ment evidence or documents that the defense may use to refresh a witness's recollection during the government's case-in-chief. See United States v. Medearis, 380 F.3d 1049, 1057 (8th Cir. 2004) (Rule 16(b)(1)(A) does not require disclosure of impeachment evidence); United States v. Moore, 208 F.3d 577,