This resulted in child abuse reporting laws that had been passed in the 1960s being amended to address the needs of child sexual abuse victims for identification, intervention, and protection. As the public’s awareness of the devastating impacts of childhood sexual abuse increased, reports of this abuse rose at an alarming rate. In 1976, confirmed cases of child sexual abuse represented only 3.2% of all child abuse reports; by 1982 these reports had increased to 6.9% of confirmed cases of child abuse (Russell & Trainor, 1984). The National Center on Child Abuse and Neglect (NCCAN, 1987) indicated that in 1986 there had been an estimated 2.25 million cases of child abuse reported and over 1.5 million cases confirmed that year alone, and that of those reported cases, the incidence of child sexual abuse was 2.5 children per 1,000 annually, or a tripling of reported incidence from 1976 to 1986. By 1993, child protection investigations had increased to nearly 3 million per year nationwide, but the reported rates of sexual abuse had remained stable and the demographics had not changed significantly (Snyder, Sickmund, & Poe-Yamagata, 1996). In all samples, juveniles have been the alleged perpetrators in at least 30% of reports of child sexual abuse (Finkelhor, 1996). The incidence rate of child sexual abuse confirmed by child protective services dropped to 2 per 1,000 children per year in 1994 (American Humane Association, 1996). Underreporting has continued to be a problem and a Gallup survey indicated that the true number might be as many as 19 per 1,000 per year (American Humane Association, 1996). However, most recently, evidence of a decline in reported child sexual abuse has been systematically reviewed, controlling for every conceived reason why such data might be unreliable, and it is apparent that there has been a decline over the past decade (Finkelhor & Jones, 2004).

Although numerous studies have revealed the magnitude of the problem, none have fully defined the incidence or prevalence of child sexual abuse because data is often limited to cases handled by child protective services agencies or counts only legally defined cases. Such data may not reflect the incidence of sexual abuse of children by older juveniles for several reasons. Many reports of juvenile offenses are rejected by social service intake criteria, which exclude nonfamilial cases. Extrafamilial or third-party cases are often referred to law enforcement or criminal justice, and we know that not all juvenile child sexual abuse involves sibling incest. The Uniform Data Collection System of the National Adolescent Perpetration Network reported 38.7% of cases involved siblings and 15% were crimes against peers or older individuals. The balance, 46.2%, were offenses against unrelated children; such cases, involving neighbors, friends, and acquaintances, are seldom investigated by social service systems. Although the Uniform Data Collection System’s sample (N = 1,600) contains an enormous amount of data on cases, it cannot contribute to our knowledge of incidence or prevalence because the data came from multiple treatment providers in many states, but not every provider in any one state. One area of information in that sample does, however, support the notion that all official data underreport the true incidence: the majority of the juveniles were being referred for charges of a ″first offense″ and yet the average number of victims identified was seven, suggesting many unreported offenses had already occurred (Ryan, 1988; Ryan, Miyoshi, Metzner, Krugman, & Fryer, 1996).