((a)) Wherever in this title it is an element of an offense that—

((1)) any property was embezzled, robbed, stolen, converted, taken, altered, counterfeited, falsely made, forged, or obliterated; and

((2)) the defendant knew that the property was of such character;

((b)) For purposes of this section, the term “official representation” means any representation made by a Federal law enforcement officer (as defined in section 115) or by another person at the direction or with the approval of such an officer.