Here are the materials in United States v. Mitchell (W.D. N.Y.):
74 MJ R&R Denying Omnibus Motion
116 US Response to Motion to Dismiss — Immunity
123 Mitchell Objections to 119
137 US Response to Motion to Dismiss — Jurisdiction
138 Mitchell Brief on Major Crimes Act
140 DCT Order Denying Motion to Dismiss
Prior federal case challenging his banishment is here.