What is the inherent authority of a federal court to expunge a criminal record?

As to inherent authority, federal courts have "inherent authority to expunge criminal records in appropriate and extraordinary cases." Crowell at 793. Only when a defendant "has succeeded in getting her conviction vacated, a district court may then determine whether the petitioner has asserted circumstances extraordinary and unusual enough that would merit expungement of her criminal judicial records." Crowell at 796. Thus, a federal court's inherent authority to expunge a criminal record "is limited to expunging the record of an unlawful arrest or conviction, or to correcting a clerical error." United States v. Sumner, 226 F.3d. 1005, 1014 (9th Cir. 2000). Furthermore, "even where a conviction has been held unlawful and vacated, expungement remains a narrow, extraordinary exception, one appropriately used only in extreme circumstances." Crowell at 796 (internal citation and quotations omitted).²