In Brown v. Texas, 443 U.S. 47 (1979), El Paso Police Officers detained the defendant and ultimately arrested him pursuant to a Texas statute making it a crime to not identify oneself when requested by law enforcement. (Id. at pp. 48-49.) The court stated that police cannot stop and demand identification absent a specific basis for believing the subject is engaged in criminal activity. (Id. at p. 52.) The United States Supreme Court set forth a balancing test for determining the validity of a traffic stop based on less than probable cause or "articulable and reasonable suspicion" of criminal activity. The test involves weighing: (1) the gravity of the public concerns served by the seizure; (2) the degree to which the seizure advances the public interest; (3) the severity of the interference with individual liberty. See 443 U.S. at 50-51. If, on balance, these factors weigh in favor of the public interest, the checkpoint is reasonable and therefore constitutional. See, e.g., Illinois v. Lidster, 540 U.S. 419 (2004). Noting the central constitutional concern that "an individual's reasonable expectation of privacy is not subject to arbitrary invasions solely at the unfettered discretion of officers in the field," the Court said, "the Fourth Amendment requires that a seizure must be based on specific, objective facts indicating that society's legitimate interests require the seizure of the particular individual, or that the seizure must be carried out pursuant to a plan embodying explicit, neutral limitations on the conduct of individual officers." Id. at 51.