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Criminal Justice Sciences


Michael Gizzi

Mentor Department

Criminal Justice Sciences


This project is focused on the judicial impact of a United States Supreme Court decision in Carpenter v US (2018), which modified the judicially created “third party doctrine,” that allows law enforcement to seek information from third parties (banks, phone companies, internet providers, etc.) without the use of a search warrant. The third-party doctrine is based on the principle that when an individual conducts business with a business or organization, like a phone company or bank, they have no privacy interest in the transaction records of the user. As a result, they cannot make a claim of protection under the Fourth Amendment to the Constitution against “unreasonable searches and seizures” and government officials are not required to seek a warrant. The third-party doctrine has become a routine tool by police as a way to gain evidence. In Carpenter, the Supreme Court limited the government’s ability to conduct warrantless searches involving law enforcement requests to cell phone providers to deliver “cell site location information” (CSLI) for specific phones. These records provided a detailed set of breadcrumb information as to the location of a user’s cell phone. The Court held that the privacy interests were so significant that the third-party doctrine would not be applied to this type of request. This study uses legal decisions from litigated cases since 2018 to better understand the scope of third-party usage by law enforcement, focuses on both the primary question of how case outcomes have changed as a result of the Carpenter decision and a broader question of better understanding the population of cases utilizing the third-party doctrine; with additional examinations of criminal investigations involving third-party doctrine requests and what types of third-party doctrine tools were used. A qualitative content analysis was conducted of 231 decisions of criminal cases that involved varying crimes, including: homicide, armed robbery, sexual misconduct, drugs, property, etc. In these cases, law enforcement were able to obtain defendant information utilizing CSLI data, camera surveillance, IP addresses, bank records, subscriber information, GPS, as well as through a variety of other software and databases. Many cases have concluded that law enforcement’s obtained evidence was subject to inclusion through the good-faith exception, resulting in many case decisions being upheld, much of which has opened numerous concerns for future defendants, such as with drug offenses, where CSLI may be obtained despite the existing precedent generated through Carpenter if attained in good-faith.


Authors: Alena Harm and Michael Gizzi

Privacy Concerns In The Digital Era: An Analysis Of The Third-Party Doctrine's Usage In The Criminal Court System