AbstractSuccesses of law enforcement in apprehending offenders are often publicized events. Such events have been found to result in temporary reductions in offending, or “residual deterrence”. We provide a theory of residual deterrence that accounts for the incentives of both enforcement officials and potential offenders. We do so by introducing to a standard inspection framework costs that must be incurred to commence enforcement. Such costs in practice include hiring specialized staff, undertaking targeted research and coordinating personnel. We illustrate how our model can be used to address a number of policy questions regarding the optimal design of enforcement authorities.