Regarding the classification of juvenile sex offenders, the optimal method has yet to be developed. As the literature suggests, developmental and clinical factors are added complications. Sexual development is still evolving in adolescence. In the case of paraphilias and deviant sexual arousal, the offender's age apparently correlates with the type of paraphilia, with noncontact sexual disorders such as transvestism, fetishism, and voyeurism emerging in early adolescence. The assessment of these disorders is especially difficult among juveniles, since younger subjects have greater variance in deviant sexual arousal patterns than adult sex offenders. Sexually deviant arousal and its link with sexual offending have rarely been studied in juveniles. Although there is little research on major mental illness associated with juveniles' sexual offending, the studies that do exist indicate a high prevalence of comorbid mental disorders among sexually aggressive juveniles. Some preliminary research findings indicate that juvenile sex offenders have higher scores on measures of callous-unemotional personality traits (psychopathy) when compared with violent nonsexual offenders and nonviolent offenders. There is a need for research on the relationship between psychopathy and other personality styles associated with juvenile sexual offending. Overall, the identification of distinctive characteristics of juvenile sex offenders is complex because of significant differences within diagnostic subgroups. The task is further complicated by variation in the symptoms, prevalence, and etiology of childhood disorders depending on demographic characteristics such as gender, culture, and socioeconomic status. 51 references