Current discourse on the representation of genocide claims that we are experiencing ‘the shift from the era of the witness to the era of the perpetrator’. This raises ethical concerns over why and how documentaries engage with perpetrators. Based on an assessment of 203 documentaries on seven genocides, my article makes three kinds of contribution in addressing these concerns: (1) It discusses the ethics of representing perpetrators in archival footage, reenactments or interviews in a wider corpus than those covered in recent discussions. (2) It uncovers a broad range of ethical reasons for why documentary filmmakers engage with perpetrators, rather than seeking to establish a singular ethical ground for this engagement. This approach can do better justice to the varying cultural, historical and political contexts of the respective genocides, the different production contexts and target audiences of the documentaries, and the different styles and types of documentaries that inform the ethics of perpetrator representation. (3) It introduces two broad categories of perpetrator representation in documentaries that conceptualize the ethical purposes of this engagement differently.