Stanley Forman Reed,
Smith v. United States (337 U.S. 137…
“ Nor do we see any reason why claim of privilege to all or any part of testimony may not be withdrawn. Although the privilege against self-incrimination must be claimed, when claimed it is guaranteed by the Constitution. Thereafter only absolute immunity from federal criminal prosecution is sufficient to compel the desired testimony. Waiver of constitutional rights, however, is not lightly to be inferred. [11] A witness cannot properly be held after claim to have waived his privilege and consequent immunity upon vague and uncertain evidence. ”
