An officer on patrol at 2:30 in the morning observed an automobile with a broken headlight. He stopped the car, and the driver was unable to produce a driver's license. There were five other passengers, and only one could produce a license. The officer asked that person (who said that the car was his brother's) if he could search the car. Prior to the search, no one was threatened with arrest. The person allowed him to search, and the officer found three stolen checks. Bustamonte (D) was convicted after these checks were admitted into evidence at his trial. The Court of Appeal affirmed his conviction. D sought a writ of habeas corpus in a federal district court. He was denied, but the Court of Appeals set aside the district court's order. The appellate court reasoned that a consent was a waiver of a person's Fourth and Fourteenth Amendment rights and that the State was under an obligation to demonstrate, not only that the consent had been uncoerced, but that it had been given with an understanding that it could be freely and effectively withheld. Schneckloth (P) appealed.