Is a grand jury investigation a judicial proceeding?

In order to violate 18 U.S.C. 1503(a), a defendant must have acted with an intent to influence ... grand jury proceedings, not to influence an investigation independent of the ... grand jury's authority. United States v. Aguilar , 515 U.S. 593, 599, 115 S.Ct. 2357, 2362, 132 L.Ed.2d 520 (1995). This court has already held that a grand jury investigation constitutes a judicial proceeding for purposes of 1503. United States v. Duran , 41 F.3d 540, 544 (9th Cir. 1994) ; see also United States v. Macari , 453 F.3d 926, 936 (7th Cir. 2006). Thus, the district court's use of the phrase grand jury investigation, rather than grand jury proceeding, was neither misleading nor an abuse of discretion in these circumstances.