This paper is aimed at criminologists and criminal justicians seeking to understand their role in educating law enforcement and correctional personnel who must deal with the mentally ill. It is motivated by William Johnson's (2011) recent call for rethinking the interface between mental illness, criminal justice, and academia, and his call for advocacy. We concur with his concerns, and insist that this rethinking must necessarily include grounding in the etiology of mental illness (specifically, with schizophrenia) as it is currently understood by researchers in the area. Advocacy must go hand in hand with a thorough knowledge of the condition of the people for whom we are advocating. We first examine major etiological models of schizophrenia, emphasizing the neurodevelopmental model that incorporates genetics, neurological functioning, and immunological factors guided by the assumption that the typical criminologist/criminal justician has minimal acquaintance with such material. We then address the link between schizophrenia and criminal behavior, and conclude with a discussion of the implications for criminology and criminal justice.