Interviews were conducted in correctional environments and at a university location to obtain information from both confined gang members and gang members at large. The interviews were structured to examine the impact of the GD prosecution on the structure and function of the GD gang. Data from the interviews and materials written by the GD leader served to characterize the rules, regulations, and codes of the GD organization; the importance of organizational development and education; political activities of the GD; methods used to keep gang members in line; and violent activities of the GD. In 1993, the Federal Government's Operation HEADACHE, the official codename for the GD investigation, was in full swing. The GD leader and 38 of his top associates were indicted in 1995 on charges of conspiracy to distribute cocaine, crack, heroin, and marijuana and to extort protection money from street dealers in Chicago. The GD leader was convicted in 1997. The projected long-term impacts of the GD prosecution included membership demoralization, organizational destabilization, collateral impact, deterrent effect, and restored public confidence in law enforcement. Other gangs, however, may have benefited from the GD prosecution due to the displacement effect. The author concludes that the rise and decline of the GD is a case study in organizational dynamics for a criminal enterprise. An appendix lists printed materials of the GD gang. 23 figures