The basic data are the National Center for health statistics' annual tabulations of decedents by age, sex, color and cause of death. Data analysis shows that homicide is mnuch more common in the black community than in the white community--age-standardized homicide rates are currrently about six times as great for nonwhites as for whites. For both races, the age-standardized homicide rate for men is about four times than for women. Homicide rates are highest at ages 25 to 35 and generally decline thereafter, establishing homicide as the leading cause of deaths among nonwhites, and the second most frequent cause of mortality for white men at the young adult ages. For both men and women, homicide death rates have risen very rapidly since the mid-1960's . Two popular but competing models try to explain the rise in homicides. The deterrence model argues that the rise is related to the elimination of capital punishment in many states, the social structure model counters that a number of variables--poverty, overcrowding, unemployment, discrimination--are to blame for the increase. However, these models overlook an important technological change: the increasing availability of firearms. If firearms were not at hand, the murder rate would probably drop sharply because combatants would often use less lethal weapons. However, data from the National Commission on the Causes and Prevention of Violence indicate that a decrease in gun ownership is improbable. Tabular data and approximately 30 references are given.