MR. JUSTICE WHITE delivered the opinion of the Court.
In these two cases we are called upon to decide whether a summons directing an attorney to produce documents delivered to him by his client in connection with the attorney-client relationship is enforceable over claims that the documents were constitutionally immune from summons in the hands of the client and retained that immunity in the hands of the attorney.
In each case, an Internal Revenue agent visited the taxpayer or taxpayers
In No. 74-18, the documents demanded were analyses by the accountant of the taxpayers' income and expenses which had been copied by the accountant from the taxpayers' canceled checks and deposit receipts.
In each case the summons was ordered enforced by the District Court and its order was stayed pending appeal. In No. 74-18, 500 F.2d 683 (CA3 1974), petitioners' appeal raised, in terms, only their Fifth Amendment claim, but they argued in connection with that claim that enforcement of the summons would involve a violation of the taxpayers' reasonable expectation of privacy and particularly so in light of the confidential relationship of attorney to client. The Court of Appeals for the Third Circuit after reargument en banc affirmed the enforcement order, holding that the taxpayers had never acquired a possessory interest in the documents and that the papers were not immune in the hands of the attorney. In No. 74-611, a divided panel of the Court of Appeals for the Fifth Circuit reversed the enforcement order, 499 F.2d 444 (1974). The court reasoned that by virtue of the Fifth Amendment the documents would have been privileged
All of the parties in these cases and the Court of Appeals for the Fifth Circuit have concurred in the proposition that if the Fifth Amendment would have excused a taxpayer from turning over the accountant's papers had he possessed them, the attorney to whom they are delivered for the purpose of obtaining legal advice should also be immune from subpoena. Although we agree with this proposition for the reasons set forth in Part III, infra, we are convinced that, under our decision in Couch v. United States, 409 U.S. 322 (1973), it is not the taxpayer's Fifth Amendment privilege that would excuse the attorney from production.
The relevant part of that Amendment provides:
Here, the taxpayers are compelled to do no more than was the taxpayer in Couch. The taxpayers' Fifth Amendment privilege is therefore not violated by enforcement of the summonses directed toward their attorneys. This is true whether or not the Amendment would have barred a subpoena directing the taxpayer to produce the documents while they were in his hands.
The fact that the attorneys are agents of the taxpayers does not change this result. Couch held as much, since the accountant there was also the taxpayer's agent, and in this respect reflected a longstanding view. In
Nor is this one of those situations, which Couch suggested might exist, where constructive possession is so clear or relinquishment of possession so temporary and insignificant as to leave the personal compulsion upon the taxpayer substantially intact. 409 U. S., at 333. In this respect we see no difference between the delivery to the attorneys in these cases and delivery to the accountant in the Couch case. As was true in Couch, the documents sought were obtainable without personal compulsion on the accused.
Respondents in No. 74-611 and petitioners in No. 74-18 argue, and the Court of Appeals for the Fifth Circuit apparently agreed, that if the summons was enforced, the taxpayers' Fifth Amendment privilege would be, but should not be, lost solely because they gave their documents to their lawyers in order to obtain legal advice. But this misconceives the nature of the constitutional privilege. The Amendment protects a person from being compelled to be a witness against himself. Here, the taxpayers retained any privilege they ever had not to be compelled to testify against themselves and not to be compelled themselves to produce private papers in their possession. This personal privilege was in no way decreased by the transfer. It is simply that by
The Court of Appeals for the Fifth Circuit suggested that because legally and ethically the attorney was required to respect the confidences of his client, the latter had a reasonable expectation of privacy for the records in the hands of the attorney and therefore did not forfeit his Fifth Amendment privilege with respect to the records by transferring them in order to obtain legal advice. It is true that the Court has often stated that one of the several purposes served by the constitutional privilege against compelled testimonial self-incrimination is that of protecting personal privacy. See, e. g., Murphy v. Waterfront Comm'n, 378 U.S. 52, 55 (1964); Couch v. United States, supra, at 332, 335-336; Tehan v. United States ex rel. Shott, 382 U.S. 406, 416 (1966); Davis v. United States, 328 U.S. 582, 587 (1946). But the Court has never suggested that every invasion of privacy violates the privilege. Within the limits imposed by the language of the Fifth Amendment, which we necessarily observe, the privilege truly serves privacy interests; but the Court has never on any ground, personal privacy included, applied the Fifth Amendment to prevent the otherwise proper acquisition or use of evidence which, in the Court's view, did not involve compelled testimonial self-incrimination of some sort.
Insofar as private information not obtained through compelled self-incriminating testimony is legally protected, its protection stems from other sources
Our above holding is that compelled production of documents from an attorney does not implicate whatever Fifth Amendment privilege the taxpayer might have enjoyed from being compelled to produce them himself. The taxpayers in these cases, however, have from the out-set consistently urged that they should not be forced to expose otherwise protected documents to summons simply because they have sought legal advice and turned the papers over to their attorneys. The Government appears to agree unqualifiedly. The difficulty is that the taxpayers have erroneously relied on the Fifth Amendment without urging the attorney-client privilege in so many words. They have nevertheless invoked the relevant body of law and policies that govern the attorney-client privilege. In this posture of the case, we feel obliged to inquire whether the attorney-client privilege applies to documents in the hands of an attorney which would have been privileged in the hands of the client by reason of the Fifth Amendment.
Since each taxpayer transferred possession of the documents in question from himself to his attorney in order to obtain legal assistance in the tax investigations in question, the papers, if unobtainable by summons from the client, are unobtainable by summons directed to the attorney by reason of the attorney-client privilege. We accordingly proceed to the question whether the documents could have been obtained by summons addressed to the taxpayer while the documents were in his possession. The only bar to enforcement of such summons asserted by the parties or the courts below is the Fifth Amendment's privilege against self-incrimination. On this question the Court of Appeals for the Fifth Circuit in No. 74-611 is at odds with the Court of Appeals for the Second Circuit in United States v. Beattie, 522 F.2d 267 (1975), cert. pending, Nos. 75-407, 75-700.
The proposition that the Fifth Amendment prevents compelled production of documents over objection that such production might incriminate stems from Boyd v. United States, 116 U.S. 616 (1886). Boyd involved a civil forfeiture proceeding brought by the Government against two partners for fraudulently attempting to import 35 cases of glass without paying the prescribed duty. The partnership had contracted with the Government to furnish the glass needed in the construction of a Government building. The glass specified was foreign glass, it being understood that if part or all of the glass was furnished from the partnership's existing duty-paid inventory,
Among its several pronouncements, Boyd was understood to declare that the seizure, under warrant or otherwise, of any purely evidentiary materials violated the Fourth Amendment and that the Fifth Amendment rendered these seized materials inadmissible. Gouled v. United States, 255 U.S. 298 (1921); Agnello v. United States, 269 U.S. 20 (1925); United States v. Lefkowitz, 285 U.S. 452 (1932). That rule applied to documents as well as to other evidentiary items—"[t]here is no special sanctity in papers, as distinguished from other forms of property, to render them immune from search and seizure, if only they fall within the scope of the principles of the cases in which other property may be seized . . . ." Gouled v. United States, supra, at 309. Private papers taken from the taxpayer, like other "mere evidence," could not be used against the accused over his Fourth and Fifth Amendment objections.
Several of Boyd's express or implicit declarations have not stood the test of time. The application of the Fourth Amendment to subpoenas was limited by Hale v. Henkel, 201 U.S. 43 (1906), and more recent cases. See, e. g., Oklahoma Press Pub. Co. v. Walling, 327 U.S. 186 (1946). Purely evidentiary (but "nontestimonial") materials, as well as contraband and fruits and instrumentalities of crime, may now be searched for and seized under proper circumstances, Warden v. Hayden, 387 U.S. 294 (1967).
It is also clear that the Fifth Amendment does not independently proscribe the compelled production of every sort of incriminating evidence but applies only when the accused is compelled to make a testimonial communication that is incriminating. We have, accordingly, declined to extend the protection of the privilege to the giving of blood samples, Schmerber v. California, 384 U.S. 757, 763-764 (1966);
The pronouncement in Boyd that a person may not be forced to produce his private papers has nonetheless often appeared as dictum in later opinions of this Court. See, e. g., Wilson v. United States, 221 U.S. 361, 377 (1911); Wheeler v. United States, 226 U.S. 478, 489 (1913); United States v. White, 322 U.S. 694, 698-699
A subpoena served on a taxpayer requiring him to produce an accountant's workpapers in his possession without doubt involves substantial compulsion. But it does not compel oral testimony; nor would it ordinarily compel the taxpayer to restate, repeat, or affirm the truth of the contents of the documents sought. Therefore, the Fifth Amendment would not be violated by the fact alone that the papers on their face might incriminate the taxpayer, for the privilege protects a person only against being incriminated by his own compelled testimonial communications. Schmerber v. California, supra; United States v. Wade, supra; and Gilbert v. California, supra. The accountant's workpapers are not the taxpayer's. They were not prepared by the taxpayer, and they contain no testimonial declarations by him. Furthermore, as far as this record demonstrates, the preparation of all of the papers sought in these cases was wholly voluntary, and they cannot be said to contain compelled
The act of producing evidence in response to a subpoena nevertheless has communicative aspects of its own, wholly aside from the contents of the papers produced. Compliance with the subpoena tacitly concedes the existence of the papers demanded and their possession or control by the taxpayer. It also would indicate the taxpayer's belief that the papers are those described in the subpoena. Curcio v. United States, 354 U.S. 118, 125 (1957). The elements of compulsion are clearly present, but the more difficult issues are whether the tacit averments of the taxpayer are both "testimonial" and "incriminating" for purposes of applying the Fifth Amendment. These questions perhaps do not lend themselves to categorical answers; their resolution may instead depend on the facts and circumstances of particular cases or classes thereof. In light of the records now before us, we are confident that however incriminating the
It is doubtful that implicitly admitting the existence and possession of the papers rises to the level of testimony within the protection of the Fifth Amendment. The papers belong to the accountant, were prepared by him, and are the kind usually prepared by an accountant working on the tax returns of his client. Surely the Government is in no way relying on the "truthtelling" of the taxpayer to prove the existence of or his access to the documents. 8 Wigmore § 2264, p. 380. The existence and location of the papers are a foregone conclusion and the taxpayer adds little or nothing to the sum total of the Government's information by conceding that he in fact has the papers. Under these circumstances by enforcement of the summons "no constitutional rights are touched. The question is not of testimony but of surrender." In re Harris, 221 U.S. 274, 279 (1911).
When an accused is required to submit a handwriting exemplar he admits his ability to write and impliedly asserts that the exemplar is his writing. But in common experience, the first would be a near truism and the latter self-evident. In any event, although the exemplar may be incriminating to the accused and although he is compelled to furnish it, his Fifth Amendment privilege is not violated because nothing he has said or done is deemed to be sufficiently testimonial for purposes of the privilege. This Court has also time and again allowed subpoenas against the custodian of corporate documents or those belonging to other collective entities such as unions and partnerships and those of bankrupt businesses over claims that the documents will incriminate the custodian despite the fact that producing the documents tacitly admits their existence and their location in the
Moreover, assuming that these aspects of producing the accountant's papers have some minimal testimonial significance, surely it is not illegal to seek accounting help in connection with one's tax returns or for the accountant to prepare workpapers and deliver them to the taxpayer. At this juncture, we are quite unprepared to hold that either the fact of existence of the papers or of their possession by the taxpayer poses any realistic threat of incrimination to the taxpayer.
As for the possibility that responding to the subpoena would authenticate
The judgment of the Court of Appeals for the Fifth Circuit in No. 74-611 is reversed. The judgment of the Court of Appeals for the Third Circuit in No. 74-18 is affirmed.
MR. JUSTICE STEVENS took no part in the consideration or disposition of these cases.
MR. JUSTICE BRENNAN, concurring in the judgment.
I concur in the judgment. Given the prior access by accountants retained by the taxpayers to the papers involved in these cases and the wholly business rather than personal nature of the papers, I agree that the privilege against compelled self-incrimination did not in either of these cases protect the papers from production in response to the summonses. See Couch v. United States, 409 U.S. 322, 335-336 (1973); id., at 337 (BRENNAN, J., concurring). I do not join the Court's opinion, however, because of the portent of much of what is said of a serious crippling of the protection secured by the privilege against compelled production of one's private books and papers. Like today's decision in United States v. Miller, post, p. 435, it is but another step in the denigration of privacy principles settled nearly 100 years ago in Boyd v. United States, 116 U.S. 616
Expressions are legion in opinions of this Court that the protection of personal privacy is a central purpose of the privilege against compelled self-incrimination. "[I]t is the invasion of [a person's] indefeasible right of personal security, personal liberty and private property" that "constitutes the essence of the offence" that violates the privilege. Boyd v. United States, supra, at 630. The privilege reflects "our respect for the inviolability of the human personality and of the right of each individual `to a private enclave where he may lead a private life.' " Murphy v. Waterfront Comm'n, 378 U.S. 52, 55 (1964). "It respects a private inner sanctum of individual feeling and thought and proscribes state intrusion to extract self-condemnation." Couch v. United States, supra, at 327. See also Tehan v. United States ex rel. Shott, 382 U.S. 406, 416 (1966); Miranda v. Arizona, 384 U.S. 436, 460 (1966). "The Fifth Amendment in its Self-Incrimination Clause enables the citizen to create a zone of privacy which government may not force him to surrender to his detriment." Griswold v. Connecticut, 381 U.S. 479, 484 (1965). See also Katz v. United States, 389 U.S. 347, 350 n. 5 (1967).
The Court pays lip service to this bedrock premise of privacy in the statement that "[w]ithin the limits imposed by the language of the Fifth Amendment, which we necessarily observe, the privilege truly serves privacy interests," ante, at 399. But this only makes explicit what elsewhere highlights the opinion, namely, the view that protection of personal privacy is merely a byproduct and not, as our precedents and history teach, a factor controlling in part the determination of the scope of the privilege. This cart-before-the-horse approach is fundamentally at odds with the settled principle that the scope of the privilege is not constrained by the limits of the
That the privilege does not protect against the production of private information where there is no compulsion, or where immunity is granted, or where there is no threat of incrimination in nowise supports the Court's argument demeaning the privilege's protection of privacy. The unavailability of the privilege in those cases only evidences that, as is the case with the First and Fourth Amendments, the protection of privacy afforded by the privilege is not absolute. The critical question then is the definition of the scope of privacy that is sheltered by the privilege.
The common-law and constitutional extension of the privilege to testimonial materials, such as books and papers, was inevitable. An individual's books and papers are generally little more than an extension of his person. They reveal no less than he could reveal upon being questioned directly. Many of the matters within an individual's knowledge may as easily be retained within his head as set down on a scrap of paper. I perceive no principle which does not permit compelling one to disclose the contents of one's mind but does permit compelling the disclosure of the contents of that scrap of paper by compelling its production. Under a contrary view, the constitutional protection would turn on fortuity, and persons would, at their peril, record their thoughts and the events of their lives. The ability to think private thoughts, facilitated as it is by pen and paper, and the ability to preserve intimate memories would be curtailed through fear that those thoughts or the events of those memories would become the subjects of criminal sanctions however invalidly imposed. Indeed, it was the very reality of those fears that helped provide the historical impetus for the privilege. See Boyd v. United States, supra, at 631-632; E. Griswold, The Fifth Amendment Today 8-9 (1955); 8 J. Wigmore, Evidence § 2250, pp. 277-281 (McNaughton rev. 1961); id., § 2251, pp. 313-314; McKay, Self-Incrimination and the New Privacy, 1967 Supreme Court Review 193, 212.
Though recognizing that a subpoena served on a taxpayer involves substantial compulsion, the Court concludes that since the subpoena does not compel oral testimony or require the taxpayer to restate, repeat, or affirm the truth of the contents of the documents sought, compelled production of the documents by the taxpayer would not violate the privilege, even though the documents might incriminate the taxpayer. Ante, at 409. This analysis is patently incomplete: the threshold inquiry is whether the taxpayer is compelled to produce incriminating papers. That inquiry is not answered in favor of production merely because the subpoena requires neither oral testimony from nor affirmation of the papers' contents by the taxpayer. To be sure, the Court correctly observes that "[t]he taxpayer cannot avoid compliance with the subpoena merely by asserting that the item of evidence which he is required to produce contains incriminating writing, whether his own or that of someone else." Ante, at 410 (emphasis supplied). For it is not enough that the production of a writing, or books and papers, is compelled. Unless those materials are such as to come within the zone of privacy recognized by the Amendment, the privilege against compulsory self-incrimination does not protect against their production.
Couch v. United States expressly held that the Fifth Amendment protected against the compelled production of testimonial evidence only if the individual resisting production had a reasonable expectation of privacy with respect to the evidence. 409 U. S., at 336. Couch relied on Perlman v. United States, 247 U.S. 7
Most recently, Bellis v. United States, 417 U.S. 85 (1974), followed the approach taken in Wilson. Bellis held that the partner of a small law firm could not invoke the privilege against self-incrimination to justify his refusal to comply with a subpoena requiring production of the partnership's financial records. Bellis stated: "It has long been established . . . that the Fifth Amendment privilege against compulsory self-incrimination protects an individual from compelled production of his personal papers and effects as well as compelled oral testimony. . . . The privilege applies to the business records of the sole proprietor or sole practitioner as well as to personal documents containing more intimate information about the individual's private life." 417 U. S., at 87-88. Bellis also recognized that the Court's "decisions holding the privilege inapplicable to the records of a collective entity also reflect . . . the protection of an individual's right to a `private enclave where he may lead a private life.' . . . Protection of individual privacy was the major theme running through the Court's decision in Boyd . . . and it was on this basis that the Court in Wilson distinguished the corporate records involved in that case from the private papers at issue in Boyd." Id., at 91-92. "[C]orporate
A precise cataloguing of private papers within the ambit of the privacy protected by the privilege is probably impossible. Some papers, however, do lend themselves to classification. See generally Comment, The Search and Seizure of Private Papers: Fourth and Fifth Amendment Considerations, 6 Loyola (LA) L. Rev. 274, 300-303 (1973). Production of documentary materials created or authenticated by a State or the Federal Government, such as automobile registrations or property deeds, would seem ordinarily to fall outside the protection of the privilege. They hardly reflect an extension of the person.
Economic and business records may present difficulty in particular cases. The records of business entities generally fall without the scope of the privilege. But, as noted, the Court has recognized that the privilege extends to the business records of the sole proprietor or practitioner. Such records are at least an extension of an aspect of a person's activities, though concededly
The Court's treatment in the instant cases of the question whether the evidence involved here is within the protection of the privilege is, with all respect, most inadequate. The gaping hole is in the omission of any reference to the taxpayer's privacy interests and to whether the subpoenas impermissibly invade those interests. The observations that the "accountant's workpapers are not the taxpayer's" and "were not prepared by the taxpayer," ante, at 409, touch on matters relevant to the taxpayer's expectation of privacy, but do not of themselves determine the availability of the privilege. Wilson v. United States, 221 U. S., at 378, stated: "[T]he mere fact that
I also question the Court's treatment of the question whether the act of producing evidence is "testimonial." I agree that the act of production implicitly admits the existence of the evidence requested and possession or control of that evidence by the party producing it. It also implicitly authenticates the evidence as that identified in the order to compel. I disagree, however, that implicit admission of the existence and possession or control of the papers in this case is not "testimonial" merely because the Government could readily have otherwise proved existence and possession or control in these cases.
Nor do I consider the taxpayers' implicit authentication an insubstantial threat of self-incrimination. Actually, authentication of the papers as those described in the subpoenas establishes the papers as the taxpayers', thereby supplying an incriminatory link in the chain of evidence against them. It is not the less so because the taxpayers' accountants may also provide the link, since the protection against self-incrimination cannot, I repeat, turn on the strength of the Government's case.
This Court's treatment of handwriting exemplars is not supportive of its position. See Gilbert v. California, 388 U.S. 263 (1967). The Court has only recognized that "[a] mere handwriting exemplar . . . , like the voice or body itself, is an identifying physical characteristic outside its protection." Id., at 266-267. It is because handwriting exemplars are viewed as strictly nontestimonial, not because they are insufficiently testimonial, that the Fifth Amendment does not protect against their compelled production. Also not supportive of the Court's position is the principle that the custodian of documents of a collective entity is not protected from the act of producing those documents. Nothing in the language of those cases, either expressly or impliedly, indicates that the act of production with respect to the records of business entities is insufficiently testimonial for purposes of the Fifth Amendment. At most, those issues, though considered, were disposed of on the ground, not that production was insufficiently testimonial, but that one in control of the records of an artificial organization
MR. JUSTICE MARSHALL, concurring in the judgment.
Today the Court adopts a wholly new approach for deciding when the Fifth Amendment privilege against self-incrimination can be asserted to bar production of documentary evidence.
This technical and somewhat esoteric focus on the testimonial elements of production rather than on the content of the evidence the investigator seeks is, as MR. JUSTICE BRENNAN demonstrates, contrary to the history and traditions of the privilege against self-incrimination both in this country and in England, where the privilege originated. A long line of precedents in this Court, whose rationales if not holdings are overturned by the Court today, support the notion that "any forcible and compulsory extortion of a man's . . . private papers to be used as evidence to convict him of crime" compels him to be a witness against himself within the meaning of the Fifth Amendment to the Constitution. Boyd v. United States, 116 U.S. 616, 630 (1886). See also Bellis v. United States, 417 U.S. 85, 87 (1974); Couch v. United States, supra, at 330; Schmerber v. California, 384 U.S. 757, 763-764 (1966); Davis v. United States, 328 U.S. 582, 587-588 (1946); United States v. White, 322 U.S. 694, 698-699 (1944); Wheeler v. United States, 226 U.S. 478, 489 (1913); Wilson v. United States, 221 U.S. 361, 377 (1911).
However analytically imprecise these cases may be, they represent a deeply held belief on the part of the Members of this Court throughout its history that there
Nonetheless, I am hopeful that the Court's new theory, properly understood and applied, will provide substantially the same protection as our prior focus on the contents of the documents. The Court recognizes, as others have argued, that the act of production can verify the authenticity of the documents produced. See, e. g., United States v. Beattie, 522 F.2d 267 (CA2 1975), cert. pending, Nos. 75-407, 75-700. But the promise of the Court's theory lies in its innovative discernment that production may also verify the documents' very existence and present possession by the producer. This expanded recognition of the kinds of testimony inherent in production not only rationalizes the cases, but seems to me to afford almost complete protection against compulsory production of our most private papers.
Thus, the Court's rationale provides a persuasive basis for distinguishing between the corporate-document cases and those involving the papers of private citizens. Since the existence of corporate record books is seldom in doubt, the verification of their existence, inherent in their production, may fairly be termed not testimonial at all. On the other hand, there is little reason to assume the present existence and possession of most private papers, and certainly not those MR. JUSTICE BRENNAN places at the top of his list of documents that the privilege should protect. See ante, at 426-427 (concurring in judgment).
The Court's theory will also limit the prosecution's ability to use documents secured through a grant of immunity. If authentication that the document produced is the document demanded were the only testimony inherent in production, immunity would be a useful tool for obtaining written evidence. So long as a document obtained under an immunity grant could be authenticated through other sources, as would often be possible, reliance on the immunized testimony—the authentication—and its fruits would not be necessary, and the document could be introduced. The Court's recognition that the act of production also involves testimony about the existence and possession of the subpoenaed documents mandates a different result. Under the Court's theory, if the document is to be obtained the
In short, while the Court sacrifices our pragmatic, if somewhat ad hoc, content analysis for what might seem an unduly technical focus on the act of production itself, I am far less pessimistic than MR. JUSTICE BRENNAN that this new approach signals the end of Fifth Amendment protection for documents we have long held to be privileged. I am not ready to embrace the approach myself, but I am confident in the ability of the trial judges who must apply this difficult test in the first instance to act with sensitivity to our traditional concerns in this uncertain area.
For the reasons stated by MR. JUSTICE BRENNAN, I concur in the judgment of the Court.
First Amendment values are also plainly not implicated in these cases.
In No. 74-611, the taxpayer did not intervene, and his rights have been asserted only through his lawyer. The parties disagree on the question whether an attorney may claim the Fifth Amendment privilege of his client. We need not resolve this question. The only privilege of the taxpayer involved here is the attorney-client privilege, and it is universally accepted that the attorney-client privilege may be raised by the attorney, C. McCormick, Evidence § 92, p. 193, § 94, p. 197 (2d ed. 1972) (hereinafter McCormick); Republic Gear Co. v. Borg-Warner Corp., 381 F.2d 551 (CA2 1967); Bouschor v. United States, 316 F.2d 451 (CA8 1963); Colton v. United States, 306 F.2d 633 (CA2 1962); Schwimmer v. United States, 232 F.2d 855 (CA8), cert. denied, 352 U.S. 833 (1956); Baldwin v. Commissioner, 125 F.2d 812 (CA9 1942).
"Some tests seemingly directed to obtain `physical evidence,' for example, lie detector tests measuring changes in body function during interrogation, may actually be directed to eliciting responses which are essentially testimonial. To compel a person to submit to testing in which an effort will be made to determine his guilt or innocence on the basis of physiological responses, whether willed or not, is to evoke the spirit and history of the Fifth Amendment. Such situations call to mind the principle that the protection of the privilege `is as broad as the mischief against which it seeks to guard.' . . ."
The proposition, ante, at 409, that Boyd's holding ultimately rested on the Fourth Amendment could not be more incorrect. Boyd did observe that the purposes to be served by the Fourth and Fifth Amendments shed light on each other, 116 U. S., at 633, but the holdings that the compelled production of the papers involved there violated the Fourth and Fifth Amendments were independent of each other. In holding that "a compulsory production of the private books and papers of the owner of goods sought to be forfeited in such a suit is compelling him to be a witness against himself, within the meaning of the Fifth Amendment to the Constitution, and is the equivalent of a search and seizure—and an unreasonable search and seizure—within the meaning of the Fourth Amendment," id., at 634-635, the Court plainly did not make the Fourth Amendment violation a predicate, let alone an essential predicate, for its holding that there was also a Fifth Amendment violation. The Court is incorrect in suggesting that "the rule against compelling production of private papers rested on the proposition that seizures of or subpoenas for `mere evidence,' including documents, violated the Fourth Amendment and therefore also transgressed the Fifth." Ante, at 409. The relation of the Fourth Amendment to the Fifth Amendment violation in United States v. Lefkowitz, 285 U.S. 452 (1932); Agnello v. United States, 269 U.S. 20 (1925); and Gouled v. United States, 255 U.S. 298 (1921), was merely that the illegal searches and seizures in those cases were held to establish the element of compulsion essential to a Fifth Amendment violation. See ante, at 399-400, n. 5. Even if the Fourth Amendment violations were now held not to establish the element of Fifth Amendment compulsion, it, of course, would not follow that the Fifth Amendment's protection against compelled production of incriminating private papers is lost.
Furthermore, that purely evidentiary material may have been seized in those cases was neither relied upon to establish the Fourth Amendment violations nor, in turn, to establish the Fifth Amendment violations. Indeed, in Agnello, contraband, not mere evidence, was illegally seized. Subsequent decisions modifying the "mere evidence" rule, therefore, have left untouched the Fifth Amendment's prohibition against the compelled production of incriminating testimonial evidence. Indeed, citing Warden v. Hayden, 387 U.S. 294 (1967), the Court notes, that the question is open whether the legal search and seizure of some forms of testimonial evidence would violate the Fifth Amendment, ante, at 407 n. 9. Warden v. Hayden observed: "The items of clothing involved in this case are not `testimonial' or `communicative' in nature, and their introduction therefore did not compel respondent to become a witness against himself in violation of the Fifth Amendment. . . . This case thus does not require that we consider whether there are items of evidential value whose very nature precludes them from being the object of a reasonable search and seizure." 387 U. S., at 302-303. That observation was plainly addressed not to application of the Fourth Amendment but to application of the Fifth.
Contrary to the Court's intimations, ante, at 407-408, neither Katz v. United States, 389 U.S. 347 (1967); Osborn v. United States, 385 U.S. 323 (1966); nor Berger v. New York, 388 U.S. 41 (1967), all involving the Fourth Amendment, lends support to an argument that the Fifth Amendment would not protect the seizure of the private papers of a person suspected of crime. Fifth Amendment challenges to the seizure and use of private papers were not involved in those cases.