In this article, the author reviewed theory and research on the relationship between mental illness, crime, and violence. The author began by discussing the larger backdrop of deinstitutionalization of mental illness and its consequences for the criminal justice system in both individual and macro-level terms. The author then compared public perceptions of dangerousness associated with mental illness with individual-level studies that assess the risk of violence and criminal behavior among those with mental illness. He reviewed key findings as to the role of certain psychotic symptoms, social demographic characteristics, and the context in which violence unfolds. Finally, the author discussed recent efforts at managing persons with mental illness who violate the law, focusing on the limitations of diversionary programs. (Published Abstract)