Kyllo v. United States, 533 U.S. 27, 121 S. Ct. 2038, 150 L. Ed. 2d 94 (2001)
Author: Seth

Facts: Agent William Elliot of the United States Department of the Interior came to suspect that marijuana was being grown in the home belonging to Danny Kyllo. Indoor marijuana growth typically requires high-intensity lamps. In order to determine whether an amount of heat was emanating from petitioner’s home consistent with the use of such lamps, at 3:20 a.m. on January 16,th 1992, the agents used an Agema Thermovision 210 thermal imager to scan the home of Kyllo. 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 eat images. The scan of Kyllo’s home was performed from the passenger seat of Agent Elliott’s vehicle located across the street from the front of the house and also from the street in back of the hose. The scan showed that the roof over the garage and a side wall of Kyllo’s home were relatively hot compared to the rest of the home and substantially warmer than neighboring homes. Based on tips from informants, utility bills, and the thermal imaging, a Federal Magistrate Judge issued a warrant authorizing a search of petitioner’s home, and the agents found an indoor growing operation involving more than 100 plants.

Procedural Posture: Kyllo 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.
Court of Appeals for the Ninth Circuit: remanded the case for an evidentiary hearing regarding the intrusiveness of thermal imaging.
District Court: Upon appealfound that Agema 210 is a non-intrusive device and upheld the validity of the warrant and reaffirmed its denial of the motion to suppress
Court of Appeals for the Ninth Circuit: Held that Kyllo had shown no subjective expectation of privacy because he had made no attempt to conceal the heat escaping from his home.

Issue(s): Whether the use of a thermal-imaging device aimed at a private home from a public street to detect relative amounts of heat within the home constitutes a “search” within the meaning of the Fourth Amendment?

Judgment/Disposition: Reverse and remanded

Holding: The court held that the government’s use of using a thermal-imaging device constituted an unlawful search in violation of the Fourth Amendment.

Majority: Justice Scalia, who wrote the majority opinion, held that a person has a reasonable expectation of privacy, especially in the home, since that it was that Fourth Amendment was adopted to protect. He rejected the government’s argument that thermal-imaging must be upheld because it detected “only heat radiating from the external surface of the house” and also that thermal-imaging was constitutional because it did not “detect private activities occurring in private areas”. Scalia rejected this on the basis that new technology can very well impede into the lives of citizens. He wrote “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’”. He further held that the court could not develop a rule which determines what activities inside the home are “intimate” and which are not. Moreover, he wrote 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.

Other Resources: