In what ways is the conduct of prosecutors constrained by the presumption of innocence? To address this question, I first develop an account of the presumption in the trial context, according to which it is a vital element in a moral assurance procedure for the justified infliction of legal punishment. Jurors must presume the factual innocence of defendants at the outset of trials and then be convinced beyond a reasonable doubt by the government’s evidence before they convict defendants. Prosecutors’ responsibilities (...) to promote the integrity of this moral assurance procedure are then divided into pre-trial, during-trial, and post-trial phases. Since most charge adjudication is effected through plea bargaining, the ways in which plea procedures must be modified to conform to this moral assurance procedure, and thus honor the presumption of innocence, are also discussed. (shrink)