Book excerpt: This book provides a detailed overview of the law and policy related to unlawful killings and the right to life. It is organized into the key thematic issues and types of killings that arose during the mandate of the UN Special Rapporteur on extrajudicial, summary or arbitrary executions between 2004-2016. Each chapter contains an introductory overview and selected extracts from UN Special Rapporteur reports to the United Nations General Assembly and the Human Rights Council and other normative work, and covers the applicable international law, policy considerations, and common fact scenarios. Philip Alston held the mandate of United Nations Special Rapporteur on extrajudicial, summary or arbitrary executions between 2004 and 2010; Christof Heyns did so from 2010 to 2016. This book was created to provide easy access to the work of the Special Rapporteurs, and to be a useful guide for those studying and working to promote respect for human rights. The book was edited by the two rapporteurs, together with their main advisors during their tenure as mandate holders, Sarah Knuckey and Thomas Probert.