In United States v. Cotto (available here), the Circuit (Leval, joined by Livingston and Bianco) held that the offense of witness retaliation, 18 U.S.C. § 1513(b)(1), does not require proof that the defendant knew the federal nature of the proceeding in which the witness testified.
Section 1513(b)(1) applies to one who “knowingly engages in any conduct, and thereby causes bodily injury to another person … or threatens to do so, with intent to retaliate against any person for … the attendance of a witness or party at an official proceeding, or any testimony given … by a witness in an official proceeding.” An “official proceeding” is defined to include “a proceeding before a court of judge of the United States.” 18 U.S.C. § 1515(a)(1). Section 1513(b)(1) does require proof “that the defendant acted with retaliatory intent arising out of a person’s testimony at an ‘official proceeding,’ and that the …