Carpenter v. United States

The Government conducts a Fourth Amendment search when it accesses cell phone records that include cell-site location information.

After receiving information regarding a series of robberies, the Government obtained orders pursuant to Section 2703(d) of the Stored Communications Act to acquire Petitioner’s cell-site location information (CSLI). Through CSLI, a map was produced that placed Petitioner near the location of the robberies at the time of they occurred. Petitioner moved to suppress the CSLI evidence, arguing that the Government needed a warrant supported by probable cause. The motion was denied, and Petitioner was convicted of six counts of robbery and sentenced to more than 100 years in prison.  The Sixth Circuit affirmed, holding that Petitioner lacked a reasonable expectation of privacy in CSLI because he voluntarily shared that information with wireless carriers. On appeal, the Supreme Court reversed, holding that obtaining CSLI is a search subject to Fourth Amendment protections. The Supreme Court reasoned that although the information is held by a third party, it does not negate Petitioner’s reasonable expectation of privacy in the record of his physical movements over time. Furthermore, the Supreme Court found that a 2703(d) order is not a permissible mechanism for obtaining CSLI because it does not require a finding of probable cause. Therefore, the Government was required to obtain a warrant supported by probable cause to introduce CSLI evidence at trial. REVERSED AND REMANDED.