In the last 30 years, prosecutions of public corruption cases have continued to increase in the United States. Some cases are short-term acts, such as a bribe for a contract, but others are long-term and systematic, such as the Pennsylvania judges’ kids for cash scandal. This project involved interviews with 73 former investigators, prosecutors, community stakeholders, and individuals with first-hand experience in corrupt activities, together with analysis of court documents, to reveal how such cases came to the attention of law enforcement. Information about corrupt acts comes to law enforcement in a few distinct ways: experienced by a member of the community, discovered during other investigations, tips from anonymous persons or whistleblowers, and through regularly required audits. Empirical examples from interviews and court cases show how law enforcement identified corrupt acts. Unlike business fraud, whistleblowers appear to play a smaller role compared to informants and other criminals in corruption cases.