Law360, New York ( March 17, 2015, 10:28 AM EDT) -- In a recent emphatic opinion in an unheralded visa fraud criminal conspiracy case, a federal district court judge abruptly invalidated a common pretrial subpoena practice of federal prosecutors in the District of Columbia (and perhaps defense counsel and prosecutors nationwide). In United States v. Vo (D.D.C. Jan. 15, 2015), Judge Emmet G. Sullivan rejected the U.S. attorney's office's "longstanding practice of 'inviting' subpoenaed parties to make a pretrial production to it directly" without court approval. Judge Sullivan found instead that in the absence of court approval, Federal Rule of Criminal Procedure 17(c) prohibits parties from using a subpoena (directly or indirectly) to obtain the production of material prior to the day of trial (or a particular hearing)....