"The Government need not allege the subordinate evidentiary facts by which it intends to prove the 'in furtherance' element of the crime charged, and an indictment setting out the mailings charged and alleging that they were in furtherance of the scheme should not be dismissed as insufficient on its face unless there is no conceivable evidence that the Government could produce at trial to substantiate its 'in furtherance' allegation." United States v. Castor, 558 F.2d 379, 385 (7th Cir. 1977), cert. denied, 434 U.S. 1010 (1978). In Castor, the court observed the following concerning the requirement of alleging that the mailings were in furtherance of the scheme:
The question is not whether the indictment particularly alleges sufficient facts from which a jury could find that the mailings charged were in furtherance of the scheme, but rather whether the Government conceivably could produce evidence at trial showing that the designated mailings were for the purposes of executing the scheme. United States v. Sampson, 371 U.S. 75, 76, 83 S.Ct. 173, 9 L.Ed.2d 136 (1962). The resolution of the question of whether the mailings alleged were in furtherance of the scheme must await trial "unless it so convincingly appears on the face of the indictment that as a matter of law there need be no necessity for such delay." United States v. Feinberg, 50 F. Supp. 976, 977 (E.D.N.Y. 1973), aff'd, 140 F.2d 592 (2d Cir.), cert. denied, 322 U.S. 726, 64 S.Ct. 943, 88 L.Ed. 1562 (1944).
Id. at 384-85.
[cited in USAM 9-43.100]