Researchers are currently seeking antecedents of psychopathy among children and adolescents. Instruments developed for this purpose are likely to be used in the future in ways that may have serious implications for youths in delinquency and criminal cases. In this regard, and because the concept and measurement of psychopathy have been developed in reference to adults, there is reason to be concerned about potential developmental sources of false positives when measuring psychopathic traits in juvenile offenders. We provide the basis for our concern, as well as standards regarding the types of research evidence that should be provided before psychopathy measures are accepted for use in juvenile forensic assessments.