This discussion paper provides an overview of the linkages and challenges related to development support to transitional justice and specifically, the development of national capacity to try serious international crimes in line with the principle of complementarity. It highlights UNDP's added value in engaging on these issues based on the 2011 “UNDP Dialogue on Complementarity and Transitional Justice”, international best practices and UNDP global, regional and country experience on strengthening the rule of law, justice and accountability mechanisms in the context of human development. This paper also provides policy options to help practitioners and specialists better integrate transitional justice and complementarity into broader rule of law and development programming.