 He focused on FBI records procedures, rather than individual FBI targets, leading to discoveries or further understandings of the complexities and uses of FBI office files (as opposed to "official" FBI files), the JUNE mail file, the National Security Electronic Surveillance Index Card File, Surreptitious Entries file, COMPIC file, and COMRAP file.His work has led some of his graduate students also to embark on FBI research.Two of his former PhD students include Kenneth O'Reilly (FBI and HUAC) and Christopher Gerard (FBI and the Senate Internal Security Subcommittee).