Homicide: Behavioral Aspects

While comparative studies have focused on the broad question of rates of homicide, studies in the United States examine how the rates change through time, which groups are affected, and the relationships between victims and offenders. Zahn and McCall summarize national homicide trends in the twentieth century. While national data from the early twentieth century are not readily available, they conclude that the homicide rate increased moderately between 1900 and 1933. After the mid-1930s, when data are more reliable, rates dipped sharply then rose between 1933 and 1974. The rates declined through 1964, although this decline was briefly interrupted by a short increase in the three years after World War II. After 1964, the rates began to rise from 6.1 per 100,000 in 1967 (UCR), to 9.7 in 1974, to an all-time high of 10.2 in 1980. Overall, the United States homicide rate doubled from the mid 1950s to 1980. After 1980, the homicide trend fluctuated, dropping to 7.9 in 1985, going up to 9.8 in 1991, and then decreasing through the late 1990s. In 1998, the UCR reported a homicide rate for the United States of 6.3, which represents the lowest U.S. homicide rate since 1967. In general, the highest homicide rates of the twentieth century in the United States occurred during the 1970s, 1980s, and early to mid-1990s, whereas the lowest rates occurred during the late 1950s.

There are consistent differences in rates of homicide victimization between males and females, blacks and whites, and young and old. In terms of age difference, homicide victimization rates are generally higher for young adults, especially young adult males. In the past, the highest rates have occurred for the age group twenty-five to thirty-four, followed by fifteen to twenty-four year olds. In the 1990s, the rates for most age groups declined, but the rates for these two groups continued to increase. By 1989, the fifteen to twenty-four-year-old group converged with and then surpassed the twenty-five to thirty-four-year-old group. In 1993, the homicide rate for fifteen to twenty-four year olds was 23.5 per 100,000 (Vital Statistics) and 19.5 for the twenty-five to thirty-four year olds. Zahn and McCall, who summarized these trends, point out that shift in the age structure of homicide is one of the most important changes in the patterns of homicide during the twentieth century.

Reynolds Farley has reported that ageadjusted homicide rates during the period 1940–1977 were about six times greater for men than for women. Race and gender-specific victimization rates from vital statistics from 1968 to 1997 confirm this, with a black male rate of 47 per 100,000 in 1997, compared to 6.7 per 100,000 for white males. (The rate for black females in that year was 9.3 and for white females 2.3.) Explanations for why racial minorities are overrepresented as both victims and offenders of homicide have focused on income inequality between racial groups as well as racial segregation in housing. Segregation into areas with few economic resources may lead to frustration and hostility that increase violence. Such isolation may also undermine the ability of the community to mobilize community residents for crime prevention activities (Peterson and Krivo).

The low rates of victimization and offending for women as compared to men are not adequately explained. Differences in social inequality do not seem to be as important, and various studies have confirmed that there has not been a great escalation of female homicide rates accompanying women's increased participation in the labor force in the United States. While males dominate as victims and offenders when considering the homicide rate overall, gender patterns differ greatly in reference to a specific type of homicide, intimate partner homicide. Only in the area of partner homicides do women's offending rates approach that of men; even here, however, women are twice as likely to be killed by their partners as men are by their female partners. Women are more likely to be killed by their male partners than by any other assailant. A substantial majority of homicides committed by women occur in response to male aggression and threat. Other studies show a history of physical abuse and threat by men who eventually kill their victims. It is clear that the link between partner separation and murder is more than incidental, such that when a woman leaves a man he experiences rage that leads to her murder. A summary of research on homicide between intimate partners is found in Browne, Williams, and Dutton.