Carpenter v. U.S. Part 1 – Brief Overview of the Case Below

The Petitioner’s initial brief in Carpenter v. U.S. has been filed with the Supreme Court. The appeal involves law enforcement’s warrantless acquisition of historical cell site location information, and presents a single question for the Court: 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. The date for oral argument has not been set.

In the case below, Timothy Carpenter was arrested and accused of helping commit a string of armed robberies of Radio Shacks and T–Mobile stores in and around Detroit. To build a case against Carpenter, Federal Bureau of Investigation agents obtained transactional records from various wireless carriers using a 2703(d) “articulable facts” court order pursuant to the Stored Communications Act. The FBI was able to obtain 127 days of historical cell site location information for Carpenter from MetroPCS, Carpenter’s wireless service provider.

In a pre-trial motion, Carpenter moved to suppress the cell site location information, arguing that the FBI was required to first obtain a search warrant. His motion was denied. A key piece of evidence presented at trial was a map created by the FBI using historical cell site location data which showed that the location of Carpenter’s phone, and thus the location of Carpenter was “within a half-mile to two miles of the location of each of the robberies around the time the robberies happened.”[1] Carpenter was convicted. He appealed, reasserting his argument that the Fourth Amendment requires a governmental entity to obtain a search warrant based on probable cause before requiring a wireless service provider to disclose historical cell site location information.

On appeal, a divided three judge panel of the U.S. Court of Appeals for the Sixth Circuit affirmed the lower court ruling. At the outset of the opinion, the court deemed Carpenter’s historical cell site location information to be business records “created and maintained” by Carpenter’s wireless carrier MetroPCS. These types of business records, the court explained, are used by wireless service providers to track subscriber phones across different cell site sectors to connect and maintain calls, as well as find weak spots in their network and determine whether roaming charges apply. Cell site location information facilitates personal communications, but is not part of the content of those communications. With respect to the Fourth Amendment, the majority opinion distinguished the content of communications from cell site data, by explaining that “[c]ontent, per this distinction, is protected under the Fourth Amendment, but routing information is not.”[2] Consequently, the majority opinion found the government’s collection of Carpenter’s historical cell site location information was not a search under the Fourth Amendment.[3]

One of the three judges agreed with only the judgement in the majority opinion, and filed a concurring opinion to explain that the sheer quantity of sensitive information procured without a warrant in the case raises Fourth Amendment concerns of the type the Supreme Court acknowledged in United States v. Jones.

Subsequent blog posts will examine all of the other issues in Carpenter v. U.S., including what the Supreme Court said in Jones.

[1] U.S. v. Carpenter, 819 F.3d 880, 885 (6th Cir. 2016).

[2] Carpenter at 883-884.

[3] Carpenter at 890.