What is typically the first step in personnel security investigations?

The first step in personnel security investigations is the National Agency Check (NAC). This process is foundational and involves a thorough background check that includes a review of an individual's criminal history, credit history, and other records to assess their eligibility for access to classified information or sensitive positions. The NAC serves as a preliminary evaluation before more in-depth investigations are conducted.

The NAC is critical as it lays the groundwork for subsequent investigations such as the ANACI (Access National Agency Check with Inquiries), which is a more comprehensive check that includes inquiries into a candidate's background and character. The ENTNAC and SSBI (Single Scope Background Investigation) follow the NAC, but they are not the initial step. Each of these subsequent investigations builds upon the findings of the NAC, ensuring a thorough vetting process for personnel security.