Now retired, Nico Keijzer has taught criminal law at Vrije Universiteit, Amsterdam and at the Universiteit van Tilburg, and has served as a judge in the Supreme Court of the Netherlands. Elies van Sliedregt is Professor of Criminal Law including International Criminal Law at Vrije Universiteit, Amsterdam. In the past she has served on the defence team before the International Criminal Tribunal for the former Yugoslavia and the International Criminal Tribunal for Rwanda.