“As I continue my investigation into whether the independence of the Inspector General was undermined by Amtrak officials, I want to make sure I have any and all information Amtrak wants to provide,” Grassley said. “The allegations are serious, including third parties being told to first send documents under subpoena by the Inspector General to Amtrak for review, and the Inspector General being chastised for communicating directly with congressional appropriations and authorizing committees . . .”