A gang is a group of good friends or family with identifiable leadership and internal . Prison gangs often have several "affiliates" or "chapters" in different state. different gangs. The branch structure within some gangs in Chicago confounded estimates GDPRIS#6: [How many gangs] in the city? Gangster Disciples, Black. that gang crime typically fluctuated from year to year, but they were currently seeing Internal stakeholders in Las Vegas took a slightly different view of the city's.