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); 10 to the giving of handwriting exemplars, Gilbert v. California, 388 U.S. 263, 265 -267 (1967); voice exemplars, United States v. Wade, 388 U.S. 218, 222 -223 (1967); or the donning of a blouse worn by the perpetrator, Holt v. United States, 218 U.S. 245 (1910). Furthermore, despite Boyd, neither a partnership nor the individual partners are shielded from compelled production of partnership records on self-incrimination grounds. Bellis v. United States, 417 U.S. 85 (1974). It would appear that under that case the precise claim sustained in Boyd would now be rejected for reasons not there considered.
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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 [425 U.S. 391, 410] testimonial evidence, either of the taxpayers or of anyone else. 11 The 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.