Previous research showing that income inequality (assessed by the Gini index) is a predictor and hence a possible determinant of homicide rates, whether at the cross-national, State, or city level, has been inconclusive because of a negative relationship between economic inequity and average income. Comparison across the Canadian provinces provided a test case in which average income and the Gini were positively correlated, and the positive relationship between the Gini and the homicide rate was undiminished. In addition, temporal change in the Gini is a significant predictor of temporal change in provincial homicide rates. When Canadian provinces and U.S. States were considered together, local levels of income inequality appeared to be sufficient to account for the two countries' radically different national homicide rates. The paper concludes that the degree to which resources were unequally distributed was a stronger determinant of levels of lethal violence in modern nation states than was the average level of material welfare. Figures, tables, note, references