The Assistant Attorney General, the Bureau of Justice Assistance, the National Institute of Justice, and the Bureau of Justice Statistics may appoint (to be assigned or employed on an interim or as-needed basis) such hearing examiners (who shall, if so designated, be understood to be comprised within the meaning of “special government employee” under section 202 of title 18 (without regard to the days limitation prescribed therein), but shall, in no event, be understood to be (or to have the authority of) officers of the United States) or administrative law judges or request the use of such administrative law judges selected by the Office of Personnel Management pursuant to section 3344 of title 5, as shall be necessary or convenient to assist them in carrying out their respective powers and duties under any law administered by or under the Office. The Assistant Attorney General, the Bureau of Justice Assistance, the National Institute of Justice, and the Bureau of Justice Statistics or upon authorization, any member thereof, or (subject to such limitations as the appointing authority may, in its sole discretion, impose from time to time) any hearing examiner or administrative law judge assigned to or employed thereby, shall have the power to hold hearings and issue subpoenas, administer oaths, examine witnesses, conduct examinations, and receive evidence at any place in the United States they respectively may designate.