The data and research reviewed provide examples of how future research on homicide might examine more thoroughly the nature and causes of ethnic, racial, and social class differences. The author advises that beyond the mere documentation of behavioral differences across a wider array of groups, the disaggregation of homicide data for racial and ethnic groups has important implications for the construction and testing of theory, especially those theories that have arisen in response to black-white comparisons in the past; for example, various theories (largely untested) have long held that black-white differences in crime, violence, and other social behaviors can be attributed to differences in socioeconomic status, cultural values, patterns of socialization, family life, levels of discrimination and oppression, place of residence, etc., The inclusion of multiple ethnic and racial groups in data analysis will allow researchers to determine the extent to which these and other factors may or may not account for homicide rates found among whites and various non-white groups. Further, although relatively uncommon in the homicide literature, longitudinal and historical analyses of homicide may offer the best test of the validity of competing explanations for group differences. In explaining racial and ethnic differences in homicide rates, one section in this chapter considers the utility of within-group comparisons, the effects of place, and the effects of social class. Another section addresses the benefits of a county-level analysis of homicide among racial and ethnic groups. 9 tables, 6 notes, and 66 references