How to Object to a Grand Jury Subpoena

The Fifth Circuit recently summarized the sometimes-confusing law about when an adverse ruling about a grand-jury subpoena may be appealed:

Our jurisdiction is generally limited to reviewing final decisions of a district court. This rule applies to appeals of orders issued in grand jury proceedings. There are two exceptions. First, if a witness chooses not to comply with a grand jury subpoena compelling production of documents and is held in contempt, that witness may immediately appeal the court’s interlocutory order. Second, under what is called the Perlman doctrine, a party need not be held in contempt prior to filing an interlocutory appeal if “the documents at issue are in the hands of a third party who has no independent interest in preserving their confidentiality.

In re Grand Jury Subpoena, No. 21-30705 (Dec. 14, 2022). (At least in theory, a mandamus petition may also be available in this setting, see generally David Coale, Five Years After Mohawk, 34 Rev. Litig. 1 (2015)).