This study focuses on street gangs in Chicago that have been present in poor Black and Hispanic urban communities for over fifty years. The study provides a contextualised summary of the main groups in which children and youth are involved in organised armed violence and also takes a closer look at the human face of this phenomenon, with profiles of individuals involved. Among the key findings of the study are that, unlike New York and other large US cities, gangs have “institutionalised” in Chicago over the years, providing their members with a highly organised structure and commanding a sense of loyalty.