Potter Stewart,
Brown v. United States (359 U.S. 41…
“ A grand jury is clothed with great independence in many areas, but it remains an appendage of the court, powerless to perform its investigative function without the court's aid, because powerless itself to compel the testimony of witnesses. It is the court's process which summons the witness to attend and give testimony, and it is the court which must compel a witness to testify if, after appearing, he refuses to do so.When the petitioner first refused to answer the grand jury's questions, he was guilty of no contempt. ”
