This article is concerned with what constitutes interference with the presumption of innocence and what justifications there might be for such interference. It provides a defence of a theory of the presumption of innocence that suggests that the right is interfered with if the offence warrants conviction of defendants who are not the intended target of the offence. This thesis is defended against two alternative theories. It then considers what might justify interference with the presumption of innocence. It explores the idea that interference is justified if it is necessary in a democratic society and considers the presumption in relation to the aims of the criminal trial. It is concluded that no good grounds have been provided for interference with the right, and that the right should be regarded as inviolable.