28 CFR § 21.1(c) [28 CFR PART 21—WITNESS FEES]
(c) Judicial proceeding.
Any action or suit, including any condemnation, preliminary, informational or other proceeding of a judicial nature. Examples of the latter include, but are not limited to, hearings and conferences before a committing court, magistrate, or commission, grand jury proceedings, pre-trial conferences, depositions, and coroners' inquests. It does not include information or investigative proceedings conducted by a prosecuting attorney for the purpose of determining whether an information or charge should be made in a particular case. The judicial proceeding may be in the District of Columbia, a State, or a territory or possession of the United States including the Commonwealth of Puerto Rico or the Trust Territory of the Pacific Islands.