Analysts have long noted that some societies have much higher rates of criminal violence than others. They have also observed that the risk of being a victim or a perpetrator of violent crime varies considerably from one individual to another. In societies with ethnically and racially diverse populations, some ethnic and racial groups have been reported to have higher rates of violent offending and victimization than other groups. This series of essays explores the extent and causes of racial and ethnic differences in violent crime in the United States and several other contemporary societies.