5 C.F.R. § 2411.11
(b) As used in this section, “unusual or exceptional circumstances” means, but only to the extent reasonably necessary to the proper processing of the particular request:
(c) Expedited processing of a request for records, or an appeal of a denial of a request for expedited processing, shall be provided when the requester demonstrates a compelling need for the information and in other cases as determined by the officer processing the request. A requester seeking expedited processing can demonstrate a compelling need by submitting a statement certified by the requester to be true and correct to the best of such person's knowledge and belief and that satisfies the statutory and regulatory definitions of compelling need. Requesters shall be notified within ten (10) calendar days after receipt of such a request whether expedited processing, or an appeal of a denial of a request for expedited processing, was granted. As used in this section, “compelling need” means: