The Sixth Amendment to the U.S. Constitution gives criminal defendants the subpoena power to compel the attendance of such witness.
The Court has had little occasion to discuss the contours of the Compulsory Process Clause. The first and most celebrated analysis came from a Virginia federal court in 1807, during the treason and misdemeanor trials of Aaron Burr. Chief Justice Marshall, who presided as trial judge, ruled that Burr's compulsory process rights entitled him to serve a subpoena on President Jefferson, requesting the production of allegedly incriminating evidence. The evidence consisted of a letter that was sent to President Jefferson by General James Wilkinson that allegedly showed that Burr was planning to invade Mexico and set up a separate government under his control. After being ordered to do so, Jefferson eventually turned over an edited version of the letter. For an excellent summary of the Burr case and its implications for compulsory process, see Westen 101-108. United States v. Burr, 25 F.Cas. 30, 35 (No. 14,692d) (CC Va. 1807). Despite the implications of the Burr decision for federal criminal procedure, the Compulsory Process Clause rarely was a factor in this Court's decisions during the next 160 ...