Officer Elliot came to suspect that "weed" was being grown in Kyllo’s home. The officer used thermal imagery to see if weed lamps were being used. The scan took a few minutes from the passenger seat of the police car.
•Based on the informants' utility bills, the thermal imagery the magistrate issued a warrant authorizing a search.
Issue: Are the officers on a public street engaging in more than naked-eye surveillance of a home?
•We do not know if there was probable cause.
•Obtaining by sense-enhancing technology any info regarding the interior of the home that could not otherwise have been obtained without physical intrusion into a constitutionally protected area constitutes a SEARCH
Government says: it only detects heat radiating from the external surface of the house
The observations were off the wall: the exterior of the home
It did not constitute a physical penetration into the premises