In the aftermath of the Myall Creek massacre trials of late 1838,  historians have argued that a code of silence descended on the frontier and that o the rapidly expanding frontier, the act of massacre became more  difficult to detect.  The publication of Stage 1 of the online map of frontier massacres in Eastern Australia 1788-1872,  offers a new source of data to assess the assertion. The paper  makes four important findings: the use of poison as a weapon to kill Aboriginal people; that massacre was increasingly likely to be an opportunity event, that is, carried out without  a specific reason; that a significant number of massacres were carried out by agents of the state; and that although a code of silence operated on some frontiers, such as Gippsland and the Clarence River, on others such as the Western District of the Port Phillip District and in Northern District of New South Wales, the evidence of massacre was often reported in the colonial press; in the colonial legislature and British Parliamentary Papers. The paper concludes that  in the aftermath of Myall Creek, the incidence of frontier massacre increased  and the characteristics became more complex in reflecting local conditions.