Officers suspected the defendant of growing marijuana in his home. They used a thermal-imaging device to determine if the amount of heat emanating from his home was consistent with the high-intensity lamps typically used for indoor marijuana growth. The scan of the defendant’s home took a few minutes and was performed from the passenger seat of an officer’s vehicle. The scan showed that the house was warmer than neighboring homes. The officers obtained a search warrant, in part based on this information.
Whether the use of a thermal-imaging device to detect levels of heat is a search under the Fourth Amendment?
Yes. Employing technology that is not used by the general public to obtain information about a home’s interior that could not have been obtained without physical entry constitutes a search.
The government argued that the scan only detected heat radiating from the home and that it did not detect “intimate details.” The government also argued that the defendant had not shown an expectation of privacy because he made no attempts to conceal the heat escaping from his home. The Court held that any information of a home that cannot be obtained except through either physical entry or sophisticated technology not readily available to the public is considered “intimate details.” In this case, the surveillance was a search and a warrant was needed to engage in the scan.
533 U.S. 27, 121 S. Ct. 2038 (2001)