The General Accounting Office (GAO) selected six agencies for review in this study: the Drug Enforcement Administration (DEA), the Federal Bureau of Investigation (FBI), the Former Immigration and Naturalization Service (INS), the U.S. Marshals Service, the former U.S. Customs Service, and the U.S Postal Inspection Service (USPIS). To identify the guidance and procedures followed by Federal law enforcement agencies regarding counting and reporting investigation and arrest statistics, the study reviewed agency mission statements, policies, and applicable manuals concerning investigations and arrests. The study also obtained information about the agency investigations and arrest statistical tracking systems. The study produced an Administration Profile for each of the six agencies reviewed under this examination. To determine if multiple agencies were reporting the same investigations and arrests, information from agencies’ statistical systems was analyzed. The study found that guidance and procedures for counting investigations were generally consistent among the six agencies GAO reviewed. Agencies pursue investigations into crimes that have a nexus to their missions. Once agents have made a decision to open a case, the cases are to be reviewed and approved by a supervisor, and details of the case are then entered into the agencies’ case management and tracking systems. GAO also found agency guidance and procedures for counting arrests to be generally consistent among all six agencies. In addition, the agencies required a supervisory review of the justifications for the arrests before they were entered into the agencies’ data tracking systems and officially counted. The Departments of Justice and Homeland Security and USPIS reviewed this study and generally agreed with the GAO’s findings. 11 Figures