(a) "Law-enforcement agency" means and is limited to:
(1) The state police and its members;
(2) A county sheriff and his or her law-enforcement deputies;
(3) A police department in any municipality as defined in section two, article one, chapter eight of this code; and
(4) Any federal agency whose purpose includes enforcement, maintenance and gathering of information of both criminal and civil records relating to domestic violence under federal law.
(b) The term "law-enforcement agency" includes, but is not limited to, the Department of Health and Human Resources in those instances of child abuse reported to the department that are not otherwise reported to any other law-enforcement agency.