Academic journal article Michigan Law Review

Fourth Amendment Textualism

Academic journal article Michigan Law Review

Fourth Amendment Textualism

Article excerpt


"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated . ..

- United States Constitution, Amendment IV

The Fourth Amendment prohibits unreasonable "searches" and "seizures." This places the Supreme Court's definition of the term "search" at the center of the always-evolving balance between privacy and security. Technological advances offer the government a steady stream of novel investigative techniques, but only those that qualify as "searches" (or "seizures"1) trigger Fourth Amendment protections.2

Ever since the 1967 case Katz v. United States, the Supreme Court has framed the "is-it-a-search?" inquiry by asking whether the police invaded the complaining party's "reasonable expectation of privacy."3 Scholarly commentary on this doctrine kills more trees than termites. Yet despite all the attention, the "reasonable expectation of privacy" test remains "the central mystery of Fourth Amendment law"; "no one seems to know what makes an expectation of privacy constitutionally 'reasonable.' "4

The Katz test's indeterminacy was on display in the Supreme Court's latest Fourth Amendment "blockbuster."5 In Carpenter v. United States, police obtained records containing "cell-site location information (CSLI)" from two wireless carriers.6 The records revealed Timothy Carpenter's location in the vicinity of a series of robberies in downtown Detroit.7 Precedent suggested this was not a "search." The Supreme Court had previously held that there was no reasonable expectation of privacy in (1) information obtained from third parties8 or (2) one's location in public areas.9 Highlighting "the unique nature of cell phone location information," however, the Court ruled (5-4) that the government "invaded Carpenter's reasonable expectation of privacy."10 Consequently, "accessing seven days of CSLI constitutes a Fourth Amendment search."11 No principle emerges from the opinion (seven days?), or the laundry list of related scenarios where the Court cautioned that its analysis might not apply.12 Instead, the justices in the majority emphasized the need to "tread carefully" to "ensure that we do not 'embarrass the future.' "13 The present gets no such reprieve.

The irony of the Supreme Court's modern "search" jurisprudence is that the "reasonable expectation of privacy" test was supposed to avoid making "a crazy quilt of the Fourth Amendment."14 And yet here we are: "[A] fourth amendment with all of the character and consistency of a Rorschach blot."15 Extending the trendline into the future, there will be a line of cases for each "unique" technology and product: cell phones, GPS tracking, facial recognition, license plate readers, Alexa, Fitbit, and on and on. Reasoning by decree in a case or two each year, the Court will label applications of some technologies "searches," leave others unrestricted as "non-searches," and never opine on the rest. For the vast majority of potential search scenarios (six days of cell-site location information?), lower courts, citizens, and the police will be left guessing about what the Constitution permits.16

Despite its widely recognized indeterminacy, the "reasonable expectation of privacy" test endures. The best explanation for its longevity is a lack of viable alternatives.17 Judges and scholars rarely posit new formulations for defining a Fourth Amendment "search." Instead, reform proposals generally accept the Katz formula as an "inevitable first step in the direction of administrability"18 and seek to either cleanse the analysis of its perceived failings19 or incorporate new factors.20 Some scholars advocate making the Katz test even more pliable so the Court can focus on the central policy question, "how best to regulate government information gathering."21 The few efforts to dispense with Katz, like a recent proposal that ties searches and seizures to violations of "positive law,"22 promise as much complexity and uncertainty as Katz itself. …

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