Is the use of thermal imaging considered a search?

The use of thermal imaging is considered a search because it can reveal details about what is happening within a structure that would otherwise be invisible without physical entry. This technology allows law enforcement to detect heat emissions, which can indicate activities taking place inside a building, such as the presence of people or the operation of appliances. This capability exceeds what is typically observable from public spaces without intrusive methods, thus implicating the Fourth Amendment protection against unreasonable searches.

The legal framework established by various court rulings, particularly the U.S. Supreme Court decision in Kyllo v. United States, underlines that using a thermal imaging device constitutes a search because it involves an invasion of privacy that requires a warrant or probable cause. Therefore, the use of thermal imaging is held to the same standard as other investigative techniques that intrude upon an individual's reasonable expectation of privacy.