This research project, currently co-sponsored by the Promise Institute for Human Rights, studies how and why states have been pursuing the transnational prosecution of crimes against humanity, genocide, torture and war crimes across the world. Professor Máximo Langer created and regularly updates with the support of other researchers and research assistants a database on the transnational prosecution of these crimes based on the principle of universal jurisdiction. Products of this project include “The Quiet Expansion of Universal Jurisdiction” in the European Journal of International Law and Migration and the Demand for Transnational Justice in the American Political Science Review.