Better understanding, openness, and trust among black and white police officers would increase police effectiveness in dealing with police-community relations. This study discusses a program to improve black-white police relations through role playing techniques and small group interactions on problems of human relationships. Longitudinal in design, the study assesses: (1) changes in values and attitudes over time; (2) optimal implementation time for the training program; (3) effectiveness of the program; and (4) the attitudinal effect on officers of precinct assignments and inter-racial contact. Some positive changes took place in the attitudes of black officers participating in the program during academy training. Negative attitude changes occurred in white participants and spread to white non-participants. A similar program conducted a year later avoided the severe backlash effect by downplaying its racially-motivated aspects. It, too, failed to improve black-white relations in any significant way. It appears that polarization between black and white officers begins upon entrance to the police academy, although a training program can sensitize each group to the other. Precinct assignment has little impact on values but strong impact on attitudes development, with duty in white precincts fostering undesirable viewpoints about blacks among both black and white officers. The study suggests that rotating precinct assignments for all officers would be a helpful step in combating stereotypic racial attitudes among all police. (Author/NMF)