The Marine Corps Intelligence Activity (MCIA) is the Intelligence Support and Coordination Center for the Marine Corps Intelligence, Surveillance and Reconnaissance Enterprise. MCIA produces all-source intelligence, provides intelligence services, and conducts intelligence and counterintelligence operations in support of current and future operations and force development. MCIA's intelligence operations center is the Marine Corps' 24/7 single point of access for all-source intelligence reach-back support. MCIA is comprised of the service intelligence center, CI/HUMINT Support Company and the Marine Cryptologic Support Battalion (MCSB).
(From: http://www.hqmc.marines.mil/intelligence/Units/MCIA/)
MCRP 2-10A.2 Counterintelligence (Formerly MCWP 2-6) by 
MCWP 2-14 - Counterintelligence by 
A Study of United States Marine Corps Counterintelligence and Criminal Investigative Organization by 