This article seeks to explain how Mau Mau combatants selected and killed their civilian targets. The central argument is that Mau Mau members shared a moral logic that informed whom they killed, how, and why they did it. This moral logic was partly based on traditional Kikuyu ethics of violence, which were widely held and traceable to the late nineteenth century. Yet it was also a logic born out of novel, albeit contested, ethical convictions that developed in the context of an asymmetrical anticolonial war in 1950s-Kenya. Using captured guerrilla documents and oral history interviews with Mau Mau veterans, the article analyzes the perceived offenses that civilians committed against Mau Mau, the motives of Mau Mau assailants, and the internal conflicts that arose regarding the killings of some civilians. Ultimately, this article demonstrates that the moral logic of Mau Mau killings was firmly rooted in a dialectical tension between longstanding Kikuyu ethics of violence and the harsh realities of waging an asymmetrical anticolonial war. It also shows that Mau Mau debates over who to kill formed part of a larger process of sacralization, whereby members of the movement reimagined what they deemed sacred, moral, and just measures for conducting the war.