Managing a Confidential Informant (CI) is one of the most effective tools in modern law enforcement. It is also one of the most legally dangerous. In the United States, informant management is not governed by a single act of Congress. Instead, handlers must master a complex patchwork of Constitutional Case Law, Federal Administrative Guidelines, and State-Specific Statutes. Violating these rules can compromise an active investigation, lead to the dismissal of criminal charges, or result in federal civil rights lawsuits against the handler. Here is the essential legal framework every handler, investigator, and agency supervisor must master.