28 C.F.R. § 549.90 – Purpose and application.

(a) This subpart provides definitions and standards for review of persons for certification to federal district courts as sexually dangerous persons, as authorized by title 18 U.S.C. Chapter 313, by Bureau of Prisons staff or contractors (collectively referred to in this Part as “the Bureau”).
(b) This subpart applies to persons in Bureau custody, including those:
1. (1) Under a term of imprisonment;
2. (2) For whom all criminal charges have been dismissed solely for reasons relating to the person's mental condition; or
3. (3) In Bureau custody pursuant to 18 U.S.C. 4241(d).
(c) The Bureau may certify that a person in Bureau custody is a sexually dangerous person when review under this subpart provides reasonable cause to believe that the person is a sexually dangerous person. In determining whether a person is a sexually dangerous person and should be so certified, the Bureau will consider any available information in its possession and may transfer the person to a suitable facility for psychological examination in order to obtain information for this purpose.