Sexual serial homicidal behavior has received considerable attention during the last three decades. Substantial progress has been made in the development of methods aimed at identifying and apprehending individuals who exhibit these behaviors. In spite of these advances, the origins of sexual serial killing behavior remain for the most part unknown. In this article we propose a biopsychosocial psychiatric model for understanding the origins of sexual serial homicidal behavior from both neuropsychiatric and developmental perspectives, using the case of convicted serial killer Jeffrey Dahmer as the focal point. We propose that his homicidal behavior was intrinsically associated with autistic spectrum psychopathology, specifically Asperger's disorder. The relationship of Asperger's disorder to other psychopathology and to his homicidal behavior is explored. We discuss potential implications of the proposed model for the future study of the causes of sexual serial homicidal crime.