However, no error was preserved on this question by either objecting to instructions given or ob- jecting to the failure to give instructions that may have been tendered. The district judge complied with the mandates of Fed. P. 30 in regard to the for- mulation of instructions. This issue was not raised in the district court and will not be considered for the first time here. Materiality inheres in a violation of sec.
Materiality is a question of law for the district court.
No error is here preserved on the issue of materiality. Title 18 U.S.C. sec. 1001 prohibits knowingly and willfully making a false statement which is material to a matter within the jurisdiction of the department or agency of the United States. 1001 is the judicial expression of the view that the statute is generally not applicable to false state- ments which are essentially exculpatory denials of criminal activity. The exculpatory denial exception is rooted in two separate but complementary concerns which courts have employed to create the exception and to define its scope.