"Most of the empirical research and practically all of the fieldwork conducted on gangs has been devoted to street gangs. In this paper, automated data from the Bureau of Prisons were used to evaluate the contribution of prison gang affiliation to violent and other forms of misconduct within the institution. We also examined a measure of gang embeddedness to see if, similar to the street gang research, it can be shown that core members of a prison gang were more likely to commit violent and other kinds of misconduct than more peripheral members. A composite measure of gang misconduct is also presented to represent the threat that a particular gang poses to prison order. The 'threat index' is model-based and provides a graphical representation of the relative magnitude and heterogeneity of threat posed by different gang affiliations."