A theoretically integrated model used homicide rates disaggregated by the victim/offender relationship and the precipitating incident for a sample of American cities in 1980-84. The findings revealed significant evidence of differential effects. All of the indicators except regional location had significant effects on the total homicide rate, but estimation using the disaggregated rates showed that some of the indicators had rather extensive effects (e.g., percent poor and divorce rate), and the effects of others (e.g., justifiable-homicide ratio and population density) were more limited. Although the effects of the indicators varied, that variation was not random. Rather, the patterns observed were theoretically expected. The conclusion from the findings should not be that the total homicide rate is meaningless and should be discontinued. It is useful for determining general homicide patterns; however, finding a significant effect for the total homicide rate does not necessarily mean that the variable is causally relevant for all forms of homicide. Disaggregated rates must be analyzed to determine this. 3 tables, 35 references.