Particular topics discussed are the national prevalence of gang homicide; changes in the prevalence and in the proportion of all homicides that are gang related in the cities for which these data are available; and comparisons of characteristics of gang homicides with other homicides, using data from several areas within Los Angeles County and deciphering whether these patterns have changed during the last 15 years. These discussions are preceded by a review of some methodological issues that affect efforts to better understand the scope and nature of gang homicide. The studies of the nature of gang homicides in several large but otherwise diverse U.S. cities found that such homicides most often reflect the dynamics of gang membership, such as continuing intergroup rivalries, neighborhood turf battles, identity challenges, and occasional intragroup status threats. The victims in gang homicides are usually other gang members. There is no indication that gang homicides are embedded in drug distribution systemic processes or random acts of expressive outrage against innocent citizens. The increase in gang homicides in the face of the current declining trend in other types of homicide suggests that the unique aspects of gang violence deserve greater and specialized attention. 2 figures, 5 tables, and 55 references