The Defense Personnel and Security Research Center (PERSEREC) identified Federal Bureau of Investigation (FBI) tools and datasets that can assist with the identification of domestic terror (DT) and domestic extremist (DE) ideological indicators and group membership during the accessions and personnel security vetting processes. To accurately identify appropriate FBI resources, PERSEREC examined DE groups and ideologies, mapped the military accession screening and personnel security vetting processes, and interviewed FBI personnel to better understand available capabilities. PERSEREC found several examples of extremists who were active or former military Service members, and identified FBI capabilities, as well as others that could be integrated into the military accessions screening process and the personnel security program.