"Homicide is the second leading cause of death among persons aged 15–24 years in the United States (4). In some cities, such as Los Angeles and Long Beach, gang homicides account for the majority of homicides in this age group (61% and 69%, respectively). The differences observed in gang versus nongang homicide incidents with regard to victim demographics, place of injury, and the use of drive-by shootings and firearms are consistent with previous reports (5). The finding that gang homicides commonly were not precipitated by drug trade/use or other crimes in progress also is similar to previous research; however, this finding challenges public perceptions on gang homicides (5). The public often has viewed gangs, drug trade/ use, crime, and homicides as interconnected factors; however, studies have shown little connection between gang homicides and drug trade/use and crime (5). Gangs and gang members are involved in a variety of high-risk behaviors that sometimes include drug and crime involvement, but gang-related homicides usually are attributed to other circumstances (6). Newark was an exception by having a higher proportion of gang homicides being drug-related. A possible explanation of this divergent finding could be that Newark is experiencing homicides by gangs formed specifically for drug trade. Overall, these findings support a view of gang homicides as retaliatory violence. These incidents most often result when contentious gang members pass each other in public places and a conflict quickly escalates into homicide with the use of firearms and drive-by shootings."

Source

"Gang Homicides — Five U.S. Cities, 2003–2008," Morbidity and Mortality Weekly Report (Atlanta, GA: Centers for Disease Control, January 27, 2012) Vol. 61, No. 3, p. 48.