The mission of the FBI is to protect and defend the United States against terrorist and foreign intelligence threats, to uphold and enforce the criminal laws of the United States, and to provide leadership and criminal justice services to federal, state, municipal and international agencies and partners. This book details what an FBI record is, what researchers can learn from these records, and how they can be used. The FBI has long been of interest to researchers, given the importance and scope of its mission and the range of historical events that is has been involved in over the years.