Can the Police Now Use Thermal Imaging Devices Without a Warrant?

As these devices slowly migrate into the public's hands, you can be certain that these tools will be used by citizens to focus on ways to get actual evidence to request a warrant from the police, but the courts for now have banned the use of these tools to qualify for a search independently.

In Kyllo, the police used an infrared thermal imaging device called an “Agema Thermovision 210″ to scan a suspect’s home from the city street. The scan tool a few minutes, and it revealed that the roof over Kyllo’s garage was unusually hot — a sign, the government though, that the suspect was growing marijuana under heat lamps in the garage attic. The Supreme Court announced the following rule: “when . . . the Government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a “search” and is presumptively unreasonable without a warrant.” Because infrared temperature sensing was not in “general public use,” the thermal imaging was a “search” that required a warrant.