As international society has globalized, so too has crime. Both countries and the collective international community have struggled to deal with criminal activity that has global proportions and effects - from international crimes like genocide and war crimes to transnational crimes like terrorism and trafficking. The systems of law designed to suppress these crimes are complex and often poorly understood; thus, this book brings together a concise and lucid explication and analysis of international and transnational criminal law. A collaboration between leading legal scholars Robert J. Currie, Gillian MacNeil, and Justin J. Mohammed, this book is designed to help those who work in criminal law and international law respectively speak the legal language of the other, and to provide accessible explanations of the legal tools and doctrines. It highlights the work of international courts, the use of treaties, and the investigational techniques that operate in this area, but its focus on Canada makes it an invaluable resource for Canadian lawyers, judges, researchers, students and law enforcement personnel. This updated and revised 4th edition builds on the success of earlier editions, which have been cited by the Supreme Court of Canada and other Canadian courts, in providing up-to-date accounts of international developments, Canadian case law and practice, and relevant literature.