As amended in 1966, Rule 21(b) allows the transfer of a criminal case to any district without being limited to a transfer to a district in which venue would lie as required under the original rule, Jones v. Gasch, 404 F.2d 1231 (D.C. Cir. 1967), cert. denied, 390 U.S. 1028 (1968).
The court's determination as to whether to grant the motion to transfer rests in the court's sound discretion, unlike transfer under Rule 21(a) which is mandatory after the court is satisfied that prejudice makes transfer necessary. See United States v. Griesa, 481 F.2d 276, 284 (2nd Cir. 1973) (dissenting opinion). The trial court's discretion will not be overturned unless clearly abused, Jones v. Gasch, 404 F.2d 1231; United States v. Jessup, 38 F.R.D. 42 (M.D.Tenn. 1965); thus defendant carries the burden of showing substantial balance of inconvenience to warrant finding that a transfer would be in the interest of justice. United States v. Benjamin, 623 F. Supp. 623 (D.D.C. 1985); United States v. Oster, 580 F. Supp. 599 (S.D.W.Va. 1984); United States v. Baltimore and O.R.R., 538 F. Supp. 200 (D.D.C. 1982); United States v. Jones, 43 F.R.D. 511 (D.D.C. 1967), affirmed, 404 F.2d 1231 (D.D.C. 1967), cert. denied, 390 U.S. 1029 (1968).
An appellate court cannot substitute its judgment for that of the trial court by exercising de novo examination of the motion to transfer, Platt v. Minnesota Mining & Manufacturing Co., 376 U.S. 240 (1964). A mandamus action by the government to vacate a transfer order, being an extraordinary action reserved for extraordinary causes, will not prevail except upon a clear showing that the trial court has acted in excess of its authority or clearly abused its discretion. United States v. Clark, 360 F. Supp. 936 (S.D.N.Y. 1973). Compare Auerbach v. United States, 347 F.2d 742 (5th Cir.), cert. denied, 382 U.S. 958 (1965) (the defendant had no relief from the court's order transferring back the case on its own motion, when the defendant appealed the retransfer order and it was held the order was not final and thus not appealable). See also United States v. Harris, 707 F.2d 653 (2nd Cir. 1983); United States v. Angiulo, 497 F.2d 440 (1st Cir. 1974), cert. denied, 419 U.S. 896; United States v. Garber, 413 F.2d 284 (2nd Cir. 1969); Holdsworth v. United States, 179 F.2d 933 (1st Cir. 1950) (dismissing defendant's appeal of retransfer order and holding transferee court cannot review transfer order).