A legal presumption that benefits a defendant in a criminal case and which results in acquittal in the event that the prosecutor does not prove guilt beyond a reasonable doubt.
The presumption of innocence was fully discussed in an 1895 United States Supreme Court decision, Coffin v United States, for which the citation is 156 US 432:
"The presumption of innocence is a conclusion drawn by the law in favor of the citizen, by virtue whereof, when brought to trial upon a criminal charge, he must be acquitted, unless he is proven to be guilty."
In speaking on behalf of the Court in the Coffin decision, Mr. Justice White reflected on this insightful anecdote from Roman law:
"Numerius, the governor of Narbonensis, was on trial before the Emperor, and, contrary to the usage in criminal cases, the trial was public.
"Numerius contented himself with denying his guilt, and there was not sufficient proof against him.
His adversary, Delphidius, a passionate man, seeing that the failure of the accusation was inevitable, could not restrain himself, and exclaimed, "Oh, illustrious Caesar! If it is sufficient to deny, what hereafter will become of the guilty?" to which Julian replied, "If it suffices to accuse, what will become of the innocent?"
Blackstone, in his Commentaries on the Laws of England, famously remarked on topic that: "the law holds that it is better that ten guilty persons escape than that one innocent suffer."
In Canada, the presumption forms part of the Charter of Rights and Freedoms where, at ¶11(d):
"Any person charged with an offence has the right ... to be presumed innocent until proven guilty according to law in a fair and public hearing by an independent and impartial tribunal."