In practice
Because a defendant is presumed to be innocent, the prosecution has the burden of proving the defendant's guilt on every element of each criminal charge beyond a reasonable doubt. To do so, the prosecution must present compelling evidence that leaves little real doubt in the mind of the trier of fact (the judge or jury) that the defendant is almost certainly guilty. For any reasonable doubt to exist, it must come from insufficient evidence, or conflicts within the evidence, that would leave an impartial factfinder less than fully convinced of the defendant's guilt. Accordingly, the standard of proof forces the factfinder to ignore unreasonable doubts—doubts that are frivolous, hypothetical, or not logically linked to the evidence—and to consider evidence favoring the accused, since reasonable doubt entitles them to an acquittal. The term "reasonable doubt" can be criticised for having aBy jurisdiction
Medieval Roman law, followed by the English juristUnited Kingdom
England and Wales
In English common law prior to the reasonable doubt standard, passing judgment in criminal trials had severe religious repercussions for jurors. According to judicial law prior to the 1780s, "the Juryman who finds any other person guilty, is liable to the Vengeance of God upon his Family and Trade, Body and Soul, in this world and that to come."James Q. WhitmaJuries are always told that, if conviction there is to be, the prosecution must prove the case beyond reasonable doubt. This statement cannot mean that in order to be acquitted the prisoner must "satisfy" the jury. This is the law as laid down in the Court of Criminal Appeal in ''Rex v. Davies'' 29 Times LR 350; 8 Cr App R 211, the headnote of which correctly states that where intent is an ingredient of a crime there is no onus on the defendant to prove that the act alleged was accidental. Throughout the web of the English Criminal Law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner's guilt subject to what I have already said as to the defence of insanity and subject also to any statutory exception. If, at the end of and on the whole of the case, there is a reasonable doubt, created by the evidence given by either the prosecution or the prisoner, as to whether the prisoner killed the deceased with a malicious intention, the prosecution has not made out the case and the prisoner is entitled to an acquittal. No matter what the charge or where the trial, the principle that the prosecution must prove the guilt of the prisoner is part of the common law of England and no attempt to whittle it down can be entertained.
Canada
In Canada, the expression "beyond a reasonable doubt" requires clarification for the benefit of the jury. The leading decision is '' R. v. Lifchus'', where the Supreme Court discussed the proper elements of a charge to the jury on the concept of "reasonable doubt" and noted that " e correct explanation of the requisite burden of proof is essential to ensure a fair criminal trial." While the Court did not prescribe any specific wording that a trial judge must use to explain the concept, it recommended certain elements that should be included in a jury charge, as well as pointing out comments that should be avoided. The Supreme Court suggested that the concept of proof beyond a reasonable doubt should be explained to juries as follows: * The standard of proof beyond a reasonable doubt is inextricably intertwined with that principle fundamental to all criminal trials, the presumption of innocence. * The burden of proof rests on the prosecution throughout the trial and never shifts to the accused. * A reasonable doubt is not a doubt based upon sympathy or prejudice and, instead, is based on reason and common sense. * Reasonable doubt is logically connected to the evidence or absence of evidence. * Proof beyond a reasonable doubt does not involve proof to an absolute certainty. It is not proof beyond any doubt, nor is it an imaginary or frivolous doubt. * More is required than proof that the accused is probably guilty. A jury that concludes only that the accused is probably guilty must acquit. The Court also warned trial judges that they should avoid explaining the concept in the following ways: * By describing the term ''reasonable doubt'' as an ordinary expression that has no special meaning in the criminal law context. * By inviting jurors to apply to the task before them the same standard of proof that they apply to important, or even the most important, decisions in their own lives. * By equating proof "beyond a reasonable doubt" to proof "to a moral certainty". * By qualifying the word "doubt" with adjectives other than ''reasonable'', such as ''serious'', ''substantial'', or ''haunting'', which may mislead the jury. * By instructing jurors that they may convict if they are "sure" that the accused is guilty, before providing them with a proper definition as to the meaning of the words ''beyond a reasonable doubt''. The Supreme Court of Canada has since emphasized in '' R. v. Starr'' that an effective way to explain the concept is to tell the jury that proof beyond a reasonable doubt "falls much closer to absolute certainty than to proof on a balance of probabilities." It is not enough to believe that the accused is probably guilty, or likely guilty. Proof of probable guilt, or likely guilt, is not proof beyond a reasonable doubt.New Zealand
In New Zealand, jurors are typically told throughout a trial that the offence must be proved "beyond reasonable doubt", and judges usually include this in the summing-up. There is no absolute prescription as to how judges should explain reasonable doubt to juries. Judges usually tell jurors that they will be satisfied beyond reasonable doubt if they "feel sure" or "are sure" that the defendant is guilty. In line with appellate court direction, judges do little to elaborate on this or to explain what it means. Research published in 1999 found that many jurors were uncertain what "beyond reasonable doubt" meant. "They generally thought in terms of percentages, and debated and disagreed with each other about the percentage certainty required for 'beyond reasonable doubt', variously interpreting it as 100 per cent, 95 per cent, 75 per cent and even 50 per cent. Occasionally this produced profound misunderstandings about the standard of proof." In '' R v Wanhalla'', President Young of the Court of Appeal set out a model jury direction on the standard of proof required for a criminal conviction.United States
The cornerstone to American criminal jurisprudence is that the accused is presumed innocent until guilt is proved beyond a reasonable doubt.'' In re Winship'' TheJapan
Since 1945, Japan has also operated by a "reasonable doubt" standard, including the doctrine of '' in dubio pro reo'', which was instituted by the Supreme Court during a controversial murder trial in 1975 (the Shiratori case brought before the Supreme Court of Japan, see for example notes on Shigemitsu Dandō). However, this is not considered an essential standard in Japan and lower level judges sometimes disregard it.See also
References
{{Criminal due process, doubt, state=expanded Sociology of law Skepticism American legal terminology Criminal law Criminal procedure Legal doctrines and principles Law of Canada Legal reasoning Doubt