"The principal protection of Fourth Amendment rights at checkpoints lies in appropriate limitations on the scope of the stop. See Terry v. Ohio, 392 U.S.; United States v. Brignoni-Ponce, 422 U.S... And our holding today is limited to the type of stops described in this opinion. "[A]ny further detention . . . must be based on consent or probable cause." United States v. Brignoni-Ponce."
- Martinez-Fuerte, Supreme Court of the United States, 1976
"We have already noted that the permissible duration of the stop is limited to the time reasonably necessary to complete a brief investigation of the matter within the scope of the stop. The scope of an immigration stop is limited to...determining the citizenship status of persons passing through the checkpoint."
"In United States v. Machuca-Barerra, we addressed those limitations in detail and noted that 'The scope of an immigration stop is limited to...determining the citizenship status of persons passing through the checkpoint...' It bears repeating that the permissible duration of an immigration stop is the time reasonably necessary to determine the citizenship status of the persons stopped."
- Portillo-Aquirre, Fifth Circuit Court of Appeals, 2002
"We have not discovered nor been shown any authority supporting Rynearson’s claim that the constitutional rights he chose to stand on [the right to be detained only as long as is reasonably necessary to briefly investigate citizenship status] were clearly established."