News Release

Nation's Criminal Defense Bar Applauds U.S. Supreme Court Decision in Carpenter

Washington, DC (June 22, 2018) – This morning, the U.S. Supreme Court issued its decision in Carpenter v. United States (16-402). The question presented in Carpenter was “whether the warrantless seizure and search of historical cell phone records revealing the location and movements of a cell phone user over the course of 127 days is permitted by the Fourth Amendment?” In a 5-4 decision authored by Chief Justice Roberts and joined by Justices Ginsburg, Breyer, Sotomayor, and Kagan, the Court held that the Government’s acquisition of Carpenter’s cell-site records was a Fourth Amendment search and therefore generally requires a warrant.

"Today's decision takes into account the 'seismic shifts' in technology and provides hope that privacy rights will survive in the digital age," said NACDL President Rick Jones.

"The Court’s message is clear: digital is different," said NACDL’s Fourth Amendment Center Senior Litigation Counsel and Co-Author of NACDL’s joint amicus brief Michael Price. "In declining to extend the ‘third-party doctrine’ to cell phone location records, the Court recognizes that data generated by new technologies may be an ‘entirely different species’ of information that demands Fourth Amendment protection."

The National Association of Criminal Defense Lawyers (NACDL), together with the Electronic Frontier Foundation, Brennan Center for Justice, Constitution Project, and National Association of Federal Defenders, filed a joint amicus brief in support of the petitioner in Carpenter. In that brief, amici argued that: (i) there has been a dramatic increase in location data generated by cell phones, collected by third parties, and routinely obtained by law enforcement without a warrant, (ii) Cell Site Location Information (CSLI) paints a revealing portrait of a person's movements, presenting even greater privacy concerns than the GPS tracker at issue in Jones, and (iii) the “third-party doctrine” is "ill-suited to the digital age" and should not apply to CSLI.

To learn more about NACDL's extensive work in the Fourth Amendment arena, visit

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Ivan Dominguez, NACDL Director of Public Affairs and Communications, (202) 465-7662 or 

The National Association of Criminal Defense Lawyers is the preeminent organization advancing the mission of the criminal defense bar to ensure justice and due process for persons accused of crime or wrongdoing. A professional bar association founded in 1958, NACDL's many thousands of direct members in 28 countries – and 90 state, provincial and local affiliate organizations totaling up to 40,000 attorneys – include private criminal defense lawyers, public defenders, military defense counsel, law professors and judges committed to preserving fairness and promoting a rational and humane criminal legal system.