Whether 18 U.S.C. § 111's prohibition on "resist[ing], opposing], impeding], intimidat[ing], or interfer[ing]" with federal officers while they are "engaged in or on account of the performance of" their duties is limited to the intentional infliction of violence against the officer.

Whether 18 U.S.C. § 111's prohibition on interfering with federal officers requires intentional violence or can include inadvertent contact