Mr. Chief Justice Vinson
delivered the opinion of the Court.
This case arises out of an investigation by the regularly convened grand jury of the United States District Court for the District of Colorado. The books and records of the Communist Party of Denver were sought as necessary to that inquiry and were the subject of questioning by the grand jury. In September, 1948, petitioner, in response to a subpoena, appeared before the grand jury. She testified that she held the position of Treasurer of the Communist Party of Denver until January, 1948, and that, by virtue of her office, she had been in possession of membership lists and dues records of the Party. Petitioner denied having possession of the records and testified that she had turned them over to another. But she refused to identify the person to whom she had given the Party’s books, stating to the court as her only reason: “I don’t feel that I should subject a person or persons to the same thing that I’m going through.” The court thereupon committed petitioner to the custody of the marshal until ten o’clock the next morning, expressly advising petitioner of her right to consult with counsel.
The next day, counsel for petitioner informed the court that he had read the transcript of the prior day’s proceedings and that, upon his advice, petitioner would answer the questions to purge herself of contempt. However, upon reappearing before the grand jury, petitioner again refused to answer the question. The following day she was again brought into court. Called before the district judge immediately after he had heard oral argument concerning the privilege against self-incrimination in another case, petitioner repeated her refusal to answer the question, asserting this time the privilege against self-incrimination. After ruling that her refusal was not privileged, the district judge imposed a sentence of four months for contempt. The Court of Appeals for the Tenth Circuit affirmed, 179 F. 2d 559 (1950), and we granted certiorari, 339 U. S. 956 (1950).
If petitioner desired the protection of the privilege against self-incrimination, she was required to claim it. United States v. Monia, 317 U. S. 424, 427 (1943). The privilege "is deemed waived unless invoked.” United States v. Murdock, 284 U. S. 141, 148 (1931). Furthermore, the decisions of this Court are explicit in holding that the privilege against self-incrimination “is solely for the benefit, of the witness,” and “is purely a personal privilege of the witness.” Petitioner expressly placed her original declination to answer on an untenable ground, since a refusal to answer cannot be justified by a desire to protect others from punishment, much less to protect another from interrogation by a grand jury. Petitioner’s claim of the privilege against self-incrimination was pure afterthought. Although the claim was made at the time of her second refusal to answer in the presence of the court, it came only after she had voluntarily testified to her status as an officer of the Communist Party of Denver. To uphold a claim of privilege in this case would open the way to distortion of facts by permitting a witness to select any stopping place in the testimony.
The privilege against self-incrimination, even if claimed at the time the question as to the name of the person to whom petitioner turned over the Party records was asked, would not justify her refusal to answer. As a preliminary matter, we note that petitioner had no privilege with respect to the books of the Party, whether it be a corporation or an unincorporated association. Books and records kept “in a representative rather than in a personal capacity cannot be the subject of the personal privilege against self-incrimination, even though production of the papers might tend to incriminate [their keeper] personally.” United States v. White, 322 U. S. 694, 699 (1944). Since petitioner’s claim of privilege cannot be asserted in relation to the books and records sought by the grand jury, the only claim for reversal of her conviction rests on the ground that mere disclosure of the name of the recipient of the books tends to incriminate.
In Patricia Blau v. United States, 340 U. S. 159 (1950), we held that questions as to connections with the Communist Party are subject to the privilege against self-incrimination as calling for disclosure of facts tending to criminate under the Smith Act. But petitioner’s conviction stands on an entirely different footing, for she had freely described her membership, activities and office in the Party. Since the privilege against self-incrimination presupposes a real danger of legal detriment arising from the disclosure, petitioner cannot invoke the privilege where response to the specific question in issue here would not further incriminate her. Disclosure of a fact waives the privilege as to details. As this Court stated in Brown v. Walker, 161 U. S. 591, 597 (1896):
“Thus, if the witness himself elects to waive his privilege, as he may doubtless do, since the privilege is for his protection and not for that of other parties, and discloses his criminal connections, he is not permitted to stop, but must go on and make a full disclosure."
Following this rule, federal courts have uniformly held that, where criminating facts have been voluntarily revealed, the privilege cannot be invoked to avoid disclosure of the details. The decisions of this Court in Arndstein v. McCarthy, 254 U. S. 71 (1920), and McCarthy v. Arndstein, 262 U. S. 355 (1923), further support the conviction in this case for, in sustaining the privilege on each appeal, the Court stressed the absence of any previous “admission of guilt or incriminating facts,” and relied particularly upon Brown v. Walker, supra, and Foster v. People, 18 Mich. 266 (1869). The holding of the Michigan court is entirely apposite here:
“[WJhere a witness has voluntarily answered as to materially criminating facts, it is held with uniformity that he cannot then stop short and refuse further explanation, but must disclose fully what he has attempted to relate.” 18 Mich, at 276.
Requiring full disclosure of details after a witness freely testifies as to a criminating fact does not rest upon a further “waiver” of the privilege against self-incrimination. Admittedly, petitioner had already “waived” her privilege of silence when she freely answered criminating questions relating to her connection with the Communist Party. But when petitioner was asked to furnish the name of the person to whom she turned over Party records, the court was required to determine, as it must whenever the privilege 'is claimed, whether the question presented a reasonable danger of further crimination in light of all the circumstances, including any previous disclosures. As to each question to which a claim of privilege is directed, the court must determine whether the answer to that particular question would subject the witness to a “real danger” of further crimination. After petitioner’s admission that she held the office of Treasurer of the Communist Party of Denver, disclosure of acquaintance with her successor presents no more than a “mere imaginary possibility” of increasing the danger of prosecution.
Petitioner’s contention in the Court of Appeals and in this Court has been that, conceding her prior voluntary crimination as to one element of proof of a Smith Act violation, disclosure of the name of the recipient of the Party records would tend to incriminate as to the different crime of conspiracy to violate the Smith Act. Our opinion in Patricia Blau v. United States, supra, at 161, explicitly rejects petitioner’s argument for reversal here in its holding that questions relating to activities in the Communist Party are criminating both as to “violation of (or conspiracy to violate) the Smith Act.” Of course, at least two persons are required to constitute a conspiracy, but the identity of the other members of the conspiracy is not needed, inasmuch as one person can be convicted of conspiring with persons whose names are unknown.
Affirmed.
Mb. Justice Clark took no part in the consideration or decision of this case.
Transcript, p. 39 (September 21,1948):
“The Court: Now, what is the question ?
“Mr. Goldschein: Who has the books and records of the Communist Party of Denver now. Who did Mrs. Rogers give those books up to as she says she gave them up in January of this year.
“The Court: Do you care to answer that question, madam?
“Mrs. Rogers: I do not.
“TheCourt: What?
“Mrs. Rogers: I do not, and that’s what I told them.
“The Court: Why won’t you answer ?
“Mrs. Rogers: I don’t feel that I should subject a person or persons to the same thing that I’m going through.
“The Court: It is the order or finding of the Court that you should answer those questions. Now, will you do that ?
“Mrs. Rogers: No.”
Transcript, p. 40 (September 21,1948):
“The Court: You will be detained until tomorrow morning until ten o’clock. In the meantime, you may consult counsel and have a hearing tomorrow morning at ten o’clock on your reasons for refusal to answer questions. '
“Mrs. Rogers: I can consult counsel between now and then?
“The Court: Yes, but you will be in the custody of the marshal all the time. Get your counsel and bring him over here if you want to, but you will have to be in the custody of the marshal and spend the night in jail, I’m afraid.”
Transcript, pp. 43, 49 (September 22,1948):
“Mr. Menin [After entering his appearance on behalf of petitioner] : In regard to the witness Rogers, I’ve read the transcript of what has transpired in court here yesterday; and I believe that upon my advice she will answer questions which were propounded to her.
“Mr. Menin: As to the witness Jane Rogers, I think she will purge herself of her contempt by answering the questions.
“The Court: In the case of the witness Rogers, then, the order of the Court is that she return to the Grand Jury room and if she purges herself of contempt, then upon bringing the matter back to the Court, she will be discharged. In the meantime, she will remain in custody.”
“No person. . . . shall be compelled in any criminal case to be a witness against himself . . . .” U. S. Const., Amend. V. The proceedings leading to the claim of privilege by petitioner appear at Transcript, pp. 77-78 (September 23,1948):
“The Court: . . . Madam, do you still persist in not answering these questions?
"Mrs. Rogers: Well, on the basis of Mr. Menin’s statements this morning—
“The Court: Will you please answer the question yes or no?
“Mrs. Rogers: Well, I think that’s rather undemocratic[.] I’m a very honest person. Would you mind letting me consider—
“The Court: Make any statement you wish.
“Mrs. Rogers: Well, as I said before, I’m a very honest person and I’m not acquainted with the tricks of legal procedure, but I understand from the reading of these cases this morning that I am — and I do have a right to refuse to answer these questions, on the basis that they would tend to incriminate me, and you read it yourself, that I have a right to decide that.
“The Court: You have not the right to say.
“Mrs. Rogers: According to what you read, I do. I stand on that.
“The Court: All right. If you will make no changes, it is the judgment and sentence of the court you be confined to the custody of the Attorney General for four months. Call the next case.”
Citing Vajtauer v. Commissioner of Immigration, 273 U. S. 103, 113 (1927). See Smith v. United States, 337 U. S. 137, 147 (1949) ; Corwin, The Supreme Court’s Construction of the Self-Incrimination Clause, 29 Mich. L. Rev. 1, 198-199 (1930).
United States v. Murdock, 284 U. S. 141, 148 (1931).
Hale v. Henkel, 201 U. S. 43, 69 (1906). McAlister v. Henkel, 201 U.S. 90, 91 (1906).
Brown v. Walker, 161 U. S. 591, 609 (1896); Hale v. Henkel, 201 U. S. 43, 69-70 (1906).
Wilson v. United States, 221 U. S. 361 (1911); Wheeler v. United States, 226 U. S. 478 (1913); Grant v. United States, 227 U. S. 74 (1913); Essgee Co. v. United States, 262 U. S. 151 (1923).
Brown v. United States, 276 U. S. 134 (1928); United States v. White, 322 U. S. 694 (1944). Cf. United States v. Fleischman, 339 U. S. 349, 358 (1950).
See also the cases cited in notes 7 and 8, supra. The privilege does not attach to the books of an organization, whether or not the books in question are “required records” of the type considered in Shapiro v. United States, 335 U. S. 1 (1948).
Membership in the Communist Party was not, of itself, a crime at the time the questions in this case were asked. And Congress has since expressly provided, in the Internal Security Act of 1950, Act of Sept. 23, 1950, 64 Stat. 987, 992, §4 (f), that “neither the holding of office nor membership in any Communist organization by any person shall constitute per se a violation of subsection (a) or subsection (c) of this section or of any other criminal statute.” We, of course, express no opinion as to the implications of this legislation upon the issues presented by these cases.
Quoted with approval in Powers v. United States, 223 U. S. 303, 314 (1912).
United States v. St. Pierre, 132 F. 2d 837 (C. A. 2d Cir., 1942); Buckeye Powder Co. v. Hazard Powder Co., 205 F. 827, 829 (D. C. Conn., 1913).
262 U. S. at 359 (emphasis supplied). The Arndstein appeals, like the present case, arose out of an involuntary examination. The Court reserved, as we do here, the problems arising out of a possible abuse of the privilege against self-incrimination in adversary proceedings. Compare state court decisions collected in 147 A. L. R. 255 (1943).
VIII Wigmore, Evidence (1940), §2276, quotes from Foster v. People, 18 Mich. 266 (1869), as authoritative and summarizes the law as follows:
“The case of the ordinary witness can hardly present any doubt. He may waive his privilege; this is conceded. He waives it by exercising his option of answering; this is conceded. Thus the only inquiry can be whether, by answering as to fact X, he waived it for fact Y. If the two are related facts, parts of a whole fact forming a single relevant topic, then his waiver as to a part is a waiver as to the remaining parts; because the privilege exists for the sake of the criminating fact as a whole.” (Emphasis in original.)
Heike v. United States, 227 U. S. 131, 144 (1913). Brown v. Walker, 161 U. S. 591, 600 (1896).
Mason v. United States, 244 U. S. 362, 366 (1917).
United States v. St. Pierre, 132 F. 2d 837 (C. A. 2d Cir., 1942), presented a closer question since the “detail” which St. Pierre was required to divulge would identify a person without whose testimony St. Pierre could not have been convicted of a crime. We, of course, do not here pass upon the precise factual question there decided by the Court of Appeals.
Browne v. United States, 145 F. 1, 13 (C. A. 2d Cir., 1905); Donegan v. United States, 287 F. 641, 648 (C. A. 2d Cir., 1922); Pomerantz v. United States, 51 F. 2d 911, 913 (C. A. 3d Cir., 1931); Grove v. United States, 3 F. 2d 965, 967 (C. A. 4th Cir., 1925); McDonald v. United States, 9 F. 2d 506, 507 (C. A. 8th Cir., 1925) ; Rosenthal v. United States, 45 F. 2d 1000, 1003 (C. A. 8th Cir., 1930); Didenti v. United States, 44 F. 2d 537, 538 (C. A. 9th Cir., 1930). See also Feder v. United States, 257 F. 694, 697 (C. A. 2d Cir., 1919); Worthington v. United States, 64 F. 2d 936, 939 (C. A. 7th Cir., 1933).