Victims were overwhelmingly 'city' males age 15 and older, with homicide rates higher for nonwhite victims. The great majority of the victims were slain by solitary civilians of the same race, one fourth of whom were women. Those slain by LEP were younger, more often unmarried, and less likely to be under the influence of alcohol. Long-term temporal patterns were reflected in the changing rates of homicides in general. Rates of JH were compared and contrasted with those of culpable homicide (CH). Similarities were observed between JH and CH with respect to hour of day, day of week, and month of year. Most JH's by civilians occurred during or immediately following a quarrel. The majority of JH's by LEP were in self-defense when the victims were committing a crime of resisting arrest. The percent of JH in the overall homicide toll decreased throughout the 25-year interval. Inasmuch as JH by civilians remained a relatively constant fraction of all homicides until the final years of this study, the decline in percent of JH in the overall homicide toll largely reflects decreased JH by LEP. (Author abstract)