• International Association of Penal Law
  • American Society of Comparative Law, Director (Saint Louis University) 2000-2016
  • Associate Member, International Academy of Comparative Law, since 2010
  • Editorial Advisory Board: Journal “Ultima Ratio” published by Instituto Panamericano de Politica Criminal, São Paulo, Brazil since 2005
  • Editorial Advisory Board: Palestra, of the National Bar of Poland. Since 2014.
    Scientific Advisory Board, Max-Planck Institute for Foreign and International Criminal Law, 2008-2014.
  • Co-Chair, American Bar Association’s Missouri Death Penalty Assessment Team.Conducting study of the implementation of the death penalty in Missouri to see if the state complies with ABA guidelines for death penalty practice. 2009-2012. Report published in March 2012.
  • Member of Advisory Board. Istanbul International Crime and Punishment Film Festival. (2011-present)
  • Member of Monitoring Unit: Criminal Law and Criminal Sciences Research Centre. Institute of Criminal Law and Criminal Sciences. University of Lisbon, Portugal. Since June, 2013.
  • Member, Board of Directors, International Association of Penal Law: 2014-2024
    Vice-President, International Association of Penal Law: Since 2024
  • Scientific Committee of Journal: Processo penale e giustizia, Italy, Since 2017