Recently, some researchers have developed new ways of understanding the relationship between suicide and homicide which are conceptualized as different expressions of the same phenomenon or results of the same underlying social forces, specifically social deprivation. However, there are differing opinions on how suicide and/or homicide become the result of social deprivation. Three hypotheses are presented as explanations on this issue and then tested: (1) attribution hypothesis--takes the causes of attribution for granted without explaining what generates blame-worthiness toward self or others; (2) socialization hypothesis--assumes that individuals who are subject to the regulation of workplace and schools are more likely to contain their impulses than others and reduces people’s involvement in homicides but increases their chance of committing suicide; and (3) social disorder hypothesis--states that both suicide and homicide are reflections of social disorder which is considered vague. Utilizing data on both suicide and homicide from the Multiple Cause of Death study, a 3-year (1989-1991) study on the average suicide rate and average homicide rate, as well as data from vital statistics and census data, this study tested each hypothesis. The analysis suggests that both suicide and homicide rates may result from the same underlying causes, which is a principle of the social disorder hypothesis. However, when three sets of indicators of the tested hypotheses were separately entered in the equation, consistent support was found only for the attribution hypothesis. In conclusion, among the three competing explanations of lethal violence, the attribution hypothesis possessed the most convincing evidence. How lethal violence is expressed is contingent upon the direction of attribution. The results suggest that it is fruitful to examine both suicide and homicide under the same theoretical and empirical framework. References