Homicide is a generic term referring to the killing of a person. It may be accidental or intentional. Accidental homicide is usually referred to as manslaughter. Murder is generally more narrowly defined as the unlawful killing of a person with “malice aforethought.” Homicide is a serious problem in the United States. Homicide rates are exceptionally high when compared to other developed nations. A distinguishing characteristic of homicide in the United States is place-to-place variation. Another sharp difference between the United States and its peers rests in attitudes toward gun control. There are temporal variations in murder, such as trauma medicine effectiveness. The American South has elevated homicide rates. Considerable controversy has centered on the role of culture in high southern homicide rates. Proponents claim that the South has different attitudes in matters such as defense of personal honor, levels of firearm ownership, and values tied to the prevalence of fundamentalist Christianity. In terms of age, the 18 to 24 age group is dominant for both offenders and victims of homicide. Homicide is a male crime, with 68 percent of murders having a male victim and offender. Victimization rates for African-American males are 10 times those of comparably aged white males, although rates have fallen in recent years. Homicides are most often committed by guns, especially handguns. The use of guns in homicides varies regionally. Homicides tend to manifest as hot spots with remarkably high rates of occurrence in small areas, accompanied by steep gradients of decline with distance from those hot spots. Urban poverty is the central explanatory fact of the geography of American homicide. 5 figures, 6 references