Carter v. United States of America

On December 9, 2025, Thomas Carter was convicted in the U.S. District Court for the Southern District of New York on multiple counts, including conspiracy to distribute cocaine, money laundering, and operating a continuing criminal enterprise. The investigation, led by the DEA, utilized a cell-site simulator without a warrant to track Carter’s movements within 100 miles of the U.S.-Mexico border, gathering key evidence that linked him to drug shipments and bulk cash transfers. Carter appealed the conviction, arguing that the warrantless deployment of the device constituted an unconstitutional search under the Fourth Amendment. The Supreme Court granted certiorari to resolve the novel question of whether the border-search exception extends to warrantless digital location tracking. In a 5-4 decision, the Court affirmed the conviction, holding that individuals have no reasonable expectation of privacy in location data obtained near the border, given the government’s compelling interest in combating transnational drug trafficking. Carter’s life sentence was upheld.

In a 5-4 ruling, the U.S. Supreme Court upheld Carter’s conviction and life sentence. The majority held that the border-search doctrine permits warrantless digital tracking near international borders, concluding that travelers and residents in that zone have a diminished expectation of privacy.

Whether the warrantless use of a cell-site simulator to track an individual’s real-time location within the border zone violates the Fourth Amendment’s prohibition against unreasonable searches, or falls within the recognized border-search exception.

The ruling sparked widespread concern among civil liberties organizations, who warned that it creates a “Constitution-free zone” for millions of Americans living or traveling near borders. The decision intensified legislative debates over the need for statutory warrants for cell-site simulators and raised broader questions about the erosion of Fourth Amendment protections in an era of advanced surveillance technology.