Training tools and subject-matter for teaching ethics to law enforcement personnel were examined. A literature review revealed seven categories of training tools including: (a) books and publications, (b) case studies of ethical dilemmas, (c) codes of ethics, (d) decision-making processes, (e) films, (f) philosophies and philosophers, and (g) whistle-blowing (reporting the misconduct of others). Determining the most useful training tool for maintaining proper behavior and improving recalcitrant behavior is an important step in developing effective law enforcement training. In the summer of 2005, a multimethod survey examined the preferences of three populations. The populations were in-service police officers from Phoenix, Arizona, retired police officers from Phoenix, Arizona, and a nationwide group of ethics instructors. Respondents were asked to identify the ethics training tool believed to be most useful for law enforcement training towards maintaining proper behavior and improving recalcitrant behavior. The research found that all three populations chose case studies more frequently than any of the other six tools.