The U.S. Border Patrol's Constitutional Erosion in the "100-Mile Zone"

01 Apr 2020

Supreme Court jurisprudence has established that some established constitutional provisions do not apply at the U.S. border, and protections against governmental privacy incursions are significantly reduced. As such, U.S. Customs and Border Protection (CBP) and the U.S. Border Patrol as an arm of CBP have more authority to search, seize, and detain individuals and property at border crossings than law enforcement agencies would have in other contexts. Justified by reference to the national interest in monitoring and controlling entrants to the country, the doctrine is known as the “border search exception.”
However, Border Patrol does not restrict its operations to the U.S. border. Originating in a decades-old federal statute, CBP has the authority to conduct stops and searches within a “reasonable distance” of a border, defined by regulation as 100 miles. This “100-mile zone” has been used for permanent and temporary internal checkpoints and roving stops. The extent to which the agency’s assumed expansive authority within this zone squares with constitutional principles is open to question. This Article will analyze how Fourth Amendment principles should apply to CBP authority inside national borders, including its authority to stop, question, search, and detain individuals. It will analyze the legal problems and risks attendant to an expansion of Border Patrol authority into an area encompassing the residence of about two-thirds of the U.S. population, suggesting an alternative approach that provides both clearer guidelines and more robust protections for civil liberties. Ultimately, Border Patrol activity that occurs beyond the nation’s border should be bound by ordinary constitutional restrictions applicable to all other law enforcement.