The sixth-century Digest of Justinian (22.3.2) provides, as a general rule of evidence: Ei incumbit probatio qui dicit, non qui negat—"Proof lies on him who asserts, not on him who denies". It is there attributed to the second and third century jurist Julius Paulus Prudentissimus. It was introduced in Roman criminal law by emperor Antoninus Pius.
According to Talmud, "every man is innocent until proved guilty. Hence, the infliction of unusual rigours on the accused must be delayed until his innocence has been successfully challenged. Thus, in the early stages of the trial, arguments in his defence are as elaborate as with any other man on trial. Only when his guilt has become apparent were the solicitous provisions that had been made to protect defendants waived".
The presumption of innocence is fundamental to Islamic law where the principle that the onus of proof is on the accuser or claimant is strongly held, based on a hadith documented by Imam Nawawi. "Suspicion" is also highly condemned, this also from a hadith documented by Imam Nawawi as well as Imam Bukhari and Imam Muslim.
After the collapse of the Western Roman Empire, the West began to practice feudal law, which was a synthesis of aspects of Roman law as well as some Germanic customs according to the new elite, including presumed guilt. For instance, the accused could prove his innocence by having twelve people swear that he could not have done what he was accused of. In practice, this tended to favor the nobility over the lower classes, whose witnesses risked being seen as less credible.
Trials by ordeal were common from the 6th century until the early 13th century, and were known to continue into the 17th century in the form of witch-hunts. Whilst common in early Germanic law, compurgation was formally adopted in Rome by Pope Innocent III in 1215 at the Fourth Lateran Council and trials by fire and water specifically were forbidden. This was during the period of development of the jus commune, the canon law of the Catholic Church influenced the common law during the medieval period
In the early 13th century, Louis IX of France banned all trials by ordeal and introduced the presumption of innocence to criminal procedures. It was during the seventh crusade that he had witnessed the presumption of innocence in practice by the ruling Muslims and sought to adopt and implement this law on his return to France . As a reformer, this and other legal and economic reforms led to him being the only canonized king of France.
Sir William Garrow coined the phrase "presumed innocent until proven guilty", insisting that defendants' accusers and their evidence be thoroughly tested in court
"Presumption of innocence" serves to emphasize that the prosecution has the obligation to prove each element of the offense beyond a reasonable doubt (or some other level of proof depending on the criminal justice system) and that the accused bears no burden of proof. This is often expressed in the phrase "presumed innocent until proven guilty", coined by the British barristerSir William Garrow (1760–1840) during a 1791 trial at the Old Bailey. Garrow insisted that accusers be robustly tested in court. An objective observer in the position of the juror must reasonably conclude that the defendant almost certainly committed the crime. In 1935, in its judgment of Woolmington v Director of Public Prosecutions, the English Court of Appeal would later describe this concept as being 'the golden thread' running through the web of English criminal law. Garrow's statement was the first formal articulation of this.
The presumption of innocence was originally expressed by the French cardinal and canonical juristJean Lemoine in the phrase "item quilbet presumitur innocens nisi probetur nocens (a person is presumed innocent until proven guilty)", based on the legal inference that most people are not criminals. However, this referred not merely to the fact that the burden of proof rests on the prosecution in a criminal case, but the protections which a defendant should be given: prior notice of the accusation being made against them, the right of confrontation, right to counsel, etc. It is literally considered favorable evidence for the accused that automatically attaches at trial. It requires that the trier of fact, be it a juror or judge, begin with the presumption that the state is unable to support its assertion. To ensure this legal protection is maintained, a set of three related rules govern the procedure of criminal trials. The presumption means:
With respect to the critical facts of the case—whether the crime charged was committed and whether the defendant was the person who committed the crime—the state has the entire burden of proof.
With respect to the critical facts of the case, the defendant does not have any burden of proof whatsoever. The defendant does not have to testify, call witnesses or present any other evidence, and if the defendant elects not to testify or present evidence, this decision cannot be used against them.
The jury or judge is not to draw any negative inferences from the fact the defendant has been charged with a crime and is present in court and represented by an attorney. They must decide the case solely on evidence presented during the trial.
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...
The Universal Declaration of Human Rights, article 11, states: "Everyone charged with a penal offence has the right to be presumed innocent until proven guilty according to law in a public trial at which he has had all the guarantees necessary for his defense."
Articles 8 (1) and 8 (2) (right to a fair trial), in conjunction with Article 1 (1) (obligation to respect and ensure rights without discrimination), of the American Convention on Human Rights make the Inter-American Court to stress that "the presumption of innocence is a guiding principle in criminal trials and a foundational standard for the assessment of the evidence. Such assessment must be rational, objective, and impartial in order to disprove the presumption of innocence and generate certainty about criminal responsibility. ... The Court reiterated that, in criminal proceedings, the State bears the burden of proof. The accused is not obligated to affirmatively prove his innocence or to provide exculpatory evidence. However, to provide counterevidence or exculpatory evidence is a right that the defence may exercise in order to rebut the charges, which in turn the accusing party bears the burden of disproving".
In the Colombian constitution, Title II, Chapter 1, Article 29 states that "Every person is presumed innocent until proven guilty according to the law".
In France, article 9 of the Declaration of the Rights of Man and of the Citizen of 1789, which has force as constitutional law, begins: "Any man being presumed innocent until he has been declared guilty ..." The Code of Criminal Procedure states in its preliminary article that "any person suspected or prosecuted is presumed innocent for as long as their guilt has not been established" and the jurors' oath repeats this assertion (article 304; note that only the most serious crimes are tried by jury in France). However, there exists a popular misconception that under French law, the accused is presumed guilty until proven innocent.
In Italy, the second paragraph of Article 27 of the Constitution states: "A defendant shall be considered not guilty until a final sentence has been passed."
In Romania, article 23 of the Constitution states that "any person shall be presumed innocent until found guilty by a final decision of the court".
The Constitution of Russia, in article 49, states that "Everyone charged with a crime shall be considered not guilty until his or her guilt has been proven in conformity with the federal law and has been established by the valid sentence of a court of law". It also states that "The defendant shall not be obliged to prove his or her innocence" and "Any reasonable doubt shall be interpreted in favor of the defendant".
In the South African Constitution, section 35(3)(h) of the Bill of Rights states: "Every accused person has a right to a fair trial, which includes the right to be presumed innocent, to remain silent, and not to testify during the proceedings."
In New Zealand, the New Zealand Bill of Rights 1990 provides at section 25 (c) "Everyone who is charged with an offence has, in relation to the determination of the charge, the following minimum rights: (c) the right to be presumed innocent until proved guilty according to law".
In the United Kingdom changes have been made affecting this principle. Defendants' previous convictions may in certain circumstances be revealed to juries. Although the suspect is not compelled to answer questions after formal arrest, failure to give information may now be prejudicial at trial. Statute law also exists which provides for criminal penalties for failing to decrypt data on request from the police. If the suspect is unwilling to do so, it is an offence. Citizens can therefore be convicted and imprisoned without any evidence that the encrypted material was unlawful. Furthermore, in sexual offence cases such as rape, where the sexual act has already been proved beyond reasonable doubt, there are a limited number of circumstances where the defendant has an obligation to adduce evidence that the complainant consented to the sexual act, or that the defendant reasonably believed that the complainant was consenting. These circumstances include, for example, where the complainant was unconscious, unlawfully detained, or subjected to violence.
In Canadian law, the presumption of innocence has been reinforced in certain instances. The Criminal Code previously contained numerous provisions according to which defences to certain offences were subject to a reverse onus: that is, if an accused wishes to make that defence, they had to prove the facts of the defence to a balance of probabilities, rather than the Crown having to disprove the defence beyond a reasonable doubt. This meant that an accused in some circumstances might be convicted even if a reasonable doubt existed about their guilt. In several cases, various reverse onus provisions were found to violate the presumption of innocence provision of the Canadian Charter of Rights and Freedoms. They were replaced with procedures in which the accused merely had to demonstrate an "air of reality" to the proposed defence, following which the burden shifted to the Crown to disprove the defence.
Bill C-51, An Act to amend the Criminal Code and the Department of Justice Act and to make consequential amendments to another Act, received Royal Assent in December 2018. Among other things, it eliminated several reverse onus provisions from the Criminal Code, some of which had previously been found unconstitutional, and others pre-emptively in order to avoid further Charter challenges.
^The Presumption of Guilt in the Investigation of Tax Evasion Crimes, Juridical Tribune, Vol. 8, Issue 1 (March 2018), p. 33.
^I/A Court H.R., Case of Zegarra Marín v. Peru. Preliminary Objections, Merits, Reparations and Costs. Judgment of February 15, 2017. Series C No. 331: so, "the Court highlighted that to guarantee the presumption of innocence, especially as regards criminal conviction by trial, to reasoned judgment is imperative. It must state the sufficiency of the prosecution's evidence, observe the rules of sound judicial discretion in evaluating the evidence, including that which could generate doubt as to criminal responsibility, and lay out the final findings of the assessment of evidence. Only then can a trial court disprove the presumption of innocence and sustain a conviction beyond reasonable doubt. Where there is any doubt, the presumption of innocence and the principle of in dubio pro reo should play a decisive role in the judgment".