Carpenter v. United States


Does the warrantless search and seizure of cell phone records, which include the location and movements of cell phone users, violate the Fourth Amendment?1

  1. We talked about this case in Episode 43. More information about the case can be found here

5-4 U.S.

7-2 Carpenter

9-0 Carpenter

Case Outcome

5-4 Carpenter


During the investigation of a bank robbery, the FBI requested the cellphone records of one of the alleged robbers without a warrant. The records that the Government got from the cell providers include “date and time of calls, and the approximate location where calls began and ended based on their connections to cell towers—“cell site” information.” The FBI requested this information for 127 days of the defendant’s activity.

The defendant challenged this under the Fourth Amendment; The circuit court upheld his conviction under the third-party doctrine.

The issue in this case is how far does the third-party doctrine stretch? There are two relevant cases:

  • United States v. Miller: Holding that bank records seized by the government were not a Fourth Amendment violation because you can’t have an expectation of privacy in infromation you disclosed to a third party.
  • Smith v. Maryland: the use of a pen register to tap the phones of a defendant to learn who he was calling is not a search.

With the use of cell phone tracking, it was argued that the government could learn your location as precise as a 20

Justice Gorsuch questioned the parties on a property based view of the Fourth Amendment. If the defendant owned the location and other information he gave to the third party, while it may not be a search of his person, wouldn’t it be a search of his papers and effects under the Fourth Amendment?

The Government argues that the defendant doesn’t have an ownership interest in the data. The Government says this would be a different case if it forced the cell phone providers to keep such data. But the cell phone providers keep the data in their normal course of business for their own business purposes. So, like any other subpoena, the Government is just requesting information of a third party.

The tough part for the Defendant is how does he differentiate bank records, which the court has said is not a search with cell phone records in this case?

Add your prediction