Kyllo v. United States

United States Supreme Court

533 U.S. 27, 121 S.Ct. 2038, 150 L.Ed.2d 94 (2001)

 

In this case the Supreme Court considers whether the use of a thermal imager by law enforcement agents constitutes a “search” within the meaning of the Fourth Amendment. The facts are presented in Justice Scalia’s majority opinion.

 

Justice Scalia delivered the opinion of the Court.

 

… In 1991 Agent William Elliott of the United States Department of the Interior came to suspect that marijuana was being grown in the home belonging to petitioner Danny Kyllo. … Indoor marijuana growth typically requires high-intensity lamps. In order to determine whether an amount of heat was emanating from petitioners home consistent with the use of such lamps, at 3:20 a.m. on January 16, 1992, Agent Elliott and Dan Haas used an Agema Thermovision 210 thermal imager to scan the triplex. Thermal imagers detect infrared radiation, which virtually all objects emit but which is not visible to the naked eye. The imager converts radiation into images based on relative warmth.  Black is cool, white is hot, shades of gray connote relative differences; in that respect, it operates somewhat like a video camera showing heat images. The scan of Kyllo’s home took only a few minutes and was performed from the passenger seat of Agent Elliott’s vehicle across the street from the front of the house and also from the street in back of the house. The scan showed that the roof over the garage and a side wall of petitioners home were relatively hot compared to the rest of the home and substantially warmer than neighboring homes in the triplex. Agent Elliott concluded that petitioner was using halide lights to grow marijuana in his house, which indeed he was. Based on tips from informants, utility bills, and the thermal imaging, a Federal Magistrate Judge issued a warrant authorizing a search of petitioners home, and the agents found an indoor growing operation involving more than 100 plants. Petitioner was indicted on one count of manufacturing marijuana…. He unsuccessfully moved to suppress the evidence seized from his home and then entered a conditional guilty plea.

 

The Court of Appeals for the Ninth Circuit remanded the case for an evidentiary hearing regarding the intrusiveness of thermal imaging. On remand the District Court found that the Agema 210 is a non-intrusive device which emits no rays or beams and shows a crude visual image of the heat being radiated from the outside of the house; it did not show any people or activity within the walls of the structure; [t]he device used cannot penetrate walls or windows to reveal conversations or human activities; and [n]o intimate details of the home were observed. … Based on these findings, the District Court upheld the validity of the warrant that relied in part upon the thermal imaging, and reaffirmed its denial of the motion to suppress. A divided Court of Appeals initially reversed, … but that opinion was withdrawn and the panel (after a change in composition) affirmed, … with Judge Noonan dissenting. The court held that petitioner had shown no subjective expectation of privacy because he had made no attempt to conceal the heat escaping from his home, and even if he had, there was no objectively reasonable expectation of privacy because the imager did not expose any intimate details of Kyllos life, only amorphous hot spots on the roof and exterior wall. … We granted certiorari. …

 

…At the very core of the Fourth Amendment stands the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion. With few exceptions, the question whether a warrantless search of a home is reasonable and hence constitutional must be answered no. …

 

            On the other hand, the antecedent question of whether or not a Fourth Amendment search has occurred is not so simple under our precedent. The permissibility of ordinary visual surveillance of a home used to be clear because, well into the 20th century, our Fourth Amendment jurisprudence was tied to common-law trespass. …Visual surveillance was unquestionably lawful because the eye cannot by the laws of England be guilty of a trespass. … We have since decoupled violation of a persons Fourth Amendment rights from trespassory violation of his property, … but the lawfulness of warrantless visual surveillance of a home has still been preserved. As we observed in California v. Ciraolo … (1986), “[t]he 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.”

 

One might think that the new validating rationale would be that examining the portion of a house that is in plain public view, while it is a search despite the absence of trespass, is not an unreasonable one under the Fourth Amendment. … But in fact we have held that visual observation is no search at all perhaps in order to preserve somewhat more intact our doctrine that warrantless searches are presumptively unconstitutional. … In assessing when a search is not a search, we have applied somewhat in reverse the principle first enunciated in Katz v. United States … (1967). … As Justice Harlan’s oft-quoted concurrence described it, a Fourth Amendment search occurs when the government violates a subjective expectation of privacy that society recognizes as reasonable. … We have subsequently applied this principle to hold that a Fourth Amendment search does not occur even when the explicitly protected location of a house is concerned unless the individual manifested a subjective expectation of privacy in the object of the challenged search, and society [is] willing to recognize that expectation as reasonable. …

 

The present case involves officers on a public street engaged in more than naked-eye surveillance of a home. We have previously reserved judgment as to how much technological enhancement of ordinary perception from such a vantage point, if any, is too much. …

 

The Katz test whether the individual has an expectation of privacy that society is prepared to recognize as reasonable has often been criticized as circular, and hence subjective and unpredictable. … While it may be difficult to refine Katz when the search of areas such as telephone booths, automobiles, or even the curtilage and uncovered portions of residences are at issue, in the case of the search of the interior of homes the prototypical and hence most commonly litigated area of protected privacy there is a ready criterion, with roots deep in the common law, of the minimal expectation of privacy that exists, and that is acknowledged to be reasonable. To withdraw protection of this minimum expectation would be to permit police technology to erode the privacy guaranteed by the Fourth Amendment. We think that obtaining by sense-enhancing technology any information regarding the interior of the home that could not otherwise have been obtained without physical intrusion into a constitutionally protected area, … constitutes a search at least where (as here) the technology in question is not in general public use. This assures preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted. On the basis of this criterion, the information obtained by the thermal imager in this case was the product of a search.

           

            The Government maintains, however, that the thermal imaging must be upheld because it detected only heat radiating from the external surface of the house…. The dissent makes this its leading point, … contending that there is a fundamental difference between what it calls off-the-wall observations and through-the-wall surveillance. But just as a thermal imager captures only heat emanating from a house, so also a powerful directional microphone picks up only sound emanating from a house and a satellite capable of scanning from many miles away would pick up only visible light emanating from a house. We rejected such a mechanical interpretation of the Fourth Amendment in Katz, where the eavesdropping device picked up only sound waves that reached the exterior of the phone booth. Reversing that approach would leave the homeowner at the mercy of advancing technology including imaging technology that could discern all human activity in the home. While the technology used in the present case was relatively crude, the rule we adopt must take account of more sophisticated systems that are already in use or in development. The dissents reliance on the distinction between off-the-wall and through-the-wall observation is entirely incompatible with the dissents belief, which we discuss below, that thermal-imaging observations of the intimate details of a home are impermissible. The most sophisticated thermal imaging devices continue to measure heat off-the-wall rather than through-the-wall; the dissents disapproval of those more sophisticated thermal-imaging devices, … is an acknowledgement that there is no substance to this distinction. As for the dissents extraordinary assertion that anything learned through an inference cannot be a search, … that would validate even the through-the-wall technologies that the dissent purports to disapprove. Surely the dissent does not believe that the through-the-wall radar or ultrasound technology produces an 8-by-10 Kodak glossy that needs no analysis (i.e., the making of inferences). …

 

The Government also contends that the thermal imaging was constitutional because it did not detect private activities occurring in private areas…. The Fourth Amendments protection of the home has never been tied to measurement of the quality or quantity of information obtained. In Silverman, for example, we made clear that any physical invasion of the structure of the home, by even a fraction of an inch, was too much, … and there is certainly no exception to the warrant requirement for the officer who barely cracks open the front door and sees nothing but the nonintimate rug on the vestibule floor. In the home, our cases show, all details are intimate details, because the entire area is held safe from prying government eyes….

 

Limiting the prohibition of thermal imaging to intimate details would not only be wrong in principle; it would be impractical in application, failing to provide a workable accommodation between the needs of law enforcement and the interests protected by the Fourth Amendment. … To begin with, there is no necessary connection between the sophistication of the surveillance equipment and the intimacy of the details that it observes which means that one cannot say (and the police cannot be assured) that use of the relatively crude equipment at issue here will always be lawful. The Agema Thermovision 210 might disclose, for example, at what hour each night the lady of the house takes her daily sauna and bath, a detail that many would consider intimate; and a much more sophisticated system might detect nothing more intimate than the fact that someone left a closet light on. We could not, in other words, develop a rule approving only that through-the-wall surveillance which identifies objects no smaller than 36 by 36 inches, but would have to develop a jurisprudence specifying which home activities are intimate and which are not. And even when (if ever) that jurisprudence were fully developed, no police officer would be able to know in advance whether his through-the-wall surveillance picks up intimate details and thus would be unable to know in advance whether it is constitutional. …

 

We have said that the Fourth Amendment draws a firm line at the entrance to the house. … That line, we think, must be not only firm but also bright, which requires clear specification of those methods of surveillance that require a warrant. While it is certainly possible to conclude from the videotape of the thermal imaging that occurred in this case that no significant compromise of the homeowner’s privacy has occurred, we must take the long view, from the original meaning of the Fourth Amendment forward. …

 

Where, as here, the Government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a search and is presumptively unreasonable without a warrant. …

 

Justice Stevens, with whom The Chief Justice, Justice O’Connor, and Justice Kennedy join, dissenting.

 

There is, in my judgment, a distinction of constitutional magnitude between through-the-wall surveillance that gives the observer or listener direct access to information in a private area, on the one hand, and the thought processes used to draw inferences from information in the public domain, on the other hand. The Court has crafted a rule that purports to deal with direct observations of the inside of the home, but the case before us merely involves indirect deductions from off-the-wall surveillance, that is, observations of the exterior of the home. Those observations were made with a fairly primitive thermal imager that gathered data exposed on the outside of petitioners home but did not invade any constitutionally protected interest in privacy. Moreover, I believe that the supposedly bright-line rule the Court has created in response to its concerns about future technological developments is unnecessary, unwise, and inconsistent with the Fourth Amendment.

 

There is no need for the Court to craft a new rule to decide this case, as it is controlled by established principles from our Fourth Amendment jurisprudence. One of those core principles, of course, is that searches and seizures inside a home without a warrant are presumptively unreasonable…. But it is equally well settled that searches and seizures of property in plain view are presumptively reasonable. …Whether that property is residential or commercial, the basic principle is the same: What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. … That is the principle implicated here.

 

While the Court … decides this case based largely on the potential of yet-to-be-developed technology that might allow through-the-wall surveillance, … this case involves nothing more than off-the-wall surveillance by law enforcement officers to gather information exposed to the general public from the outside of petitioners home. All that the infrared camera did in this case was passively measure heat emitted from the exterior surfaces of petitioners home; all that those measurements showed were relative differences in emission levels, vaguely indicating that some areas of the roof and outside walls were warmer than others. As still images from the infrared scans show, … no details regarding the interior of petitioners home were revealed. Unlike an x-ray scan, or other possible through-the-wall techniques, the detection of infrared radiation emanating from the home did not accomplish an unauthorized physical penetration into the premises, … nor did it obtain information that it could not have obtained by observation from outside the curtilage of the house. …

 

Indeed, the ordinary use of the senses might enable a neighbor or passerby to notice the heat emanating from a building, particularly if it is vented, as was the case here. Additionally, any member of the public might notice that one part of a house is warmer than another part or a nearby building if, for example, rainwater evaporates or snow melts at different rates across its surfaces. Such use of the senses would not convert into an unreasonable search if, instead, an adjoining neighbor allowed an officer onto her property to verify her perceptions with a sensitive thermometer. Nor, in my view, does such observation become an unreasonable search if made from a distance with the aid of a device that merely discloses that the exterior of one house, or one area of the house, is much warmer than another. Nothing more occurred in this case.

 

Thus, the notion that heat emissions from the outside of a dwelling is a private matter implicating the protections of the Fourth Amendment (the text of which guarantees the right of people to be secure in their houses against unreasonable searches and seizures (emphasis added)) is not only unprecedented but also quite difficult to take seriously. Heat waves, like aromas that are generated in a kitchen, or in a laboratory or opium den, enter the public domain if and when they leave a building. A subjective expectation that they would remain private is not only implausible but also surely not one that society is prepared to recognize as reasonable. …

 

To be sure, the homeowner has a reasonable expectation of privacy concerning what takes place within the home, and the Fourth Amendments protection against physical invasions of the home should apply to their functional equivalent. But the equipment in this case did not penetrate the walls of petitioners home, and while it did pick up details of the home that were exposed to the public, … it did not obtain any information regarding the interior of the home. … In the Courts own words, based on what the thermal imager showed regarding the outside of petitioners home, the officers concluded that petitioner was engaging in illegal activity inside the home. … It would be quite absurd to characterize their thought processes as searches, regardless of whether they inferred (rightly) that petitioner was growing marijuana in his house, or (wrongly) that the lady of the house [was taking] her daily sauna and bath. … In either case, the only conclusions the officers reached concerning the interior of the home were at least as indirect as those that might have been inferred from the contents of discarded garbage, … or pen register data, … or, as in this case, subpoenaed utility records. … For the first time in its history, the Court assumes that an inference can amount to a Fourth Amendment violation. …

 

            Since what was involved in this case was nothing more than drawing inferences from off-the-wall surveillance, rather than any through-the-wall surveillance, the officers conduct did not amount to a search and was perfectly reasonable. …

 

Although the Court is properly and commendably concerned about the threats to privacy that may flow from advances in the technology available to the law enforcement profession, it has unfortunately failed to heed the tried and true counsel of judicial restraint. Instead of concentrating on the rather mundane issue that is actually presented by the case before it, the Court has endeavored to craft an all-encompassing rule for the future. It would be far wiser to give legislators an unimpeded opportunity to grapple with these emerging issues rather than to shackle them with prematurely devised constitutional constraints. …