Data came from a police database and police files. The research examined the association between gang activity and narcotic use and trafficking among all homicides during 1986-88. In addition, detailed data from police files were used to examine the same associations for a subset of homicides in south central Los Angeles. The research also examined the association between gang homicide victimization and the victim's cocaine use for all Los Angeles homicides in 1987. The study also compared narcotics arrest histories for gang homicide victims with histories for other homicide victims. Results revealed that gang-motivated homicides were less likely than other homicides to involve narcotics; narcotics-motivated homicides were less likely to involve a gang member than were other homicides. In addition, victims of gang-motivated homicides in 1987 were less likely than other homicide victims to have detectable levels of blood cocaine. Finally, young victims of gang-involved homicide were no more likely than other victims to have a history of narcotics arrests. Findings did not support the theory that a substantial proportion of homicides are attributable to gang involvement in narcotics trafficking. Tables and reference notes (Author abstract modified)