Accounting and the conscious secretive killing of humans are rarely concurrently examined in the contemporary and historical literature. Based on examinations of a rare and formerly highly secretive surviving written record found in the Venice State Archive, and other surviving primary records, as well as secondary sources, this novel study outlines evidence of “accounting for killing” of the enemies of the Venetian State during the sixteenth century as a means of rendering the individuals who made those decisions “accountable for death”. The rationale for this governmental approach to self-preservation, described as “Reason of State”, was widely adopted in Europe during this period. The available evidence illustrates the use of the police apparatus in the Venetian State, namely the Council of Ten, in order to reinforce, protect and defend the State, and illuminates the role of accounting information in this highly secretive and sinister process. The notion of “secretive collective internal horizontal accountability” is applied in explaining the accountability for death regime found to have been adopted, thus broadening the dimensions of accountability that are typically recognized within the accounting literature. Rarely has accounting and accountability within government been shown to be so secretive.