Posthumous diagnoses are not uncommonly given to notorious public and historical figures by applying retrospectively, and typically in the absence of the individual being diagnosed, contemporary diagnostic criteria. Although this may be relatively easy and free of consequences when it concerns clear-cut medical conditions, it may have unintended repercussions in the case of psychiatric disorders by creating myths and perpetuating stigma. The case of serial killer Jeffrey Dahmer is a typical example where a somewhat facile and almost syllogistic application of perhaps over-inclusive criteria may have contributed to the legend of solitary murderers as possibly suffering from an autism spectrum condition. Although there may be an understandable human need to explain abominable and heinous behaviors, the lack of the possibility to verify a diagnostic theory and the ill-advised attempt to make a diagnosis fit may de facto be the basis of prejudice and profiling that do not correspond to clinical reality. Although there is no doubt that the brain is the organ of behavior, the authors caution against a budding neo-Lombrosian approach to crime and criminality and against the all too common use of widely differing terms in the study of deviance, such as crime, delinquency, and aggression, the operational use of which, often used interchangeably even in association studies, often erroneously leads to further confusion.