Schneckloth v. Bustamonte

During a routine traffic stop with no probable cause, an officer asked to search a car, and the driver's brother consented; the search turned up stolen checks later linked to passenger Robert Bustamonte (defendant), who was convicted of theft after the trial court admitted the evidence over his objection. The state appellate court affirmed, but the federal appellate court, on habeas review, held the prosecution had to prove the person who consented actually knew he had the right to refuse, reversing the district court's denial of habeas relief; the Supreme Court granted certiorari.