What is crime, and what must the prosecution prove to convict?
Examine the meaning of crime and the elements that must be proved beyond reasonable doubt
A focused answer on the meaning of crime and the two elements the prosecution must prove (actus reus and mens rea), the standard and burden of proof, strict liability exceptions, and a worked HSC past exam question.
Have a quick question? Jump to the Q&A page
What this dot point is asking
NESA wants you to know what constitutes a crime, the two elements the prosecution must prove, the standard and burden of proof, and the strict liability exception. Expect a 4-6 mark short-answer question in Section II that tests precise terminology.
The answer
Defining a crime
A crime is an act or omission against the community that is punishable by the state under the criminal law. It is distinct from a civil wrong (tort, breach of contract), which is between two private parties and resolved by damages or another civil remedy.
Crimes can be created by statute (the Crimes Act 1900 (NSW) is the main NSW criminal statute) or by the common law. Most modern offences in NSW are statutory.
The two elements
The prosecution must prove two elements to convict.
1. Actus reus (the guilty act). The physical element. Conduct (an act or omission), circumstances (the surrounding context) and consequences (any result). Murder under the Crimes Act 1900 (NSW) s 18 requires an act causing death. Robbery under s 94 requires the taking of property from the person of another with force or threats.
2. Mens rea (the guilty mind). The mental element. The accused must have acted with the relevant fault state: intention, knowledge, recklessness, or (rarely) negligence. The required mens rea differs offence by offence. Murder requires intention to kill or to inflict grievous bodily harm, or reckless indifference to human life.
The leading authority on the requirement of mens rea is He Kaw Teh v The Queen (1985) 157 CLR 523, in which the High Court held that mens rea is presumed for serious offences unless Parliament has clearly displaced it.
Standard and burden of proof
The burden of proof is on the prosecution. The accused does not have to prove their innocence.
The standard of proof is beyond reasonable doubt. The jury (or magistrate in summary matters) must be satisfied that no reasonable doubt remains. This is the highest standard in Australian law, reflecting the seriousness of a criminal conviction and the protection of liberty.
Strict liability offences
Some statutory offences displace mens rea and are strict liability. Common examples include traffic offences (e.g. exceeding the speed limit under the Road Transport Act 2013 (NSW)) and certain regulatory offences. The prosecution need only prove the actus reus. Strict liability is justified on grounds of public safety, regulatory efficiency, and the relatively low penalty involved.
Past exam questions, worked
Real questions from past NESA papers on this dot point, with our answer explainer.
2019 HSC4 marksDescribe the elements of a crime that the prosecution must prove.Show worked answer →
A 4-mark response needs both elements named, defined and linked to the standard of proof.
Actus reus is the guilty act. It is the physical element of the offence: the conduct, the circumstances surrounding the conduct, and any consequences. For example, in a murder charge under the Crimes Act 1900 (NSW) s 18, the actus reus is the act causing the death of the victim.
Mens rea is the guilty mind. It is the mental element of the offence: the intention, knowledge, recklessness or negligence with which the accused acted. For murder, the mens rea is an intention to kill or to inflict grievous bodily harm, or reckless indifference to human life, as confirmed in He Kaw Teh v The Queen (1985) 157 CLR 523.
The prosecution must prove both elements beyond reasonable doubt. If either element is missing or only proved on the balance of probabilities, the accused must be acquitted.
Markers reward (1) both elements named with the Latin terms, (2) a working definition of each, (3) the standard of proof, (4) reference to legislation or a leading case.
Related dot points
- Investigate the categories of crime (offences against the person, against property, against the state, drug offences, traffic offences, public order, preliminary, regulatory) and the special category of strict liability offences
A focused answer to the categories of crime in NSW, with examples drawn from the Crimes Act 1900 (NSW), the Drug Misuse and Trafficking Act 1985 (NSW), and the Summary Offences Act 1988 (NSW), plus the special category of strict liability offences.
- Investigate the criminal investigation process, including police powers, the arrest process, the right to silence, and the bail decision
A focused answer to police powers and the criminal investigation process in NSW. Covers LEPRA powers (search, arrest, detain), the rights of suspects (right to silence, caution), the bail decision under the Bail Act 2013 (NSW), and recent NSW bail reforms.