8/ By the same token, several state court decisions have recognized the applicability of the open fields doctrine despite posting or the existence of a fence. See Luman v. State, 629 P.2d 1275 (Okla. 1981) (barbed wire fence); State v. Cemper, supra (entry though open gate in barbed wire fence); Giddens v. State, supra (barbed wire fence); People v. Lashmett, 71 Ill. App. 3d 429, 389 N.E. 2d 888 (1979), cert. denied, 444 U.S. 1081 (1980) (officers climbed over two fences); Ford v. State, 264 Ark. 141, 142, 569 S.W.2d 105, 106 (1978), cert. denied, 441 U.S. 947 (1979) (posted and fenced field with locked gate); State v. Wren, 115 Ariz, 257, 564 P.2d 946 (Ct. App. 1977) (barbed wire fence); Commonwealth v. Janek, 242 Pa. Super. Ct. 340, 363 A.2d 1299 (1976) (field posted and surrounded by embankments and barbed wire fences); State v. Stanton, supra ("a couple" of livestock fences); Casey v. State, 87 Nev. 413, 488 P.2d 546 (1971) (fenced ranch); contra, State v. Byers, 359 So.2d 84 (La. 1978) (marijuana field held not "open" because posted and road chained). These decisions rest simply on the notion that posting a field or the existence of a nonexclusionary perimeter fence does not sufficiently change the nature of a person's expectation of privacy in an open field that it is reasonable to attach a constitutionally protected privacy right to items present or activities carried on in that field. /9/ C. Even When A Landowner Takes Substantial Measures To Exclude Persons From A Field, That Field May Reasonably Be Searched Without A Warrant Or Probable Cause The foregoing discussion is not meant to suggest that there are no circumstances in which an open field can be converted into an area subject to Fourth Amendment protections. Obviously, houses and other buildings stand on what once was an open field. When a landowner takes substantial measures to exclude the public, such as construction of an exclusionary fence, as opposed to the insubstantial livestock fence that usually surrounds a field, it is at least arguable that he has a limited expectation of privacy in the enclosed area. Thus, for example, in United States v. FMC Corp., 428 F. Supp. 615 (W.D.N.Y. 1977), aff'd, 572 F.2d 902 (2d Cir. 1978), where the landowner surrounded a lagoon with an eight-foot high fence topped with barbed wire, the court concluded that he had a legitimate expectation of privacy of that lagoon. The correctness of this view is debatable. Even when surrounded by an exclusionary fence, a field is still a field -- and unmistakably remains not a person, house, paper, or effect. But even assuming that the fencing of a field at some point creates a constitutionally protected privacy interest that requires official intrusion to be reasonably justified, it does not follow that the field should be given the same constitutional protection as a home. That is, a search of such a field can be reasonable within the meaning of the Fourth Amendment even if not conducted pursuant to a warrant or based on probable cause. Because the privacy interest in a field, even if measures have been taken to exclude outsiders, does not approach the privacy interest in a home, a search of that field is a significantly lesser intrusion than a search of the home and correspondingly requires a lesser degree of justification. First, even a field surrounded by an exclusionary fence is subject to observation from the air and thus cannot be regarded as wholly private. /10/ Because the manner of observation is ordinarily of no consequence to the landowner, he has a limited legitimate expectation of preserving the privacy of things observable from the air. See United States v. Oliver, supra, slip op. 6 n.4. More important, the intrusion on the landowner's privacy when police enter a field is not even remotely comparable to the intrusion that is involved when police enter a home or business premises or search through private papers. In the case of a search of a private residence, if the police are mistaken in their suspicion of criminal activity, they unnecessarily disrupt the area tha people reserve for their most personal and private matters. The exposure of these matters to outsiders is a most severe intrusion into the privacy of the innocent individual. In order to safeguard these important privacy interests against unjustified invasion, the Fourth Amendment interposes two requirements before a home or office can be searched: the substantive requirement that the police have probable cause to believe that evidence of criminal activity will be found and the procedural requirement that this determination be made by a neutral and detached magistrate. If the police err in invading an open field, however, the consequences are much less severe. The entry is a minimal disruption of an individual's privacy. Exposure to the police of the contents of an open field is relatively unintrusive. In most cases, the consequence is simply that the police observe nothing but a field and perhaps some cornstalks or cows; an individual is highly unlikely to keep in an open field personal effects that he wishes to keep private. Because the invasion of privacy resulting from an erroneous search is substantially smaller in the case of a field than in the case of a residence, an office, or even an automobile, it is reasonable that the Fourth Amendment standard that must be satisfied before a search may occur be less severe. Suppose, for instance, that the police receive an anonymous tip that the body of a missing person is buried in the corner of a fenced wheat field or that a cache of automatic weapons is hidden in the woods inside a large, fenced farm. The tip affords a reasonable suspicion of unlawful activity but is insufficiently substantiated to provide probable cause, without which no warrant can be obtained. While the police could not rely on information of this quality to search a house, reason dictates that the information affords a sufficient basis to undertake a search implicating the comparatively inconsequential privacy interests in a field or woods. Accordingly, a rational balancing of societal and individual interests in this circumstance calls for allowing a search upon a justification that, while concrete and objectively verifiable, is less substantial than is needed to justify invasion of more private areas. This Court has recognized in other contexts that the two basic constitutional prerequisites to a search of a residence do not necessarily apply where there is a substantially reduced privacy intrusion. For example, a search of an automobile is a significantly lesser intrusion than a search of a residence. As the Court explained in United States v. Chadwick, 433 U.S. 1, 12 (1977), quoting Cardwell v. Lewis, 417 U.S. 583, 590 (1974) (plurality opinion): One has a lesser expectation of privacy in a motor vehicle because its function is transportation and it seldom serves as one's residence or as the repository of personal effects * * *. It travels public thoroughfares where both its occupants and its contents are in plain view. As a result, the warrant requirement is thought to be unnecessary to protect adequately the owner's privacy interests in the vehicle's interior. See also Arkansas v. Sanders, 442 U.S. 753, 761 (1979); Rakas v. Illinois, supra, 439 U.S. at 153-155 (Powell, J., concurring); South Dakota v. Opperman, 428 U.S. 364, 368 (1976). Even so, it is clear that the likelihood that personal effects will be found in a car (perhaps while in transit to or from a residence) /11/ is substantially greater than the likelihood that such personal effects will be found in an open field. /12/ Similarly, seizures that are a minimal intrusion compared to an arrest may be effected on less than probable cause. See, e.g., United States v. Cortez, 449 U.S. 411 (1981); United States v. Brignoni-Ponce, 422 U.S. 873 (1975); Terry v. Ohio, 392 U.S. 1 (1968). And in the context of administrative searches, where there is generally a reduced expectation of privacy (see Donovan v. Dewey, 452 U.S. 594, 598-599 (1981)), a search satisfies the "reasonableness" requirement of the Fourth Amendment despite absence of probable cause to believe that a violation will be found, even where a residence is involved. See Marshall v. Barlow's Inc., 436 U.S. 307, 320-321 (1978); Camara v. Municipal Court, 387 U.S. 523, 538 (1967). Given the extremely limited nature of the privacy intrusion involved in the search of a field, it is appropriate that such searches not be constrained by the strictest level of Fourth Amendment protection. There will be situations where the police receive information not amounting to probable cause that there is evidence of criminal activity in a field, such as a marijuana crop, but it would be difficult or impossible to investigate this suspicion further without entry onto the field. In light of the minimal adverse consequences that would occur from an entry if the information turns out to be erroneous, it is "reasonable" within the meaning of the Fourth Amendment, even if a field is surrounded by an exclusionary fence, to permit police to enter onto it on the basis of reasonable suspicion of criminal activity, rather than being forced to ignore the information they have received. See United States v. Johnson, 561 F.2d 832, 852-853 (D.C. Cir.) (MacKinnon, J., concurring), cert. denied, 432 U.S. 907 (1977); United States v. Knight, supra, 451 F.2d at 278. /13/ II. THE ENTRY ONTO RESPONDENT BRADY'S FIELD DID NOT VIOLATE THE FOURTH AMENDMENT Under the foregoing analysis, the applicability of Fourth Amendment constraints to a search of a field (if they are applicable at all) depends upon the measures taken by the landowner to safeguard his property. For example, in United States v. Oliver, supra, where the landowner did not restrict in any way access on foot to his property, the fact that he posted a "No Trespassing" sign plainly did not increase his expectation of privacy in his fields to the extent that the "open fields" doctrine should no longer apply. On the other hand, in United States v. FMC Corp., supra, the construction of an exclusionary fence topped with barbed wire arguably gave rise to a reasonable expectation of privacy. The facts set forth in the record indicate that this case falls somewhere between these two extremes. On the one hand, one of the surveillance teams actually cut the lock on a gate in order to gain access to respondent's property. While this destruction of property is not in itself a Fourth Amendment violation, /14/ the fact that an individual has taken measures that effectively prevent access to his field without the destruction of property is certainly probative of the degree of privacy that he is entitled to expect. In this case, however, it was not necessary to break the lock on the gate in order to enter the ranch; another surveillance team entered simply by climbing over the fence (J.A. 50, 55). Thus, respondent had not taken measures that would prevent outsiders from entering his farm except by breaking a lock; his legitimate expectation of privacy -- assuming arguendo that some could be had in farm fields -- must be measured by the easiest means of access to his ranch. See United States v. Oliver, supra, slip op. 6 n.4. The record states that the fence surrounding the Brady ranch was a "barbed-wire fence" (J.A. 33). That statement could describe an exclusionary fence or an ordinary perimeter livestock fence, which is typically made of barbed wire and does not present much of an obstacle to a person. See, e.g., State v. Stanton, supra, Giddens v. State, supra. The record indicates that, as would be expected of a fence surrounding a cattle ranch, the fence here was of the latter character, rather than designed to exclude outsiders. First, two of the police officers entered the field by climbing over the fence, apparently without much difficulty (see J.A. 50, 55). /15/ More significantly, respondent Brady himself testified that he had constant trouble with trespassers on his property -- cattle rustlers, poachers, and people who stole tires and batteries from vehicles on his property (R. 15-16). /16/ Thus, it does not appear that respondent Brady took such measures to exclude the public from his open field as might warrant recognition of a constitutionally protected expectation of privacy in that field. In any event, even if the fence surrounding the ranch here was sufficient to create a reasonable expectation of privacy, the police entry was justified by information that gave them reason to suspect criminal activity. /17/ They received information on two occasions that one or two planes carrying contraband would be landing at a location that the police deduced was the Brady ranch, and the information was somewhat detailed, specifying the radio frequency that would be used to turn on the runway lights and the call numbers of the planes. See Pet. App. A2-A3; J.A. 34-40. The State informs us that the source of that information was wiretaps (see Pet. Br. 57) /18/ and thus more reliable than an anonymous tip. While the information apparently did not specify the Brady property and thus probably fell short of probable cause, it appears to have given the police a substantial basis for suspicion, sufficient to warrant the limited privacy intrusion of entering onto the field. /19/ CONCLUSION The judgment of the Supreme Court of Florida should be reversed. Respectfully submitted. REX E. LEE Solicitor General D. LOWELL JENSEN Assistant Attorney General ANDRES L. FREY Deputy Solicitor General ALAN I. HOROWITZ Assistant to the Solicitor General KATHLEEN A. FELTON Attorney AUGUST 1982 /1/ The officers did not at any time approach the trailer or barn (J.A. 32-33, 46, 53). /2/ We note that although respondent Brady, the owner of the property, clearly was entitled to challenge the entry onto his own land as violative of the Fourth Amendment, there is no showing that the other four respondents had any connection with the property sufficient to support a Fourth Amendment claim. See Rakas v. Illinois, 439 U.S. 128 (1978). Because the "standing" question has not been raised in this case, however, it appears that the merits of the Fourth Amendment claim are before the Court even though the State has dismissed the charges against Brady. See Br. in Opp. 16. /3/ The curtilage is an area surrounding the house that is habitually used for family purposes. See Black's Law Dictionary 346 (5th ed. 1979). The common law recognized that the curtilage was not to be treated as a part of the house for some purposes (see 4 W. Blackstone, Commentaries ch. 16, at 225 (Univ. of Chicago Press ed. 1979)), and the Court in Hester cited to this common law rule. 265 U.S. at 59. Accordingly, it has been recognized that the open fields doctrine does not extend to the curtilage. See, e.g., United States v. Van Dyke, 643 F.2d 992, 993 (4th Cir. 1981); United States v. Williams, 581 F.2d 451, 453 (5th Cir. 1978), cert. denied, 440 U.S. 972 (1979); United States ex rel. Saiken v. Bensinger, 546 F.2d 1292, 1295-1297 (7th Cir. 1976), cert. denied, 431 U.S. 930 (1977); Care v. United States, 231 F.2d 22, 25 (10th Cir.), cert. denied, 351 U.S. 932 (1956). /4/ The Court in Katz noted that the issue involved there, because of significant scientific advances in the area of electronic surveillance and "the vital role that the public telephone has come to play in private communication," was one that could not specifically have been contemplated by the Framers or even by the Court in earlier years. See 389 U.S. at 352; id. at 362 (Harlan, J., concurring). No comparable technological advance provides any basis for affording a greater degree of Fourth Amendment protection to a field today than at the time Hester was cediced or when the Fourth Amendment protection of "persons, houses, papers, and effects" was first enacted. See United States v. Oliver, No. 80-5437 (6th Cir. May 5, 1982) (en banc), petition for cert. pending, No. 82-15 (filed July 2, 1982), slip op. 4. /5/ The conclusion that the Fourth Amendment is not violated when police trespass onto an open field does not suggest that a landowner is powerless to prevent such a trespass. As a practical matter, law enforcement officers likely will enter onto private property only if they have good reason to suspect that criminal activity is afoot. If, however, a landowner is being harassed by unjustified police entry onto his property, he can seek damages or an injunction prohibiting the police from further trespass, in accordance with remedies supplied by state law. /6/ Indeed, in at least two of the reported cases concerning the applicability of the open fields doctrine to a fenced field, law enforcement officers entered the field after the criminal activity was reported to them by members of the public who were trespassing on the property. See State v. Stanton, supra (two teenagers); State v. Byers, 359 So.2d 84 (La. 1978) (hunter). /7/ A fence, depending on its nature, may designate a particular area of a farm as more private, and a fence closely surrounding a residence may be an important factor in defining the curtilage. See, e.g., United States v. Van Dyke, supra, 643 F.2d at 994; United States v. Williams, supra, 581 F.2d at 454. But a boundary fence that surrounds a large farm does not convert all the open areas on the farm into areas protected by the Fourth Amendment. /8/ Numerous other decisions, not involving fields described as fenced or posted, also recognize the continuing vitality of the Hester open fields doctrine after Katz. See, e.g., Patterson v. National Transportation Safety Board, 638 F.2d 144 (10th Cir. 1980); United States v. Ramapuram, 632 F.2d 1149, 1155 (4th Cir. 1980), cert. denied, 450 U.S. 1030 (1981); United States v. Basile, 569 F.2d 1053 (9th Cir. 1978); United States v. Freie, supra; Patler v. Slayton, supra; United States v. Brown, 487 F.2d 208, 210 (4th Cir. 1973), cert. denied, 416 U.S. 909 (1974). /9/ Of course, there are areas outside the home that are sufficiently private to warrant Fourth Amendment protection. Thus, the courts have invalidated searches of enclosed structures or open areas that are part of the curtilage. See, e.g., United States v. Van Dyke, supra; United States v. Holmes, 521 F.2d 859 (5th Cir. 1975); Wattenburg v. United States, 388 F.2d 853, 857-858 (9th Cir. 1968). /10/ Aerial observation consistently has been held not to invade an expectation of privacy recognized under the Fourth Amendment. See, e.g., United States v. Allen, 633 F.2d 1282, 1289-1290 (9th Cir. 1980), cert. denied, No. 80-2125 (Oct. 5, 1981); United States v. Mullinex, 508 F. Supp. 512, 514-515 (E.D. Ky. 1980); United States v. DeBacker, 493 F. Supp. 1078, 1081 (W.D. Mich. 1980); People v. Lashmett, supra, 71 Ill. App. 3d at 431, 389 N.E.2d at 890; State v. Stachler, 58 Hawaii 412, 418-419, 570 P.2d 1323, 1327-1328 (1977); Dean v. Superior Court, 35 Cal. App. 3d 112, 117-118, 110 Cal. Rptr. 585, 589-590 (1973); but see People v. Sneed, 32 Cal. App. 3d 535, 542-543, 108 Cal. Rptr. 146, 150-151 (1973). /11/ Even if the personal effects are stored in the automobile in a container that indicates that it contains personal effects, they may be exposed by a warrantless search. See United States v. Ross, No. 80-2209 (June 1, 1982). /12/ Reduced expectations of privacy also justify warrantless administrative searches of pervasively regulated businesses. See Donovan v. Dewey, 452 U.S. 594, 598-602 (1981); United States v. Biswell, 406 U.S. 311, 316 (1972). /13/ Several courts have suggested that certain police investigative techniques that are more in the nature of searches than seizures implicate the protections of the Fourth Amendment, yet may be conducted based on a level of suspicion less than probable cause. See United States v. Beale, 674 F.2d 1327, 1334-1335 (9th Cir. 1982), petition for rehearing pending, No. 80-1652 (dog sniff); United States v. Michael, 645 F.2d 252, 258 (5th Cir. 1981) (en banc), cert. denied, No. 81-112 (Oct. 19, 1981) (beeper installation); United States v. Allen, supra, 633 F.2d at 1290 (helicopter surveillance); United States v. Curtis, 562 F.2d 1153, 1156 (9th Cir. 1977) (beeper installation); United States v. Johnson, 413 F.2d 1396, 1399-1400 (5th Cir. 1969), aff'd en banc, 431 F.2d 441 (1970) (inspection of automobile vehicle identification number). As explained in our petition in United States v. Knotts, cert. granted, No. 81-1802 (June 21, 1982), it is the government's view that installation of a beeper does not implicate any protected Fourth Amendment interest. Similarly, we do not necessarily agree that the other investigative techniques listed above implicate any constitutional protection. Nevertheless, we believe those courts have utilized a sound analytic framework in acknowledging that certain classes of searches, although subject to the Fourth Amendment, are reasonably justified when the police possess reasonable suspicion of criminal activity short of probable cause, but would be unreasonable if conducted on a random or suspicionless basis. /14/ The fact that the destruction of property that resulted from the entry does not violate the Fourth Amendment does not leave the property owner defenseless against such conduct. Presumably, he can bring a suit for damages to recover for any unjustified damage. See Conrad v. State, 63 Wis. 2d 616, 633 n.1, 218 N.W. 2d 252, 261 n.1 (1974). /15/ With proper equipment, of course, almost any fence can be "climbed over." A landowner who constructed a high wall to exclude outsiders would have a reasonable expectation of privacy even if police could use special ladders to scale the wall without damaging any property. But a fence that can be stepped over or easily climbed over without equipment, such as the ordinary livestock fence, cannot be considered an exclusionary fence giving rise to a legitimate expectation of privacy. /16/ "R." refers to the record on appeal in the Florida Fourth District Court of Appeal, No. 78-2121. /17/ It is noteworthy that the privacy intrusion here was even smaller than that which occurred in Hester. In Hester, the revenue officers entered onto the open field so as to be in position to observe activities occurring on the curtilage. Here, by contrast, the officers did not approach the residence or curtilage and could not observe anything that was not in the field itself. /18/ Because the record has not yet been lodged with this Court, we have not been able to verify this information independently. /19/ We emphasize again that, had the suspicions entertained by the police been unfounded, their activities would have produced a quet evening under the stars, but no likely exposure to any private effects of respondent Brady.