General criminal law principles

Contributed by MichaelCrowley and current to 27 July 2018

Innocent until proven guilty

A fundamental cornerstone of Western democracies is the principle that an accused person is presumed innocent until proven guilty of committing an offence. The presumption of innocence, however, is lost either upon a guilty finding following a trial or upon entering a guilty plea. A finding of guilt must be based upon the law that is current at the time of the alleged offending. A retrospective application of enacted laws is rare. However, the High Court of Australia has held that the Australian Constitution (1901) does not prevent the Australian Parliament from enacting retrospective laws. See, for example; Polyukhovich v Commonwealth [1991] HCA 32; (1991) 172 CLR 501 and the Criminal Code Amendment (Anti-Hoax and other Measures) Act 2002 (Cth).

Proof beyond reasonable doubt

The Crown or Prosecution has the task of proving the guilt of an accused person beyond reasonable doubt. In the famous English case of Woolmington v DPP [1935] AC 462, the principle was expressed as ‘one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner’s guilt...[beyond] reasonable doubt’.

The meaning of the words ‘beyond reasonable doubt’ in criminal law keeps to its common everyday English language meaning. The meaning was confirmed in Green v R[1971] HCA 55; (1971) 126 CLR 28 when the High Court reminded trial judges that in summing up in a criminal trial on the onus of proof ‘...it is a mistake to depart from the time-honoured formula...’.

The role of the prosecution includes negating any defences that an accused may raise. Should the accused raise special defences such as insanity, the accused must prove that defence on the civil standard; that is, on the balance of probabilities.

The right to remain silent

This right to remain silent is matched to an extent by a right to ask questions.

However, once a person clearly expresses his or her intention to remain silent that right should be honoured, subject to specific statutory exceptions. These statutory exceptions do not directly infringe the common law’s right to silence: the right not to speak. It removes the right not to incriminate oneself.

The right not to incriminate oneself has been removed by certain laws that require a person to answer questions or produce documents with the caveat that those answers or documents will not be admissible against the person in criminal proceedings. See, for example, s 3ZZGE(1)(c)Crimes Act 1914 (Cth); ss 34L(8) and 34L(9) Australian Security Intelligence Organisation Act 1979 (Cth) and Bartlett v The Queen [No 10] [2014] WASC 277.

A court cannot draw an adverse inference because an accused person exercises a right to silence (see, for example; R v Swaffield (1998) 192 CLR 159, Micalizzav WA [2013] WASCA 96 (11 April 2013) and more specifically on the right to silence: Azzopardi v R [2001] HCA 25; (2001) 205 CLR 50). Although the decision in Weissensteiner v R [1993] HCA 65; [1993] 178 CLR 217 is an exception to this principle, subsequent decisions have confirmed the uniqueness of the Weissensteiner decision. Consequently, the Weissensteiner decision does not have general application.

Police officers have powers under the Criminal Investigation (Identifying People) Act 2002 (WA) to ask for personal details when the police officer reasonably suspects that the person has committed or is about to commit, or can help in a criminal investigation (s 16). These powers include removal of any face covering worn by the person (s 16(4A)(b)). A failure to comply with such requests is an offence (s 16(6)).

Double jeopardy

The principle of ‘double jeopardy’ prevents an accused person being put on trial a second time for the same offence. In WA, Part 5A Criminal Appeals Act 2004 (WA) provides an exception to this principle and may lead to a new trial if ‘fresh and compelling evidence’ is found concerning a serious offence carrying a term of 14 years or more. In Queensland, the threshold is much higher at 25 years.

Ignorance of the law

Ignorance of the law is not a justification, excuse (or a defence) to a criminal offence unless knowledge of the law is expressly stated as an element of the offence (see s 22 Criminal Code).