Page 6 of 42 103 Minn. L. Rev. 844, *852 follow from determinations that there is insufficient evidence to support charging, and common law jurisdictions [*853] have long left those assessments in the unregulated discretion of police and prosecutors. 77 But that is not the whole story. For one, it does not follow from the fact that officials must assess evidentiary sufficiency that their assessments should be unregulated or unsupervised. The tradition in civil law jurisdictions is otherwise, and available evidence often depends on the effort and priority officials give to finding it. More importantly, how rigorously we guard against unmerited nonenforcement depends on how we value the interests harmed by nonenforcement, and on how much we worry about nonenforcement for the wrong reasons. Both have changed over time. The primary causes of underenforcement are failing to investigate and charge due to biases against certain victims or harms, or favoritism toward certain kinds of suspects. 7° Three kinds of crimes - local government corruption, sexual assaults, and unjustified uses of force by law enforcement officers - illustrate the link between these risks, failures to enforce, and the consequences of underenforcement. Local corruption garners the least public and political attention now; 7° not coincidentally, the United States has found an effective model of enforcement redundancy on this front. 7° The justice system's responses to sexual assault and police violence, on the other hand, are subjects of heated political and policy debates. 7! There has been notable progress in reducing the criminal justice system's disregard of [*854] both kinds of offenses, but underenforcement - and almost as important, widespread suspicion of underenforcement - remain significant enough that they illustrate some of the key costs of those failures. Suspicion of underenforcement is itself a cost, because it reflects a loss of legitimacy for criminal justice institutions. That loss