growing marijuana

For Kyllo, the result was tremendous -- the charges against him were dropped because the police could not sustain the charges without the evidence of his growing operation. Faced with clear legal authority requiring them to obtain a warrant before engaging in future thermal imaging operations, law enforcement presumably now incorporate this requirement into their drug interdiction operations.

Facts and Procedural History

In 1991, Agent William Elliot of the Department of the Interior came to suspect that Danny Lee Kyllo was growing marijuana in his home in Florence, Oregon. Well before dawn on January 16, 1992, Elliot and a partner were seated in his car outside Kyllo's home, armed with a thermal imaging device. The device detects the emanation of heat based on relative differences. Because an indoor marijuana growing operation requires artificial light, which generates a lot of heat, Elliot suspected that the thermal imaging scan would reveal the evidence he needed, which indeed it did. Based on that evidence, and on evidence that Kyllo was using a large amount of electricity, a federal magistrate judge issued a warrant to search his apartment. Inside the apartment, agents found more than 100 marijuana plants.

Kyllo was charged with growing marijuana in violation of federal law. He asked the district court to suppress the marijuana because the thermal imaging had been performed without a warrant. The district court disagreed. Kyllo pleaded guilty but reserved the right to appeal the suppression decision. The Ninth Circuit remanded the case for a hearing about the intrusiveness of the thermal imaging device. Evidence was presented at the hearing that reflected the limited capabilities of the thermal imaging device -- it could reveal heat or cold, but not the presence or absence of people within the structure or conversations between those people. The district court upheld the search, and Kyllo appealed again. The Ninth Circuit affirmed, reasoning that Kyllo had no objectively reasonable expectation of privacy in the heat radiating from his home. Kyllo asked the Supreme Court to review his case, and it agreed to do so.

Majority opinion

For Justice Scalia, the home is a privileged place under Fourth Amendment law, because it is there that a person may freely retreat and be free from government interference. The Fourth Amendment protects people from unreasonable searches of their homes, after all.

The question of what constitutes a search for Fourth Amendment purposes, however, is remarkably difficult to answer. Historically, the meaning of a search depended on the common-law notion of trespass; after all, "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." Visual inspections are not "searches," and thus the Fourth Amendment allows police officers passing by a home on the sidewalk to peek inside a home through a window without violating the Fourth Amendment. Under this rationale, the Court has even upheld visual surveillance from the air above a suspect's property as not exceeding the bounds of the Fourth Amendment. On the other hand, enhancing the human senses with technology puts the Fourth Amendment analysis in a different light. In Katz v. United States, 389 U.S. 347 (1967), the Court held that evidence obtained by eavesdropping on a telephone booth with an electronic listening device violated the Fourth Amendment.

Consistent with his jurisprudential philosophy, Scalia recast this case history in terms of traditional understandings of privacy. "While it may be difficult to refine Katz when the search of areas such as telephone booths, automobiles, or even the curtilages 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." That criterion is physical intrusion. Using technology to obtain information one would otherwise need to physically intrude into the home in order to obtain is a search within the meaning of the Fourth Amendment. "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 unavailable without physical intrusion, the surveillance is a 'search' and is presumptively unreasonable without a warrant."

Thus, a search is a search because it requires a physical intrusion, not because of the quality of information it reveals. The thermal imaging device in this case could reveal "at what hour each night the lady of the house takes her daily sauna and bath." Since Scalia's goal was to realign this area of Fourth Amendment law with its original understanding, there could be no distinguishing the kinds of information various kinds of information could reveal. "The people in their houses, as well as the police, deserve more precision."

Dissent

Justice Stevens made the obvious rejoinder -- the thermal imaging device, because it passively measures only heat emanating from a structure, does not physically intrude the home and thus does not constitute a "search" even under the rule Scalia articulated. Under the Court's modern jurisprudence, things that a person knowingly exposes to the public are not the subject of Fourth Amendment protection. People are aware that heat can emanate from their homes; this is why they open windows when they are warm. Passersby can notice this heat -- particularly in winter in some places, where snow may melt more quickly over some parts of the home than over others. "Thus, the notion that heat emissions from the outside of a dwelling is a private matter implicating the protections of the Fourth Amendment is not only unprecedented by also quite difficult to take seriously." The thermal imaging device in this case merely showed that there was excess heat emanating from Kyllo's home; the officers had to use independent analysis to conclude that the source of that heat was a marijuana growing operation. And if Kyllo did not want the heat to escape, he could have insulated his home better.

Stevens argued that the Court's rule -- based on physical intrusion rather than things exposed to public view -- was intended to "provide essential guidance for the day when more sophisticated systems gain the ability to see through walls and other opaque barriers." By linking the protection of the rule to whether the technology at issue, Stevens complained, "the threat to privacy will grow, rather than recede, as the use of intrusive equipment becomes more readily available." Moreover, the category of technology embraced by the rule was too broad. Stevens feared it would invalidate a mechanical equivalent of the drug-sniffing dog. "If it takes sensitive equipment to detect an odor that identifies criminal conduct and nothing else, the fact that the odor emanates from the interior of a home should not provide it with constitutional protection."

External links

• Text of the opinion from LII, Cornell University
• Text of the opinion from findlaw.com
• Background from the OYEZ project, Northwestern University
• Transcript of oral argument
• Brief of the Solicitor General
• Amicus brief of the ACLU
• Danny Lee Kyllo's Homepage