The Supreme Court: Finding Marijuana with Thermal-Imaging Devices

Finding Marijuana with Thermal-Imaging Devices

A much more controversial drug case ruling decided by a 5 to 4 split on February 20, 2001, was Kyllo v. United States. The controversy surrounded the use of a thermal-imaging device to scan a residence for heat emissions.

Federal agent William Elliot suspected Danny Kyllo was growing marijuana in his home. Many people growing marijuana use high intensity heat generating lamps to facilitate its growth. Elliot parked his car across from Kyllo's home and aimed a thermal imager at the house to see if the heat emanating from Kyllo's home was consistent with readings that would be expected if these high intensity lamps were being used.

Elliot conducted the scan at 3:20 A.M. and took just a few minutes to find out that the garage roof and one wall of the house were hotter than the rest of the house as well as the houses of his neighbors.

Just the Facts

Federal agent William Elliot used a device that is widely available to the general public—an Agema Thermovision 210. Thermal-imaging devices detect infrared radiation, which is emitted by almost all objects, but is not visible to the naked eye.

Using this information, as well as the information from an informant and Kyllo's subpoenaed utility, Elliot got a search warrant to search Kyllo's home. The search revealed over 100 marijuana plants under the cultivation of high-intensity lamps as the imager showed. Kyllo tried to suppress the evidence, which was denied by the district court. Kyllo entered a conditional guilty plea and appealed his case to the 9th Circuit Court.

The 9th Circuit Court ruled that the district court should hold a hearing on whether the use of the thermal imager was intrusive and violated Kyllo's Fourth Amendment rights. The district court found the imager was non-intrusive, gave a crude visual image of heat being radiated from the outside of the house, did not show any people or activity in the house, and could not penetrate the walls or windows. Therefore no intimate details had been revealed by the scan. The 9th Circuit Court affirmed that Kyllo's rights had not been denied because of an unconstitutional search and seizure.

Living Laws

Police cannot use an electronic device that would explore the details of your home without first getting a search warrant.

Kyllo then appealed the case to the United States Supreme Court. In a 5 to 4 decision, the Supreme Court found that to “explore the 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 Scalia wrote the opinion for the Court and was joined by Breyer, Ginsburg, Souter and Thomas. Justice Stevens dissented and was joined by Rehnquist, Kennedy, and O'Connor.

In writing the opinion for the court, Justice Scalia said:

  • “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. While we upheld enhanced aerial photography of an industrial complex in Dow Chemical, we noted that we found 'it important that this is not an area immediately adjacent to a private home, where privacy expectations are most heightened.' …
  • “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 home-owner'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.
  • “Since we hold the Thermovision imaging to have been an unlawful search, it will remain for the district court to determine whether, without the evidence it provided, the search warrant issued in this case was supported by probable cause—and if not, whether there is any other basis for supporting admission of the evidence that the search pursuant to the warrant produced.”

The case was sent back to the district court for a ruling on whether the other information used to attain the search warrant was sufficient to try Kyllo. Justice Paul Stevens dissented from this ruling and was joined by Chief Justice Rehnquist, Kennedy and O'Connor. In his dissent, Stevens said:

  • “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 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 Amendment's 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 petitioner's 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 Court's own words, based on what the thermal imager 'showed' regarding the outside of petitioner's 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, 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 …
  • “Notwithstanding the implications of today's decision, there is a strong public interest in avoiding constitutional litigation over the monitoring of emissions from homes, and over the inferences drawn from such monitoring. Just as 'the police cannot reasonably be expected to avert their eyes from evidence of criminal activity that could have been observed by any member of the public' … so too public officials should not have to avert their senses or their equipment from detecting emissions in the public domain such as excessive heat, traces of smoke, suspicious odors, odorless gases, airborne particulates, or radioactive emissions, any of which could identify hazards to the community. In my judgment, monitoring such emissions with 'sense-enhancing technology' … and drawing useful conclusions from such monitoring, is an entirely reasonable public service.”

At least for now, use of new technology to scan your home is not constitutional, but given the closeness of this ruling this could change in a future Court.

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Excerpted from The Complete Idiot's Guide to The Supreme Court © 2004 by Lita Epstein, J.D.. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.