412 U.S. 218 (1973)
On the night of January 7, 1969, at approximately 2:40 a.m. in Sunnyvale, California, Police Officer James Rand stopped an automobile because one headlight and its license plate light were burned out.1 Six men occupied the vehicle, with Joe Gonzales driving, Joe Alcala and respondent Robert Bustamonte in the front seat, and three other men in the rear.2
Gonzales could not produce a driver's license.3 Only Alcala produced identification while explaining that the car belonged to his brother.4 After the six occupants stepped out of the car at the officer's request and after two additional policemen arrived, Officer Rand asked Alcala if he could search the car. Alcala replied, "Sure, go ahead."5
Prior to the search no one was threatened with arrest, and according to Officer Rand's uncontradicted testimony it "was all very congenial at this time."6
Alcala actually helped in the search by opening the trunk and glove compartment with the keys.7 Wadded up under the left rear seat, the police officers found three checks that had previously been stolen from a car wash.8
The trial judge denied Bustamonte's motion to suppress the checks, which were introduced in evidence at his trial on a charge of possessing a check with intent to defraud.9 Bustamonte was convicted, and the California Court of Appeal for the First Appellate District affirmed the conviction.10 The California Supreme Court denied review.11 Bustamonte then sought a writ of habeas corpus in the United States District Court for the Northern District of California, which denied the petition.12
The Ninth Circuit reasoned that consent is a waiver of Fourth and Fourteenth Amendment rights.13 It held that the State must demonstrate not only that consent was uncoerced but also that it was given with an understanding that it could be freely and effectively withheld.14 The Supreme Court granted certiorari to determine whether the Fourth and Fourteenth Amendments require the showing thought necessary by the Court of Appeals.15
Whether the Fourth and Fourteenth Amendments require that the prosecution prove a person knew he had a right to refuse consent before a consent to search can be found voluntary?16
The Fourth and Fourteenth Amendments require that a consent to a search be voluntary, determined from the totality of all the circumstances.17 Knowledge of the right to refuse consent is one factor to be taken into account, but the government need not establish such knowledge as a prerequisite to establishing a voluntary consent.18
No. The Fourth and Fourteenth Amendments do not require the prosecution to prove that a person knew he had a right to refuse consent before a consent to search can be found voluntary.1920 Voluntariness is a question of fact determined from the totality of all the circumstances, and while knowledge of the right to refuse is one factor, it is not the sine qua non of an effective consent.21
Applying these principles to the facts of this case, the consent given by Alcala was voluntary.22 The stop occurred for a minor traffic violation at 2:40 a.m., the atmosphere was congenial with no threats of arrest, no guns were drawn, no force was used, and Alcala not only said "Sure, go ahead" but actively helped by opening the trunk and glove compartment.23 There is no evidence of coercion, express or implied, and the driver and passengers were not under arrest.24 The Ninth Circuit's requirement that the State affirmatively prove knowledge of the right to refuse therefore imposed an erroneous and impractical burden not supported by precedent or the traditional definition of voluntariness.25
The consent to the search was voluntary under the totality of the circumstances, the judgment of the Court of Appeals is reversed, and the case is remanded for further proceedings consistent with this holding.26
Related opinions on this issue
Justice Blackmun concurred in the opinion of the Court and added that the totality of the circumstances clearly showed the consent was voluntary.27 The driver of the car was not under arrest. He had been asked to step out of the car only for the purpose of issuing a citation.
The patrolmen did not use any force or threat of force. They simply asked if they could look in the car. The driver said that they could.28
Joined by The Chief Justice And Justice Rehnquist
Justice Powell concurred in the opinion of the Court.29 He agreed that voluntariness must be determined from the totality of all the circumstances.30 He also agreed that knowledge of the right to refuse consent is not a prerequisite to a finding of voluntariness.31
In this case the driver of the car was not in custody. He had not been arrested. The patrolmen had not drawn their guns. They had not used any force. They had simply asked if they could look in the car. The driver had said that they could. The consent was voluntary.32
Joined by Justice Marshall
Justice Brennan dissented, joined by Justice Marshall.33 He maintained that a consent to a search cannot be voluntary unless the person knows he has a right to refuse.34 The Fourth Amendment protects against unreasonable searches, and a consent search is valid only if voluntary.35
In his view a consent cannot be voluntary unless the person knows he can refuse.36 Here the driver of the car was not told that he had a right to refuse the request to search the car. He was simply asked if the patrolmen could look in the car. He said, "Okay." In his view this consent was not voluntary because the driver did not know that he had a right to refuse. He would affirm the judgment of the Court of Appeals.37
Justice Douglas dissented for the reasons stated in his dissenting opinion in Bumper v. North Carolina.38 He viewed the consent as not voluntary because the driver of the car was in a coercive situation. He had been stopped by the police.
He was without a driver's license. He was asked if the police could search his car. He was not told that he had a right to refuse. Under these circumstances the consent was not voluntary.39 He would affirm the judgment of the Court of Appeals.