The authors trace changes in the criminal justice system approach and ideology concerning cases in which child sexual abuse is alleged. The chapter is divided into five sections. The first section discusses the way in which the criminal justice system prosecuted child sexual abuse and rape prior to the 20th century. This brief discussion focuses on legislation and court actions concerning forcible rape prosecution that occurred in Greek and Roman times, in England, and finally in the United States. The second section explores 20th-century professional writings on the subject of child sexual abuse and rape. The authors analyze psychological, sociological, psychiatric, medical, and legal writings in order to provide insight into the intellectual and social context in which the criminal justice system operated during this time. The third section describes child sexual abuse prosecution from the early 1900’s to 1950, concentrating on their study of 463 State appellate court decisions in criminal child sexual abuse cases from this time period. The fourth section explores the changes that occurred from around 1980 to the present, focusing on the many reforms that occurred during this time to facilitate prosecution and accommodate child victims in court. Also included in this section is a discussion of the use of expert testimony from mental health professionals. Finally, in the fifth section, the authors offer their conclusions, noting that those who prosecute offenders of child sexual abuse in the 21st-century have an easier time because of the tremendous strides made by 20th century pioneers. References