Four steps in background investigation are discussed: taking a personal history statement (PHS) from the applicant, evaluating the PHS, consulting files open to the investigator, and making a field investigation. In addition, requirements for the following PHS components are reviewed: facts to confirm identity, personal history, residence history, educational history, references, employment history including military service, financial history, criminal involvement, credit record, and availability. For example, residence history should be complete chronologically and should go back at least 15 years. Evaluators of a PHS are advised to be wary of post office box numbers that are used as addresses, 'dead ends' or unverifiable bits of information, inconsistencies, and ellipses. The article also describes the kinds of information that investigators can obtain from such sources as credit and motor vehicle bureaus, central and special registries, business and local newspapers, and directories; problems posed by sealed, inaccurate, or incomplete records; specific investigative techniques (such as character references in person); and techniques for conducting a personal interview (positive vetting) based on the PHS. U.S. guidelines defining fair employment policies are included.