Although 18 U.S.C. § 1001 is often referred to as a false
statement
statute, its scope extends beyond statements. The statute proscribes the
acts
of making false statements, falsifying, concealing or covering up. The
statute
also covers half-truths if there is a duty to speak the truth. See
generallyUnited States v. Lutwak, 195 F.2d 748 (7th Cir. 1948),
aff'd, 344 U.S. 604 (1953).
Concealment and cover-up are essentially identical concepts and
often
result from falsification. These acts need not have any relation to a
statement
or representation. A concealment may involve a failure to disclose or
partial
disclosures of information required on an application form; however, when
using
such a theory, the government must prove that the defendant had a duty to
disclose the facts in question at the time of the alleged concealment of
them.
United States v. Irwin, 654 F.2d 671, 678-79 (10th Cir. 1981),
cert.
denied, 455 U.S. 1016 (1982). Concealment may also involve a merely
physical
act of concealment such as transferring inspection stamps, changing numbers
on
bottles to conceal rejection, conceal use of certain drugs, or using false
stamps
to conceal ownership of tobacco. Some courts have required that the
government
be prepared to prove that the "concealment by trick" consisted of
affirmative
acts. United States v. London, 550 F.2d 206 (5th Cir. 1977).