Backgrounding an individual commences with a thorough investigation of all documentary sources of intelligence on the subject. A covert, field surveillance should immediately follow 'paper backgrounding' to verify information collected and to develop new avenues of inquiry. Where appropriate, the investigation should terminate with 'overt' interviews with references and individuals affiliated with the subject. These three phases of inquiry ensure a comprehensive picture of the subject's character, activities, affiliations, and aids in verifying information that a subject may provide.