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Kyllo v. United States

From lawbrain.com

Kyllo v. United States, 533 U.S. 27 (2001), was a criminal procedure case heard by the United States Supreme Court that dealt with the constitutionality of a warrantless search of a home through use of a heat imaging device.

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Summary of Case Facts

Law enforcement suspected that the defendant, Kyllo, was growing large quantities of marijuana in his home. Because indoor marijuana growth requires a significant amount of light, which produces heat, the Department of the Interior used a thermal imaging device to scan the house to view the amount of heat radiating from the exterior of Kyllo’s home. From the scan they determined that a large amount of heat was radiating from Kyllo’s garage as compared to the rest of his home. This information was used as the basis to obtain a search warrant to enter Kyllo’s home where a large growing operation consisting of over one hundred marijuana plants was discovered. Kyllo appealed his conviction on the grounds that the thermal imaging scan of his home constituted a warrantless search of his home under the Fourth Amendment.


Does a thermal imaging scan of a home from a public vantage point to detect amounts of heat, which does not allow sight or listening into the home, constitute a search under the Fourth Amendment?

Holding and Law

Yes. The court determined that the use of the thermal imaging device without a warrant was an unconstitutional search of Kyllo’s home. The court opined that there is one has an overriding expectation of privacy in his or her home, and that even a scan of a home using technology that doesn’t physically enter a home can be tantamount to an unreasonable search. As the thermal imaging device used to scan the home was not readily available to the general public, the device’s use in such a “search” was presumptively unreasonable, and thus, unconstitutional. The majority opinion sought to create a firm, bright line at a home’s entrance, intended to protect against all types of warrantless surveillance.

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