Search

Historically, a “search” entailed some type of government invasion into a “constitutionally protected area.”15 Early courts looked to the enumerated areas described in the Fourth Amendment to determine what was a “constitutionally protected area” (i.e., “persons, houses, papers, and effects”).16 These courts soon began to emphasize property principles in their Fourth Amendment analysis.17 Not until the landmark decision of Katz v. United States in 1967 did the Supreme Court abandon its structural “property” approach for a fluid constitutional framework that was to “protect people, not places.”18

Katz involved eavesdropping by means of an electronic surveillance device attached to the exterior of a public telephone booth — a location not within the enumerated constitutional protections (i.e., persons, houses, papers, and effects). The lower courts concluded that no search took place since the electronic surveillance device did not penetrate the wall of the telephone booth. The Supreme Court, however, stepped away from its historical property principles and proclaimed that the reach of the Fourth Amendment could not turn upon the presence or absence of a physical intrusion into a given enclosure. Although the majority in Katz demonstrated a new understanding of the term “search,” it was Justice Harlan’s concurring opinion that articulated the basic standard courts emphasize today.

According to Justice Harlan’s concurrence, a “search” does not occur for purposes of the Fourth Amendment unless (1) the individual manifested a subjective expectation of privacy in the searched object and (2) society is willing to recognize that expectation as reasonable or legitimate.19 In essence, an impermissible “search” occurs when there is an infringement of an expectation of privacy that society is prepared to consider reasonable. Legitimate expectations of privacy must have a source outside of the Fourth Amendment, either by reference to concepts of real or personal property law or to understandings that are recognized and permitted by society.20 Among the factors to be considered in determining whether a defendant had a legitimate expectation of privacy in addition to the proprietary or possessory interest in the place to be searched, are (1) whether the defendant has the right to exclude others from the place in question; (2) whether he has exhibited a subjective expectation that the area would remain free from governmental intrusion; and (3) whether he was legitimately on the premises.21

In an effort to detect and search increasingly sophisticated smugglers, officials today have begun to rely more heavily on advanced technologies that seemingly intrude into our daily lives, often without our knowledge. The use of such devices may blur the line between expectations of privacy that are legitimate and those that are not. The Supreme Court addressed this issue in Kyllo v. United States when it considered the constitutional limits upon the government’s use of sensory-enhancing technology.22 The Kyllo Court determined that the use of a thermal-imaging device to detect heat waves emitted from a home was a “search” partly because all details in the home are intimate (i.e., a person has a subjective and reasonable expectation of privacy in the interior of his home).23 As a result, the Court held that where the government uses a device that is not in general public use, to explore details of the home or a “constitutionally protected area” that would previously have been unknowable without physical intrusion, the surveillance is a “search” and is presumptively unreasonable without a warrant.24 The Court felt that the Fourth Amendment was to be construed in the light of what was deemed an unreasonable search and seizure when it was adopted,25  but nonetheless, opined that it would “be foolish to contend that the degree of privacy secured to citizens by the Fourth Amendment has been entirely unaffected by the advance of technology.”26