Sexual crimes against children appeared before the courts with a dramatically increasing frequency over the course of the nineteenth century. But these prosecutions did not always translate into successful convictions of sexual offenders, in part due to contradictory and ambivalent understandings of childhood innocence and doctors’ frequent negative findings concerning the physical traces of these crimes. Medicolegal experts routinely cast moral judgements on the children, particularly working-class girls, identified as victims of sexual crimes. Influenced by bourgeois attitudes toward male honor and notions about the perceived immorality of the working class, these doctors warned that children’s accounts of sexual assault could not be trusted and could destroy men’s reputations. By discounting children’s accounts, doctors laid claim to their exclusive ability to evaluate proof of sexual offenses against children. Furthermore, by discrediting children identified as victims of sexual crimes, medical practitioners shaped attitudes toward sexual assault that presented long-lasting challenges to the pursuit of justice.