Anthropological Witness tells the story of Alexander Laban Hinton’s encounter with an accused architect of genocide and, more broadly, Hinton’s attempt to navigate the promises and perils of expert testimony. In March 2016, Hinton served as an expert witness at the Extraordinary Chambers in the Courts of Cambodia, an international tribunal established to try senior Khmer Rouge leaders for crimes committed during the 1975–79 Cambodian genocide. His testimony culminated in a direct exchange with Pol Pot’s notorious right-hand man, Nuon Chea, who was engaged in genocide denial.