In a decision that limited the use of modern privacy-threatening technology, the Supreme Court held that police much have a search warrant in order to use a thermal imager to detect patterns of heat coming from a private home.
In 1992, federal agents aimed a sensitive heat detector, the Agema Thernovision 210, at Danny Kyllo’s home in Florence, Oregon. The agents were acting on the basis of tips and utility bills suggesting the possibility that Kyllo might be growing marijuana indoors under high-intensity lamps. After the instrument registered suspicious-looking hot spots, the agents obtained a warrant to enter and search the home, where they discovered more than one hundred marijuana plants growing under lamps. Although Kyllo agreed to plead guilty of a misdemeanor requiring one month in jail, he contested the validity of the search.
The Supreme Court, by a 5-4 margin, agreed with Kyllo’s contention that the warrantless use of the thermal imager had violated his “reasonable expectation of privacy.” Writing the opinion for the Court, Justice Antonin Scalia
The Kyllo ruling highlighted the unpredictable nature of the Court’s line drawing when applying Fourth Amendment principles. The previous year, in Bond v. United States
Privacy, right to
Search warrant requirement
Stevens, John Paul