made freely, voluntarily, and without compulsion or inducement of any
sort.[59] But in McNabb _v._ United States the Court[60] reversed a
conviction in a federal court, based on a confession obtained by
questioning the defendants for prolonged periods in the absence of
friends and counsel and without their being brought before a
commissioner or judicial officer, as required by law. Without purporting
to decide the constitutional issue, Justice Frankfurter's opinion urged
the duty of the Court, in supervising the conduct of the lower federal
courts, to establish and maintain "civilized standards of procedure and
evidence."[61] An individual who has acquired income by illicit means is
not excused from making out an income tax return because he might
thereby expose himself to a criminal prosecution by the United States.
"He could not draw a conjurer's circle around the whole matter," said
Justice Holmes, "by his own declaration that to write any word upon the
government blank would bring him into danger of the law."[62] But a
witness called to testify before a federal grand jury as to his
relations with the Communist Party cannot, in view of existing
legislation touching the subject, be compelled to answer.[63]he clause
does not require the exclusion of the body of an accused as evidence of
his identity;[64] but the introduction into evidence against one who was
being prosecuted by a State for illegal possession of morphine of two
capsules which he had swallowed and had then been forced by the police
to disgorge, was held to violate due process of law.[65]

A bankrupt is not deprived of his constitutional right not to testify
against himself by an order requiring him to surrender his books to a
duly authorized receiver.[66] He may not object to the use of his books
and papers as incriminating evidence against him while they are in the
custody of the bankruptcy court;[67] nor may he condition their delivery
by requiring a guaranty that they will not be used as incriminating
evidence.[68] The filing of schedules by a bankrupt does not waive his
right to refuse to answer questions pertaining to them when to do so may
incriminate him.[69] A disclosure, not amounting to an actual admission
of guilt or of incriminating facts, does not deprive him of the
privilege of stopping short in his testimony whenever it may fairly tend
to incriminate him.[70] The rule against self-incrimination may be
invoked by a bankrupt (in the absence