Smeulers, A. (2023). Perpetrators of mass atrocities: terribly and terrifyingly normal? New York: Routledge.

The 9/11 attacks, as well as the ones in Madrid, London, Paris and Brussels; the genocides in Nazi Germany, Rwanda and Cambodia; the torture in dictatorial regimes; the wars in former Yugoslavia, Syria and Iraq and currently in Ukraine; the sexual violence during periods of conflict, all make us wonder: why would anyone do something like that? Who are these people? Drawing on 30 years of research, in this book Alette Smeulers explores the perpetrators of mass atrocities such as war crimes, crimes against humanity, genocide and terrorism. Examining questions of why people kill and torture and how mass atrocities can be explained, Smeulers presents a typology of perpetrators, with different ranks, roles and motives.

Devoting one chapter to each type of perpetrator, the book combines insights from academic research with illustrative case studies of well-known perpetrators, from dictators to middlemen, to lower ranking officials and terrorists. Their stories are explored in depth as the book examines their behaviour and motivation. Perpetrators of Mass Atrocities thus provides a comprehensive understanding of the causes of extreme mass violence. Such knowledge not only can help the international criminal justice system to be able to attribute blame in a fairer way but can also assist in preventing such atrocities being committed on the current scale.

Perpetrators of Mass Atrocities is essential reading for all those interested in war crimes, genocide, terrorism and mass violence.


Smeulers, A., M. Weerdesteijn & B. Hola (eds.) (2019), Perpetrators of international crimes – methodology, theory and evidence, Oxford: Oxford University Press.

Why would anyone commit a mass atrocity such as genocide, crimes gainst humanity, war crimes, or terrorism? This question is at the core of the multi- and interdisciplinary field of perpetrator studies, a developing field which this book assesses in its full breadth for the first time.

Perpetrators of International Crimes analyses the most prominent theories, methods, and evidence to determine what we know, what we think we know, as well as the ethical implications of gathering this knowledge. It traces the development of perpetrator studies whilst pushing the boundaries of this emerging field. The book includes contributions from experts from a wide array of disciplines, including criminology, history, law, sociology, psychology, political science, religious studies, and anthropology. They cover numerous case studies, including prominent ones such as Nazi Germany, Rwanda, and the former Yugoslavia, but also those that are relatively under researched and more recent, such as Sri Lanka and the Islamic State. These have been investigated through various research methods, including but not limited to, trial observations and interviews.


Brouwer, A.M. de & A. Smeulers (ed.) (2016). The Elgar Companion to the International Criminal Tribunal of Rwanda, Elgar.

The Elgar Companion to the International Criminal Tribunal for Rwanda is a one-stop reference resource on this complex tribunal, established in the aftermath of the 1994 genocide in Rwanda, which closed its doors on 31 December 2015. This Companion provides an insightful account of the workings and legacy of the ICTR in the field of international criminal justice.

Surveying and analysing the contributions from different disciplinary angles, the Companion is comprised of four comprehensive parts. It begins with a detailed account of the establishment of the ICTR, covering the setting up of the tribunal, its mandate, structure and personnel. The second part explores substantive law and examines issues such as genocide, crimes against humanity, war crimes, sexual violence and modes of liability. The third part discusses procedural law and explores investigation, arrest, trial/appeal, evidence, rights of the accused, rights of victims and sentencing. It concludes with the fourth part, which considers the contribution of the ICTR to international criminal justice, as well as to the lives of Rwandans.

An important contribution to the jurisprudence of international criminal courts, the Companion will appeal to academics, students and legal practitioners alike. It will be fascinating reading for anyone interested in international criminal law or the recent history of Rwanda.

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Smeulers, A. (2012). In opdracht van de staat – gezagsgetrouwe criminelen en internationale misdrijven, Tilburg: prismaprint (oratie)

International crimes are by definition forms and manifestations of collective violence. Four different forms and manifestations of international crimes can be distinguished: (1) international crimes which are committed by state authorities on orders or with the approval of the state; (2) international crimes committed by state authorities without the approval of the state; (3) international crimes committed by non-state actors on orders or with the approval of the state and (4) international crimes committed by non-state actors without approval of the state. If the state itself is involved in the crimes a political, ideological, institutional and social context is created in which the crimes are legitimized and justified. The perpetrators involved in such crimes commit their crimes out of obedience, conformism and loyalty. These perpetrators can be qualified as law-abiding citizens and seem to have little in common with ordinary and common criminals. From a criminological perspective these perpetrators can be seen as a new type of criminal. Mainstream criminological theories seem to equate criminal behaviour with deviant behaviour while in these cases the perpetrators are obedient followers rather than deviant individuals. Criminological theories are however still able to help understand the origins and causes of international crimes although in a rather limited way. Especially the strain theory and theories on social learning can be helpful in explaining international crimes. This however does not change the fact that law abiding citizens who commit international crimes on orders of the state are a different kind of perpetrators than the ordinary and common criminal. (to be downloaded here)

Smeulers, A. & F. Grünfeld (2011). International crimes and other gross human rights violations – a multi- and interdisciplinary textbook, Leiden: Brill/Martinus Nijhoff.

International crimes such as genocide, crimes against humanity and war crimes as well as other gross human rights violations are manifestations of collective violence which endanger international peace and security and warrant our full attention. It however takes a multi- and interdisciplinary approach to understand the true nature and causes of this type of criminality. The aim of this book is to take such an approach and to provide university students, scholars, professionals and practitioners within the field with the knowledge they need. The legal background and particularities of international crimes; the social context in which these crimes are committed as well as the perpetrators and bystanders thereof are studied. Within the book many case studies are presented as illustrations. (link)

Smeulers, A. (Ed.) (2010). Collective violence and international criminal justice: an interdisciplinary approach, Antwerp: Intersentia.

Extreme forms of collective violence such as genocide, crimes against humanity and war crimes can endanger international peace and security. The international criminal justice system has been set up in order to prosecute these crimes and to thus restore international peace and security. These crimes are however extremely complex social phenomena and it takes an inter- and multidisciplinary approach to understand the true nature of this type of criminality and to effectively prosecute the perpetrators thereof. This book enhances our knowledge of these complex phenomena and thus contributes to a better and more effective system of international criminal justice. Scholars from many different scientific disciplines such as law, criminology, political science, psychology, research methodology and information technology as well as practitioners from within the field have contributed to this book.

General themes in the book are: What kind of people are perpetrators of collective violence? How can we attribute criminal responsibility to individuals for crimes which are collective in nature? How can we study these crimes and how can we discover patterns of violence? What role can statistics play when holding individuals accountable? How to develop strategies of prosecution? What difficulties do prosecutors and judges face and how important and useful is the ICC Case Matrix? These are just a few of the many questions addressed in this book.

Contributors to the book are: Xabier Agirre, Kai Ambos, Olympia Bekou, Morten Bergsmo, Catrien Bijleveld, Athanasios Chouliaras, Mark Drumbl, Don Foster, Barbora Holá, Amelia Hoover Green, Annika Jones, Salim Nakhjavani, Sarah Nouwen, Mark Osiel, Stephan Parmentier, Michael Scharf, Alette Smeulers, James Waller, Wouter Werner, Martin Witteveen, Elisabeth Wood and Estelle Zinsstag. (link)

Smeulers, A. & R. Haveman (Eds.) (2008). Supranational Criminology: towards a criminology of international crimes, Antwerpen: Intersentia.

The study of international crimes, like war crimes, crimes against humanity and genocide, deserves to grow into a separate and fully fledged specialization within criminology: supranational criminology. Supranational criminology entails the study of international crimes, behaviour that shows affinity with these crimes, the causes and the situations in which they are committed, as well as interventions and their effectiveness. Interventions comprise penal systems – domestic, internationalised, supranational – in which the crimes are prosecuted and tried, as well as non-penal interventions. International crimes are studied from a criminological perspective, using the theoretical framework and research methodology of regular criminology.

By integrating all research done in other disciplines, like history, political science, sociology and psychology, criminology may contribute to the prevention of these kinds of extreme violence. What exactly entails supranational criminology? What are international crimes? Should other forms of behaviour also be qualified as international crimes? The specific characteristics of international crimes as forms of state sponsored or state facilitated crimes have to be studied. The particular methodological difficulties which arise when studying international crimes form another research topic. Explanatory theories have to be developed which can be translated into testable hypotheses. Which theories from mainstream criminology can provide answers for the prevalence or causes of international crimes? Have the international courts and tribunals succeeded in their aim? The number of topics to be studied is sheer unlimited.

This book aims to repair the fundamental and historical neglect of criminology and to break out of a state of denial by putting international crimes on the criminological agenda. (link)

About this book

‘… a must-read for anyone … who is concerned with why people commit terrible international crimes. [It] breaks a completely new ground and … is a major contribution to the literature that deserves serious attention’.

Mark A. Drumbl in New Criminal Law Review 2009 (314).

“A brilliant resource of information that the field was severely lacking until now. Supranational Criminology makes relevant and important links between criminology, international crimes and international justice. Well-written, clearly structured and easily understandable without being overly-simplistic.”

Julia Selman Ayetey, lecturer Anglia Ruskin University,(United Kingdom). 

Klip, A.H., A. Smeulers & R. Wolleswinkel (Red.) (2004). KriTies – Liber amicorum et amicarum voor prof. mr. E. Prakken, Deventer: Kluwer.

This is a liber amicorum et amicarem for Ties Prakken, professor in criminal law at Maastricht University. There are numerous chapters in the book by people who knew her well or worked with her during her log career. The chapters have been written by a large number of people. The chapters reflect the work and interest of Ties Prakken who was besides being a professor in criminal law a defence attorney. They reflect the vision of Ties who always stated that criminal law is not the goal in itself but is there to serve people. Ties was a critical thinker who was very all-round and creative. This is reflected in the chapters written by her friends, co-workers and colleagues.

Smeulers, A. (2002). In staat van uitlevering – houden uitleveringsrechters in Nederland, Duitsland en de Verenigde Staten voldoende rekening met het proces en de behandeling die de opgeëiste persoon in de verzoekende staat na uitlevering te wachten staan?, Antwerpen: Intersentia. (diss Maastricht)

Extradition law is about to change dramatically. The terrorist attacks on the US on 9/11 have made states much more willing to intensively cooperate in criminal matters. The European Arrest Warrant is one of the results of this new situation. The aim of the European Arrest Warrant is to make extradition procedures faster and smoother. Little attention is given to guaranteeing human rights. The main research question underlying this PhD research project is: To what extent does the requested state within am extradition procedure need to take the human rights situation in the requesting country into account? What factors need to be taken into account – what criteria should be used? To what extent can requested states be held responsible for human rights violations in the requesting state after extradition? How sure should a state be that the extradite will be treated well and will get a fair trial in the requesting state? Should the judge of the secretary of state decide in these matters? To what extent may policy considerations be taken into account? In the research project a comparison between the extradition procedures in the Netherlands, Germany and the United States has been undertaken. (link)