Acts of public corruption can undermine the rule of law and the legitimacy of the state. Holding public officials to the rule of law through the threat of prosecution is a crucial mechanism to give the law meaning in practice. In the United States, nearly all prosecutions for public corruption occur at the federal level, although many defendants in these cases are officials at the state and local levels of government. When corruption cases are brought, they usually result in a conviction via a guilty plea. However, making these cases is difficult, with only about a third of investigations resulting in actual criminal prosecutions, an outcome much different from those seen in white collar or organized crime cases. In this study, we seek to elicit the decision-making processes that occur in corruption investigation and prosecution. On the basis of 40 interviews with former investigators and former prosecutors, it has been found that experience, access, resources, and institutional barriers are all challenges to successful investigations. At the prosecution stage, prosecutors face a somewhat different set of barriers, including implied legitimacy concerns, thresholds, and potential long-term repercussions. Implications of these findings for policy and resources are discussed.