Section 57.3 - Scope and purpose of investigation; other sources of information(a) The authority granted the Attorney General by section 816(d)(1) of the Act (e.g., authority to inspect books and records) shall not be utilized until an appropriate official has defined, in an appropriate internal memorandum, the scope and purpose of the particular investigation.(b) There shall be no use, with respect to particular information, of the authority granted by section 816(d)(1) of the Act until an appropriate official has determined that the information in question is not available to the Department of Justice from any other Federal agency or other responsible agency (e.g., a State agency).(c) For purposes of this section, "appropriate official" means the Assistant Attorney General in charge of the division conducting the investigation, or his delegate.