The dependence of colonisation on police was a core feature both of settler colonies and of colonial dependencies, from the middle of the nineteenth century to the post-war decline of the British Empire. After playing a key role in securing settlement against Indigenous resistance police agencies in most jurisdictions settled into a more domesticated magement of social order. On still remote frontiers in northern Australia evidence of violent policing could still provoke inquiry and even prosecution of individual cases, though with limited effect. In this article we examine one such event, the death in 1933 of an Aborigil woman at Borroloola in the Gulf Country of Australia's Northern Territory, and the subsequent (and rare) prosecution of a policeman over her death. The factors shaping a decision to prosecute such a case, and those limiting the achievement of a measure of justice, are examined against a background of changing practices in the policing of late colonial frontiers.