Document Type
Brief
Publication Date
8-14-2017
Abstract
Amici are professors (identified in the Appendix) whose research and teaching include the Fourth Amendment, empirical analysis of the criminal justice system, and, specifically, empirical analyses of the public's "reasonable expectations." They file this brief to urge this Court to reverse the Sixth Circuit, recognize that the Fourth Amendment governs the inquiry here, and find that authorities violate the Fourth Amendment when law enforcement collect cell site location data without first obtaining a warrant.
The Court has recognized that public expectations of privacy are relevant to the Fourth Amendment. A growing body of social science research shows that a majority of people: (1) do not knowingly convey their location information to cell phone providers; and (2) believe that law enforcement needs to obtain, and ought to obtain, a search warrant before gathering this information. These studies addressed a range of surveilled information (cell site location and GPS tracking) and conduct (by cell phone providers and by law enforcement). On average across all the studies more than 60% of survey respondents (and often upwards of 70-80%) emphatically asserted a privacy interest in the information contained on or emitted from their cell phones. In relative terms, these privacy interests are as strong, or stronger, than paradigmatic cases where the Court has required law enforcement officials to first obtain a warrant.
These empirical data, detailed below, expressly undercut the Sixth Circuit's reliance on the third party doctrine in deciding this case, and affirmatively support a finding that warrantless searches of this information violate the Fourth Amendment. This Court should employ these empirical data -a critical tool that informs the proper scope and functioning of the Fourth Amendment- and reverse the decision below.
Recommended Citation
Prescott, J. J., "Carpenter v. United States: Brief of Amici Curiae Empirical Fourth Amendment Scholars in Support of Petitioner" (2017). Appellate Briefs. 34.
https://repository.law.umich.edu/briefs/34
Comments
Amicus: Chao, Professor Bernard; Farrell, Professor Ian; Fischer, Professor Ryan G. Ph.D.; Fradella, Professor Henry F. Ph.D.; Hoofnagle, Professor Chris Jay; Kugler, Professor Matthew B. Ph.D.; Prescott, Professor J.J. Ph.D.; Robertson, Professor Christopher; Slobogin, Christopher; Scott-Hayward, Professor Christine Ph.D.; Smith, Professor Alisa Ph.D.; Starr, Professor Sonja; Strahilevitz, Professor Lior; Tokson, Professor Matthew; Urban, Professor Jennifer M.