Kyllo v. U.S.

Citation: Kyllo v. United States, 533 U.S. 27 (2001).

Factual Background
Kyllo involved the government’s use of thermal imaging to discern heat differentials inside the home.

U.S. Supreme Court Proceedings
The Supreme Court ultimately determined that the use of thermal imaging was a search as defined by the Fourth Amendment; however, the Court made clear that looking into a home with the naked eye from a lawful vantage point may not be a search (e.g., police on the sidewalk looking into the home through a picture window).

The Court went further to state that it is not a search if the police use technology to duplicate what the police would see if standing on the sidewalk. The Court added that if technology “in general public use” is used to see more than the naked eye (e.g., telescope, binoculars, etc.) then it is not a search. “General public use” was further defined as that which is generally available to the public.