Federal law enforcement components used more than 16,000 confidential informants in fiscal year 2013 as part of criminal investigations. Informants can be critical to an investigation, but without appropriate oversight, problems can occur that undermine the credibility of the informant's role in an investigation. The Attorney General's Guidelines sets forth procedures on the management of informants, including vetting potential informants and overseeing informants' illegal activities that components authorise to support an investigation. This book reviews the extent to which the Department of Justice (DOJ) and the Department of Homeland Security (DHS) components' policies address the Guidelines for vetting informants and overseeing their illegal activities; and selected components have monitoring processes to ensure compliance with the Guidelines.