9.1 In criminal trials, the prosecution bears the burden of proof. This has been called ‘the golden thread of English criminal law’ and, in Australia, ‘a cardinal principle of our system of justice’. This principle and the related principle that guilt must be proved beyond reasonable doubt are fundamental to the presumption of innocence.
9.2 However, Parliament can reverse the onus of proof:
It has long been established that it is within the competence of the legislature to regulate the incidence of the burden of proof.
9.3 This chapter discusses the source and rationale for this principle; how this principle is protected from statutory encroachment; and when laws that reverse the onus of proof in criminal trials may be justified. The ALRC calls for submissions on two questions about this presumption.
Question 9–1 What general principles or criteria should be applied to help determine whether a law that reverses or shifts the burden of proof is justified?
Question 9–2 Which Commonwealth laws unjustifiably reverse or shift the burden of proof, and why are these laws unjustified?
9.4 The presumption of innocence developed at common law towards the end of the 18th century. In his Commentaries on the Laws of England (1765), William Blackstone said that ‘it is a maxim of English law that it is better that ten guilty men should escape than that one innocent man should suffer’.
9.5 In 1935 the UK House of Lords said the presumption of innocence principle was so ironclad that ‘no attempt to whittle it down can be entertained’. More recently, the House of Lords has said that shifting the burden of proof onto a defendant was ‘repugnant to ordinary notions of fairness’.
9.6 In the High Court of Australia, French CJ called the presumption of innocence ‘an important incident of the liberty of the subject’.
9.7 Andrew Ashworth has summarised some of the rationales for the presumption of innocence.
[T]he presumption is inherent in a proper relationship between State and citizen, because there is a considerable imbalance of resources between the State and the defendant, because the trial system is known to be fallible, and, above all, because conviction and punishment constitute official censure of a citizen for certain conduct and respect for individual dignity and autonomy requires that proper measures are taken to ensure that such censure does not fall on the innocent.
9.8 The Guide to Framing Commonwealth Offences provides that ‘placing a legal burden of proof on a defendant should be kept to a minimum’. This rule is also reflected in the Criminal Code Act 1995 (Cth) which provides that where the law imposes a burden of proof on the defendant, it should be an evidential burden, unless the law expresses otherwise.
Woolmington v DPP  AC 1 481–482 (Viscount Sankey). This statement was affirmed in Environmental Protection Authority v Caltex Refining Co Pty Ltd (1993) 178 CLR 477, 501 (Mason CJ and Toohey J). See also, Dyson Heydon, Cross on Evidence (Lexis Nexis Butterworths, 9th ed, 2012) ; Glanville Williams, The Proof of Guilt (Steven & Sons, 3rd ed, 1963) 184–5.
Sorby v The Commonwealth (1983) 152 CLR 281, 294 (Gibbs CJ). See also, Momcilovic v The Queen (2011) 245 CLR 1, 47  (French CJ). See also Heydon, above n 1, ; Williams, above n 1, 871; Andrew Ashworth and Jeremy Horder, Principles of Criminal Law (Oxford University Press, 7th ed, 2013) 71.
In Momcilovic v The Queen (2011), French CJ said: ‘The presumption of innocence has not generally been regarded in Australia as logically distinct from the requirement that the prosecution must prove the guilt of an accused person beyond reasonable doubt’: Momcilovic v The Queen (2011) 245 CLR 1, 51 .
Kuczborski v Queensland  HCA 46  (Crennan, Kiefel, Gageler & Keane JJ). The majority of the High Court was relying on the decision in The Commonwealth v Melbourne Harbour Trust Commissioners (1922) 31 CLR 1, 12, 17–18.
This chapter is about the burden of proof in criminal, rather than civil, law.
John Langbein, ‘The Historical Origins of the Privilege against Self-Incrimination at Common Law’ (1994) 92 Michigan Law Review 1047, 1070.
William Blackstone, Commentaries on the Laws of England (The Legal Classics Library, 1765) 352.
Woolmington v DPP  AC 1 .
Sheldrake v DPP  UKHL 43 .
Momcilovic v The Queen (2011) 245 CLR 1, 47  (French CJ).
Andrew Ashworth, ‘Four Threats to the Presumption of Innocence’ (2006) 10 International Journal of Evidence and Proof 241, 251.
Attorney-General’s Department, ‘A Guide to Framing Commonwealth Offences, Infringement Notices and Enforcement Powers’ (2011) 53.
Momcilovic v The Queen (2011) 245 CLR 1; Environmental Protection Authority v Caltex Refining Co Pty Ltd (1993) 178 CLR 477. There are two types of burdens: legal and evidentiary. The legal burden is ‘the obligation of a party to meet the requirement of the rule of law that a fact in issue must be proved’. The evidential burden is an obligation to show, if called upon to do so, that there is ‘sufficient evidence to raise the existence of a fact’. An evidentiary burden will be discharged where a defendant leads evidence to prove a fact in dispute or cross-examines a prosecution witness: Heydon, above n 1, . This chapter is concerned with laws that reverse or shift the legal burden of proof.
Criminal Code Act 1995 (Cth) ss 13.1–13.3.