Successes of law enforcement in apprehending offenders are often publicized events. Such events have been found to result in temporary reductions in oending, or "residual deterrence". We provide a theory of residual deterrence which accounts for the incentives of both enforcement ocials and potential oenders. Our theory rests on the costs of reallocating enforcement resources. In light of these costs, we study the determinants of offending such as the role of public information about enforcement and offending.