This chapter discusses major empirical data and studies on the prevalence of sexual assault and treatment for sex offenders and includes a discussion about issues associated with special sex offender populations. The Bureau of Justice Statistics (BJS) suggests that sexual assault includes a wide range of victimizations, separate from rape, or attempted rape. The feminist movements of the 1970s gave public voice to issues of adult sexual and domestic violence. The victim-offender relationship has been shown to be a key factor for violence, apart from depressive symptomatology and other pervasive mental health disorders, such as posttraumatic stress disorder (PTSD), substance abuse, fearfulness, and other somatic complaints. Sexual assault victimization has numerous costs and consequences for the victim, the offender, their families, and society at large. Criminal justice costs of sexual violence include those incurred for law enforcement, court proceedings, personnel, public education, and incarceration of convicted offenders.