the omnibus clause of the predecessor statute to § 1503 in the context of determining when a proceeding begins, the Supreme Court held that "it must be necessary for the accused to have knowledge or notice or information of the pendency of proceedings in the United States court, or the progress of the administration of justice therein, before he can be found guilty of obstructing, or impeding, or endeavoring to obstruct or impede the same.” 148 U.S. at 205, 13 S.Ct. 542. Since then, the Supreme Court has approved the recognition of certain “metes and bounds on the very broad language of the catchall provision” and has required some "nexus” between the misconduct and the administration of justice. United States v. Aguilar, 515 U.S. 593, 599, 600, 115 S.Ct. 2357, 132 L.Ed.2d 520 (1995) (<HOLDING>). According to the "nexus” analysis, "the act
holding that under california law tjestifying before a grand jury charged with investigating corruption is one part of an officers job and therefore any speech huppert gave during his grand jury testimony was pursuant to his duties as a police officer holding that where witness refused to take the oath and testify his grand jury testimony should not have been admitted because he was not subject to cross examination before the grand jury recognizing that although no obstruction occurs when an individual lies to fbi agents who might or might not testify before a grand jury it may occur if the agents acted as an arm of the grand jury or indeed that the grand jury had even summoned the testimony of these particular agents holding that a defendants false grand jury testimony was insufficient to establish perjury where the defendant was called before the grand jury for the mere purpose of laying the foundation for a perjury prosecution such testimony was immaterial to the grand jurys purpose holding that uttering false statements to an investigating agent  who might or might not testify before a grand jury is insufficient to make out violation of  1503s catchall provision