Polish lawyer Rafael Lemkin coined the word genocide in his 1944 book Axis Rule in Occupied Europe and spent much of his life advocating for international laws that forbade the practice. In this documentary, director Edet Belzberg (Children Underground) intercuts Lemkin’s story with profiles of Benjamin Ferencz (chief prosecutor at the Nuremberg trials and still a tireless human rights activist in his 90s) and Samantha Power (U.S. ambassador to the United Nations and a former journalist who covered the Srebrenica massacre of 1995), as well as accounts of genocide in Armenia, Rwanda, Syria, and Sudan. Given all that material, the movie feels too short at two hours; it offers a worthwhile overview of the subjects but doesn’t treat any of them in much depth.