types of clearance investigations
Security Clearance Background Investigations for the Department of Defense (DOD) are conducted by the Defense Security Service (DSS). This includes background investigations for military personnel, civilian personnel who work for DOD, and military contractors. The Office of Personnel Management (OPM) conducts Security Clearance Investigations for most other branches of the Federal Government.
The elements that make up a background investigation vary depending on the level of clearance that is deemed necessary for a position. Background investigations for lower levels of security clearances generally rely on automated checks of an individual's history.