A model for teaching criminal justice ethics is presented that encompasses utilitarianism and contractarianism. A key feature of the model is that the investigation and judging of theories are interactive. In presenting the theories, the authors do not simply describe procedures that each theory offers for deciding how to act in ethically problematic situations. Rather, by addressing the issue of traits, the authors consider the kind of person each theory envisions. The model was applied in an upper-level undergraduate course on ethical issues in criminal justice. Almost all of the 35 students enrolled were criminal justice or philosophy majors. A few weeks were spent teaching the two rival theories. The roles of various criminal justice professionals were then investigated, along with the kinds of ethical problems they encounter. Students applied the model in small group sessions and discussed appropriate ethical options. The model's ultimate rationale is that criminal justice students will be better acquainted with what is right to do rather than to merely be able to articulate the correct theory concerning what is right to do. Appendixes contain a course syllabus for ethical issues in criminal justice, final exam questions, and paper assignment guidelines. 5 references