On 16 November 2018, the Extraordinary Chambers in the Courts of Cambodia in Judgement of Case 002/02 were satisfied that there was sufficient evidence to establish both the actus reus and the mens rea necessary to constitute the crime against humanity of murder with regard to surgical experimentation. In arriving at this decision, the ECCC relied on, among other things, the Medical Case decided at Nuremberg. However, in the Medical Case, unlawful medical experiments were classified under both crimes against humanity and war crimes. Moreover, under the Rome Statute for the International Criminal Court, unlawful medical experiments are only criminalised as war crimes. What is more, they are not explicitly included under the rubric of crimes against humanity, even though at Nuremberg, the same offence was classified both as a war crime and as a crime against humanity. This chapter explores the twists and turns in the historical development of the law on unlawful medical experimentation in order to outline a clearer future for defining an approach to better understanding the contours of this crime.