delivered the opinion of the Court.

The petitioner was convicted of grand larceny in the United States District Court for the District of Columbia and sentenced to serve sixteen months to four years in prison. Pre-trial confessions of guilt without which peti*411tioner could not have been convicted1 were admitted in evidence against his objection that they had been illegally obtained. The confessions had been made during a 30-hour period while petitioner was held a prisoner after the police had arrested him on suspicion and without a warrant.

Petitioner’s objection to the admissibility of the confessions rested on Rule 5 (a) of the Federal Rules of Criminal Procedure and our holding in McNabb v. United States, 318 U. S. 332. Rule 5 (a) provides that “An officer making an arrest . . . shall take the arrested person without unnecessary delay before the nearest available” committing magistrate and when the arrested person appears before the magistrate “a complaint shall be filed forthwith.” Petitioner contended that the officers had violated this rule in detaining him as they did without taking him before a committing magistrate. In the Mc-Nabb case we held that confessions had been improperly admitted where they were the plain result of holding and interrogating persons without carrying them “forthwith” before a committing magistrate as the law commands.

In this case the District Court thought that the McNabb ruling did not apply because the detention of petitioner “was not unreasonable under the circumstances as a matter of law.” Consequently, that court held the confessions admissible. On appeal to the United States Court of Appeals for the District of Columbia, the United States Attorney and his assistants detailed the circumstances of petitioner’s arrest and detention and *412confessed error. They concluded from these detailed circumstances that the “delay” in carrying petitioner before a committing magistrate “was unreasonable and the purpose of it, as stated by the officers themselves, was only to furnish an opportunity for further interrogation.” Under these circumstances, the district attorney thought that the McNabb rule made the confessions inadmissible without regard to whether they were “voluntary” in the legal sense. The delay in taking petitioner before a judicial officer was thought, in the words of the district attorney, to have been “for purposes inimical to the letter and spirit of the rule requiring prompt arraignment.”

The Court of Appeals rejected this confession of error, one judge dissenting. 83 U. S. App. D. C. 207, 168 F. 2d 167. It read the McNabb case as explained in United States v. Mitchell, 322 U. S. 65, as holding that “A confession voluntarily given is admissible in evidence” while conversely “a confession involuntarily made is inadmissible.” 83 U. S. App. D. C. 207, 168 F. 2d 167. That court thought the McNabb case did no more than extend the meaning of “involuntary” confessions to proscribe confessions induced by psychological coercion as well as those brought about by physical brutality. Finding no psychological coercion in the facts of this case, the court concluded that the confessions were not the “fruit of the illegal detention.” The court also laid stress on the fact that the petitioner’s detention unlike McNabb’s, “was not aggravated by continuous questioning for many hours by numerous officers.”

We hold that this case falls squarely within the McNabb ruling and is not taken out of it by what was decided in the Mitchell case. In the McNabb case we held that the plain purpose of the requirement that prisoners should promptly be taken before committing magistrates was to check resort by officers to “secret interrogation of persons accused of crime.” We then *413pointed out the circumstances under which petitioners were interrogated and confessed. This was done to show that the record left no doubt that the McNabbs were not promptly taken before a judicial officer as the law required, but instead were held for secret questioning, and “that the questioning of the petitioners took place while they were in the custody of the arresting officers and before any order of commitment was made.” The Me-Nabb confessions were thus held inadmissible because the McNabbs were questioned while held in “plain disregard of the duty enjoined by Congress upon federal law officers” promptly to take them before a judicial officer. In the McNabb case there were confessions “induced by illegal detention,” United States v. Mitchell, supra at 70, a fact which this Court found did not exist in the Mitchell case.

In the Mitchell case although the defendant was illegally held eight days, the court accepted the record as showing that Mitchell promptly and spontaneously admitted his guilt within a few minutes after his arrival at the police station. Mitchell’s confessions therefore were found to have been made before any illegal detention had occurred. This Court then stated in the Mitchell opinion that “the illegality of Mitchell’s detention does not retroactively change the circumstances under which he made the disclosures.” Thus the holding in the Mitchell case was only that Mitchell’s subsequent illegal detention did not render inadmissible his prior confessions. They were held not to involve “use by the Government of the fruits of wrongdoing by its officers.” The Mitchell case at p. 68, however, reaffirms the McNabb rule that a confession is inadmissible if made during illegal detention due to failure promptly to carry a prisoner before a committing magistrate, whether or not the “confession is the result of torture, physical or psychological . . . .”

*414In this case we are left in no doubt as to why this petitioner was not brought promptly before a committing magistrate. The arresting officer himself stated that petitioner was not carried before a magistrate on Friday or Saturday morning after his arrest on Friday at 2 a. m., because the officer thought there was not “a sufficient case” for the court to hold him, adding that even “if the Police Court did hold him we would lose custody of him and I no longer would be able to question him.” Thus the arresting officer in effect conceded that the confessions here were “the fruits of wrongdoing” by the police officers. He conceded more: He admitted that petitioner was illegally detained for at least thirty hours for the very purpose of securing these challenged confessions. He thereby refutes any possibility of an argument that after arrest he was carried before a magistrate “without unnecessary delay.”

The argument was made to the trial court that this method of arresting, holding, and questioning people on mere suspicion was in accordance with the “usual police procedure of questioning a suspect . . . .” However usual this practice, it is in violation of law, and confessions thus obtained are inadmissible under the McNabb rule. We adhere to that rule.2

Reversed.

dissenting.

When not inconsistent with a statute, or the Constitution, there is no doubt of the power of this Court to institute, on its own initiative, reforms in the federal practice *415as to the admissibility of evidence in criminal trials in federal courts.1 This power of reform, which existed at the time, March 1, 1943, McNabb v. United States, 318 U. S. 332, was decided, is not, I believe, restricted by the language of Rule 26 of the Federal Rules of Criminal Procedure, effective March 21, 1946. Federal Rule of Criminal Procedure No. 59; 91 Cong. Rec. 12,545. The admissibility of evidence, like the competency of witnesses, is “governed by common law principles as interpreted and applied by the federal courts in the light of reason and experience.” Wolfle v. United States, 291 U. S. 7, 12.2 While judicial innovations explicitly expanding or contracting admissibility of evidence are rare, *416there have been sufficient occasions to establish by precedent and legislative acceptance that the power exists. McNabb v. United States, supra, 341.3

Such power should be used to change the established rules of evidence, however, only when “fundamentally altered conditions/’ note 2, supra, call for such a change in the interests of justice. Otherwise the bad results from a change of well-established rules are quite likely to outweigh the good. The lack of any necessity for changing the rules of evidence to protect an accused led me to dissent in the McNabb case, a murder case where an assumed failure to commit the prisoners apparently was relied upon as a partial basis for denying admissibility to certain confessions.

My objection to this Court’s action of today in what seems to me an extension of the scope of nonadmissibility of confessions in the federal courts is not to its power so to act but to the advisability of such an additional step. Unless Congress or a majority of this Court modifies the McNabb rule, I feel bound to follow my understanding of its meaning in similar cases that may arise, but that duty does not impose upon me the obligation to accept this ruling as to Upshaw which seems to me to compound certain unfortunate results of the McNabb decision by extending it to circumstances beyond the scope of the McNabb ruling. This attitude leads me (I) to analyze the McNabb case and its offspring, (II) to point out why I think the present decision goes beyond the holding in McNabb and (III) to point out why McNabb should not be extended.

*417The judicial approach to the problem, of course, must be in a spirit of cooperation with the police officials in the administration of justice. They are directly charged with the responsibility for the maintenance of law and order and are under the same obligation as the judicial arm to discharge their duties in a manner consistent with the Constitution and statutes. The prevention and punishment of crime is a difficult and dangerous task, for the most part performed by security and prosecuting personnel in a spirit of public service to the community. Only by the maintenance of order may the rights of the criminal and the law-abiding elements of the population be protected. As has been pointed out by this Court in the McNabb and Mitchell cases, United States v. Mitchell, 322 U. S. 65, there is no constitutional problem involved in deciding whether a voluntary confession given by a prisoner prior to commitment by a magistrate should be admitted in evidence. A prisoner’s constitutional rights against self-incrimination or to due process are protected by the rule that no involuntary confession may be admitted. McNabb v. United States, supra, pp. 339-40 and cases cited; Haley v. Ohio, 332 U. S. 596; Malinski v. New York, 324 U. S. 401; Ashcraft v. Tennessee, 322 U. S. 143.

I.

Our first inquiry, then, is as to the legal doctrine behind the McNabb decision.

A. Were the McNabb confessions barred as a punishment or penalty against the police officers because they were thought to have disobeyed the command of a statute?

B. Were they barred because unlawful imprisonment is so apt to be followed by an involuntary confession as to justify the exclusion of all confessions received before judicial commitment after a prisoner is kept in custody *418more than a reasonable time without being taken before a committing magistrate?

C. Were they barred because the particular circumstances under which the confessions were made were so likely to produce involuntary confessions as to justify exclusion?

A. As the McNabb decision was a sudden departure from the former federal rule as to the admissibility of confessions4 initiated by the Court, without the benefit of brief or argument and without knowledge of the actual facts as to commitment,5 it can hardly be expected that *419it could have the desirable explicitness of a trite rule of evidence. Consequently confusion immediately arose as to its meaning. The dissent interpreted the opinion as a direction to exclude the confessions “because in addition to questioning the petitioners, the arresting officers failed promptly to take them before a committing magistrate.” It concluded: “The officers of the Alcohol Tax Unit should not be disciplined by overturning this conviction.” McNabb v. United, States, supra, p. 349. Some courts thought that any confession obtained before commitment was inadmissible. United States v. Hoffman, 137 F. 2d 416, 421; Mitchell v. United States, 78 U. S. App. D. C. 171, 172, 138 F. 2d 426, 427. Others have understood the case to determine admissibility of confessions by a coercion test.6 Varying impressions as to the rule that the McNabb case announced appear in the cases.7 The Spe*420cial Committee on the Bill of Rights of the American Bar Association under date of May 15, 1944, advised Subcommittee No. 2 of the Committee on the Judiciary of the House of Representatives that before the McNabb case “there was no effective penalty in operation. . . .

“Then came the McNabb case which did impose a drastic penalty. The seven majority Justices held that unlawful detention shut out the confession. The decision made the speedy production statutes really mean something. The police were no longer left free to enforce the law by disobeying the law.” P. v.

Five members of the Special Committee, apparently under the Chairmanship of Professor Zechariah Chafee, Jr., also submitted a Memorandum which said, “The McNabb rule excluding confessions obtained during unlawful detention is an effective penalty for violation of the Acts of Congress.” P. 19. It added:

“Congress should be very reluctant to take away the only effective penalty now existing for violation of the fundamental right to have the continuance of custody determined by a magistrate and not by the uncontrolled will of the police, however able and devoted they may be.” P. 25.8

Notwithstanding that some did gain the impression from the McNabb case that it was intended as a discipline of police officers for the violation of the commitment stat*421utes, a reading of McNabb as later explained by United States v. Mitchell, supra, negatives such a conclusion.

It is true that there are phrases in the McNabb opinion that condemn the assumed failure to take the accused promptly before a magistrate.9 Further Benjamin’s confession was barred even though it was given within “five or six hours” of questioning, and without the slightest suggestion of force, after his voluntary surrender because he had heard the officers were looking for him. Perhaps the strongest indication that the McNabb decision may have been intended as a penalty for police misconduct occurs in another case decided the same day as McNabb, Anderson v. United States, 318 U. S. 350. There a man was arrested Sunday night and confessed after two hours’ questioning on Monday morning. Nevertheless his confession was held inadmissible under authority of McNabb. P. 355.

However, United States v. Mitchell, supra, made it clear that the purpose of McNabb was not to enforce a penalty for police misconduct.10 In the Mitchell case a suspect was arrested and taken to the police station. He confessed within a few minutes of his arrival. He was illegally detained for eight days before being taken before a committing magistrate. “The police explanation of this illegality is that Mitchell was kept in such *422custody without protest through a desire to aid the police in clearing up thirty housebreakings . . . This Court then pronounced this statement as to the exclusion of the confessions as evidence, “These, we have seen, were not elicited through illegality. Their admission, therefore, would not be use by the Government of the fruits of wrongdoing by its officers. Being relevant, they could be excluded only as a punitive measure against unrelated wrongdoing by the police. Our duty in shaping rules of evidence relates to the propriety of admitting evidence. This power is not to be used as an indirect mode of disciplining misconduct.” Pp. 70-71. The Mitchell explanation of McNabb seems correct. It is not the function of courts to provide penalties and sanctions for acts forbidden by statutes where neither statutes nor the common law nor equity procedure have established them.

For the above reasons, I reach the conclusion that the McNabb case was not intended as a penalty or sanction for violation of the commitment statute.

B. The Court bases its decision of today on the theory that “a confession is inadmissible if made during illegal detention due to failure promptly to carry a prisoner before a committing magistrate, whether or not the ‘confession is the result of torture, physical or psychological ....’” The Court holds that this was the McNabb rule and adheres to it. I do not think this was the McNabb rule and I do think the rule as now stated is an unwarranted extension of the rule taught by the McNabb case. My reasons follow.

There is no legal theory expressed in McNabb that supports the idea that every confession after unnecessary delay and before commitment is inadmissible. There are a few isolated sentences that do lend credence to such an explanation of the legal theory behind the case, but when read in context, I think it is clear that they do *423not expound such a rule.11 The physical conditions of the restraint are emphasized, pp. 335-38 and 344-45. Attention is called to the examination, when stripped, of one man. P. 337.12 The Mitchell case, supra, p. 67, removes all my doubts as to the true McNabb rule. It says: “Inexcusable detention for the purpose of illegally extracting evidence from an accused, and the successful extraction of such inculpatory statements by continuous questioning for many hours under psychological pressure, were the decisive features in the McNabb case which led us to rule that a conviction on such evidence could not stand.”13

*424During detention in violation of the federal commitment statute is the likelihood that police officials will use coercion for the extraction of an involuntary confession so strong as to justify the exclusion by this Court of all confessions to the police obtained after their failure to conform to the requirement of prompt production of the accused before a magistrate? I think not. It must be admitted that a prompt hearing gives an accused an opportunity to obtain a lawyer;14 to secure from him advice as to maintaining an absolute silence to all questions, no matter how apparently innocuous; to gain complete freedom from police interrogation in all bailable offenses; 15 and that these privileges are more valuable to the illiterate and inexperienced than to the educated and well-briefed accused. Proper protection of the ignorant is of course desirable, but the rule now announced forces exclusion of all confessions given during illegal restraint. It will shift the inquiry to the legality of the arrest and restraint, rather than to whether the confession was voluntary. Such exclusion becomes automatic on proof of detention in violation of the commitment statute, followed by a confession to police officials before commitment. It is now made analogous to the exclusion of evidence obtained in violation of the Bill of Rights through unreasonable search and seizure or through compulsion or by denial of due process. I do not think this is the doctrine of the McNabb case or that it should now be made an explicit rule of federal law.

The rule as to the inadmissibility of evidence in federal courts obtained in violation of the Bill of Rights, Fourth and Fifth Amendments is, it seems to me, inapplicable *425as an analogy to a situation such as existed in the McNabb case and here.16 By assumption of this Court, in the McNabb case the McNabb confessions were obtained without “disregard of liberties deemed fundamental by the Constitution,” McNabb v. United States, supra, 339, i. e., without violation of the Bill of Rights. I take it the same assumption applies as to Upshaw. Under this assumption, the McNabb confessions would have been admissible if the Court had not believed there was a failure to follow the statute on commitments. Confessions, of course, are also inadmissible when coerced in violation of constitutional due process under the Fourteenth Amendment. Malinski v. New York, 324 U. S. 401, 404; Haley v. Ohio, 332 U. S. 596. When other evidence is the direct result of an unconstitutional act such as a violation of the Fourth Amendment, this Court has said, in federal cases, that to permit its use would impair the protection of this major guaranty of a free *426country.17 When, as in the McNabb case, there are confessions after failure to observe statutory directions not shown to have coerced the confessions the rule as to evidence extracted in defiance of the Constitution does not apply.18

*427This Court by decision has excluded evidence obtained by unreasonable search and seizure under the Fourth Amendment or by coercion to a degree that violates the Fifth or the Fourteenth Amendments because the admission of such evidence would imperil the efficacy of those constitutional rights. If confessions obtained during unlawful detention are not excluded by the fact of unlawful detention alone, the constitutionally guaranteed rights of the accused are nevertheless protected by the rule that no involuntary confession is admissible. It is therefore unnecessary for constitutional reasons to extend this protection to evidence obtained through violation of a statute or a rule of criminal procedure by those to whom the confession is made. In criminal trials, the method of obtaining evidence has never been a reason for barring its use except where constitutional rights were violated.19 The prohibition of wiretapping in § 605 of the Federal Communications Act is not the basis for the exclusion in prosecutions of evidence so obtained. The exclusion of such evidence is based on an explicit direction of the section that information so obtained should not be divulged.20 Congress could, of course, pass such a statute to prohibit the use of a confession as evidence, if obtained during an unlawful detention. The rule of the Olmstead *428case, 277 U. S. 438, 466, derived from the common law that the admissibility of evidence is not affected by conduct of investigators where there is no violation of a constitutional guaranty, stands unimpaired.

If this judicial rule of exclusion of all confessions secured after illegal detention is adhered to, it must mean that this Court thinks illegal detention is so likely to result in “third degree” that it should be outlawed per se. There is a reference to “third degree” in McNabb, p. 344, but, as indicated above, p. 425, no reliance upon the detention as coercive in the due process sense.21 If illegal detention, per se, is believed sufficiently likely to produce a coerced confession as to justify exclusion of such confessions as evidence, it does not require this extension of the McNabb rule to make such evidence inadmissible. A court never knows whether a confession is or is not voluntary. It bars confessions on uncontroverted proof of facts which as a matter of law are deemed so coercive as to be likely to produce an involuntary confession. Chambers v. Florida, 309 U. S. 227, 238-39; Malinski v. New York, 324 U. S. 401, 404. If illegal detention alone were deemed that coercive, the confessions would be barred as a matter of due process in both state and federal courts.22 So here if illegal detention alone is the decisive *429factor, the rule of exclusion surely will apply to both state and federal trials as violative of the Due Process Clause. But the McNabb rule does not apply to trials in state courts.23 It is because illegal detention was not thought to be per se coercive that it was necessary to create the McNabb rule of exclusion.

For the foregoing reasons, I conclude that detention alone, even for the purpose of obtaining information, should not be sufficient to justify the exclusion of a confession to police officers obtained after unnecessary delay and before commitment.

C. This brings me to a statement of the true rule of the McNabb case, as I understand it. This rule is that purposeful, unlawful detention illegally to extract evidence and the successful extraction of confessions under psychological pressure, other than mere detention for limited periods, makes confessions so obtained inadmissible. This statement is a paraphrase of the Mitchell interpretation referred to in the preceding subdivision. It means that pressure short of coercion but beyond mere detention makes confessions inadmissible. Obviously there is a wide range of discretion as to how much psychological pressure is necessary. If any material amount is sufficient, the rule differs little from one denying admissibility if obtained during illegal restraint. If almost coercion is required, the rule will differ little from that excluding an involuntary confession. Under this interpretation of McNabb, I suppose, as in coerced confessions, it should be left to a jury to decide whether there was enough evidence of pressure where the admitted facts do not show improper pressure as a matter of law.

*430II.

The Court now says that illegal detention alone is sufficient to bar from evidence a confession to the police during that unlawful detention. As I think this is an improper extension of the McNabb rule, I proceed to state the application of the McNabb rule, as I understand it, to Upshaw’s situation. Perhaps Upshaw’s arrest without a warrant was also without reasonable cause on the part of the arresting officer to believe he had committed a felony. This unlawful arrest is not relied upon in the opinion. So far as the admissibility of the confession is concerned, it makes no difference that it may have been obtained as the result of an illegal arrest or an unlawful detention. I think there was less psychological pressure upon Upshaw than there was upon the McNabbs. That precedent, therefore, if the true McNabb rule is properly stated in Part I, subdivision C, above, does not require me to declare Upshaw’s confession inadmissible. In the Mc-Nabbs’ case, the facts of their illegal detention that caused this Court’s action appear from the opinion as set out below.24 As for Upshaw the facts are detailed in the foot*433note.25 The time between confession and commitment is not significant. United States v. Mitchell, supra. The indications of pressure on the McNabbs that lead me to *434conclude that the Court should hold Upshaw’s confession admissible under my understanding of the McNabb rule before this present holding are the lack of experience of the McNabbs, the “breaking” of Benjamin by confrontation of charges of his guilt by his relatives and confederates, the greater number of officers questioning them, and the longer time the McNabb group was interrogated.26

HH 1 — 1 I — I

I do not agree that .we should now extend the McNabb rule by saying that every confession obtained by police after unnecessary delay in arraignment for commitment and before magisterial commitment must be barred from the trial. Those most concerned with a proper administration of the criminal law are against any extension.

(1) The departure of the McNabb and Anderson cases from well-established methods for protection against coercion has been condemned by the House of Representatives and not acted upon by the Senate.27

(2) Officers charged with enforcement of the criminal law have objected for the reason that fear of the application of its drastic penalties deterred officers from questioning during reasonable delays in commitment.28

(3) State courts under similar laws and conditions have refused to follow the McNabb example.29

*435(4) Law Review comment generally condemns the rule.30

In the Federal Rules of Criminal Procedure, Preliminary Draft, submitted May 3, 1943, to this Court, there was included a § 5 (b) which purported to codify the McNabb rule.31 In response to widespread opposition to such a codification,32 this section of Rule 5 was omitted from the final draft. These rules were drawn by a representative committee of the bench and bar with wide participation beyond the membership by interested parties from both groups. They were transmitted on December 26, 1944, by this Court to the Attorney General to be reported to Congress, more than a year after the McNabb case and after the hearings on the House bill to nullify the McNabb rule. Neither this Court nor the Congress restored the rejected proposal.

Instead of an extension of the McNabb rule, I feel that it should be left, as I think it originally was, a rule that barred a confession extracted under psychological pressure of the degree used in the McNabb case.

Such condemnation of even the restricted McNabb rule by those immediately responsible for the enactment and *436administration of our criminal laws should make this Court, so far removed from the actualities of crime prevention, hesitate long before pushing farther by judicial legislation its conception of the proprieties in criminal investigation. It takes this step in the belief that thereby it strengthens criminal administration by protecting, a prisoner. A prisoner should have protection but it is well to remember that law and order is an essential prerequisite to the protection of the security of all. Today’s decision puts another weapon in the hand of the criminal world. Apparently the Court intends to make the rule of commitment “without unnecessary delay” 33 an iron rule without flexibility to meet the emergencies of conspiracies, search for confederates, or examining into the ramifications of criminality. The Court does this by failing to distinguish between necessary and unnecessary delay in commitment. It uses words like “forthwith” and “promptly” and thus destroys the leeway given by the Rule to police investigations. All, I think, without any need for such action since every coerced confession has been inadmissible for generations. The position stated in this dissent does not envisage a surrender to evils in the handling of criminals. If there is a prevalent abuse of the right to question prisoners, the sounder remedy lies in police discipline, in statutory punishment of offending officials, in vigorous judicial protection against unconstitutional pressures for confessions, and in legisla*437tive enactments for inquiries into circumstances surrounding crimes by methods that protect both the public and suspects — for example, an inquiry before a magistrate with sealed evidence.

I would affirm this conviction in reliance upon the verdict of the properly instructed jury that this was a voluntary confession.