“To prove a violation of Section 1512(c)(2), the Government must establish that the defendant impaired the availability or integrity for use in an official proceeding of rec-ords, documents, objects, or as we earlier explained, other things used in the proceeding, or attempted to do so. See supra, at 9. The judgment of the D. C. Circuit is therefore vacated, and the case is remanded for further proceedings consistent with this opinion. On remand, the D. C. Circuit may assess the sufficiency of Count Three of Fischer’s indictment in light of our interpretation of Section 1512(c)(2),”
