This monograph addresses the role of criminal non-state actors in South America. In a departure from traditional analysis, the author notes that non-state actors that affect political and social life in the Global South are not always terrorist actors or the result of political disputes. In several countries, criminal actors with a high degree of complexity emerge, capable of performing violent actions that proportionally surpass the economy of crime. Furthermore, they are capable of carrying out actions beyond the state, in a transnational approach, connecting with criminal organizations in other countries and or even other violent non-state actors. This volume consolidates studies on criminal non-state actors in South America, analyzing their historical development, governance capacity, profiling key actors, and assessing their overall effect on international relations as a whole. As such, it will be useful to students and researchers interested in international security, criminology, Latin American studies, and peace and conflict studies.