Manslaughter is a common law offence. One form of manslaughter is by criminal negligence. This form of manslaughter has the following four elements, each of which the prosecution must prove beyond reasonable doubt:
The accused owed the victim a duty of care;
The accused breached that duty by criminal negligence;
The act which breached the duty of care was committed consciously and voluntarily;
The accused’s breach of the duty caused the victim’s death (R v Sood (Ruling No 3)  NSWSC 762).
The prosecution does not need to establish any element of malice to prove negligent manslaughter (R v Lavender (2005) 222 CLR 67).
The prosecution does not need to establish that the accused’s actions were unlawful. This is one of the differences between negligent manslaughter and unlawful and dangerous act manslaughter (Wilson v R (1992) 174 CLR 313).
The accused owed a duty of care
The first element the prosecution must prove is that the accused owed the victim a duty of care (Nydam v R  VR 430).
Only a legal duty of care can give rise to liability for manslaughter. Moral duties, such as the obligation to help a stranger in distress or inform emergency services about a fire, are not relevant for this offence (R v Taktak (1988) 14 NSWLR 226).
When Does the Accused Owe a Duty of Care?
Duty to Avoid Harming Others
The common law imposes a general duty on all people who are doing a dangerous act, or who have charge of anything dangerous, to take ordinary precautions to avoid harming other people (see R v Doherty (1887) 16 Cox CC 306; Callaghan v R (1952) 87 CLR 115).
Duty to Act (Omissions)
While the accused has a duty to take care to avoid committing harmful actions, he or she will generally not have a legal duty to act in a particular manner. For example, he or she would usually not be legally required to rescue a stranger who is in danger (R v Rao  ACTSC 132).
However, there are a number of broad reasons why the accused may have a duty to act in a certain way:
Due to his or her relationship with the victim (including any contractual relationship); 
Due to a statutory obligation;
Due to the accused voluntarily assuming a duty to act; or
Due to the accused wrongfully placing a person in danger (Jones v United States of America 308 F 2d 307 (1962); R v Taktak (1988) 14 NSWLR 226; R v Reid (2010) 29 VR 446). 
The accused may have a duty to act in a certain way due to his or her relationship with the victim. For example:
A person standing in loco parentis of an infant or child owes a duty to protect the infant or child and provide adequate food, shelter, warmth and medical care. This includes a duty to intervene to stop acts of violence against the infant or child (R v Clarke & Wilton  VR 645; R v Taktak (1988) 14 NSWLR 226; R v Nicholls (1874) 13 Cox CC 75; H Ltd v J (2010) 107 SASR 352; Reynolds & Melville v R  NTSC 30; R v Russell (1933) VLR 59).
Those who live together as domestic partners (including husbands, wives and de facto partners) owe each other a duty to provide care if the other person is left helpless or unable to care for himself or herself due to injury or illness (R v Reid (2010) 29 VR 446).
Where there is a relationship of protector and protected, and the protector knows that the protected person is in peril, the protector must take steps to rescue the protected person. However, the protector does not need to jeopardise his or her own life (People v Beardsley (1907) 113 NW 1128, quoted in R v Taktak (1988) 14 NSWLR 226).
A person who has imprisoned or otherwise rendered a person helpless (e.g., a prison warden) is under a duty of care towards that person (R v Shepherd (1862) Le & Ca 147).
Parliament may create a duty of care to take certain acts or avoid specified omissions. The range of possible statutory duties is beyond the scope of this topic.
Voluntarily assumed duties
The accused may voluntarily assume a duty to care for a person who is helpless or otherwise unable to care for himself or herself due to age or infirmity. In such circumstances the accused must provide competent care (R v Stone & Dobinson  QB 354; R v Taktak (1988) 14 NSWLR 226; R v Hall  NSWSC 738; H Ltd v J (2010) 107 SASR 352).
Before a voluntarily assumed duty of care will arise, the prosecution must prove that the accused isolated the victim in such a way that others could not render assistance. It is not necessary, however, to prove that the victim was isolated for the purpose of preventing others from assisting (see R v Stone & Dobinson  QB 354; R v Taktak (1988) 14 NSWLR 226; R v Rao  ACTSC 132. But c.f. R v Hall  NSWSC 738; R v Burns  NSWDC 232).
A duty may be assumed by making some efforts to care for the person, such as providing meals, or making ineffectual attempts to obtain medical assistance (see R v Stone & Dobinson  QB 354).
Wrongful Creation of Danger
If the accused deliberately commits a wrongful act that places another person in danger, he or she owes that person a duty to take reasonable steps to render assistance and redress the danger (R v Reid (2010) 29 VR 446; R v Lawford (1993) 61 SASR 542; R v Taber (2002) 56 NSWLR 443; R v Phillips (1971) 45 ALJR 467).
Content of the Duty of Care
It can be seen from the sections above that the content of the duty of care is defined by the circumstances. For example:
The duty a parent owes a child is to protect him or her, and to provide adequate food, shelter and warmth;
The duty owed by a person who creates a danger is to take reasonable steps to redress the danger.
Where the accused is a member of a profession requiring particular skill or knowledge (such as a doctor), he or she owes a duty to exercise the skill of a reasonably competent member of that profession. He or she is not required to perform at the level expected of the most skilled member of that profession (R v Bateman (1925) 19 Cr App R 8; R v Adomako  1 AC 171).
The accused breached the duty by criminal negligence
The second element the prosecution must prove is that the accused breached the duty of care by criminal negligence (Nydam v R  VR 430; R v Osip (2000) 2 VR 595; Wilson v R (1992) 174 CLR 313).
This requires the accused’s act or omission to have fallen so far below the standard of care a reasonable person would have exercised, and to have involved such a high risk of death or really serious injury, that the act or omission merits criminal punishment (R v Lavender (2005) 222 CLR 67; Wilson v R (1992) 174 CLR 313; Andrews v DPP  AC 576; R v Bateman (1925) 19 Cr App R 8; R v A C Hatrick Chemicals (1995) 152 A Crim R 384; R v Richards & Gregory  2 VR 1).
This is the same degree of negligence required to establish negligently causing serious injury (R v Shields  VR 717; R v De’Zilwa (2002) 5 VR 408). For the offence of culpable driving by gross negligence to be committed, a jury does not need to consider whether an accused’s act or omission merits criminal punishment (Bouch v R  VSCA 86).
Whether this means that the degree of negligence required to establish that offence differs from that required to establish the offence of manslaughter by criminal negligence or negligently causing serious injury is not clear. Where relevant, judges should seek submissions from parties as to whether the degree of negligence required for each of these offences differs
The test for criminal negligence imports a community standard, which determines whether the breach was sufficiently severe to warrant criminal punishment (R v Mitchell  VSCA 304).
Negligence that would support civil liability (i.e., that the accused fell short of the standard of care that would have been taken by a reasonable person in the circumstances) is not sufficient to establish criminal negligence. The prosecution must establish such a high degree of negligence, involving disregard for the life and safety of others, as to amount to a crime and be deserving of punishment (Nydam v R  VR 430; Andrews v DPP  AC 576; R v Bateman (1925) 19 Cr App R 8; Cittadini v R  NSWCCA 302; R v Wright  3 VR 355).
A "significant departure" from the standard of care required is not sufficient. Judges should ensure that their directions do not lower the degree of negligence required (see R v De’Zilwa (2002) 5 VR 408).
While a test of liability that requires proof that the act or omission merits criminal punishment involves a degree of circularity, the question is one of degree that cannot be defined more precisely (R v Adomako  1 AC 171).
The nature of the duty of care may be relevant when determining the seriousness of any breach. For example, where the duty arises because of the accused’s deliberate wrongful conduct (e.g., where the accused injured the victim), the accused’s obligation to remedy the danger created may be quite strict (e.g., he or she may be required to secure medical attention, even if the victim initially refuses). A failure to act accordingly may be viewed as a serious breach (see R v Reid (2010) 29 VR 446).
In directing the jury on the degree of negligence required, a comparison between civil and criminal negligence is often helpful (R v Shields  VR 717).
Objective nature of criminal negligence
The test for criminal negligence is objective. The jury must compare the acts or omissions of the accused against the behaviour expected of a hypothetical reasonable person in the situation of the accused (R v Richards & Gregory  2 VR 1; R v Lavender (2005) 222 CLR 67; R v Sam  NSWSC 803).
The element will only be met if a reasonable person would have realised that the accused’s acts or omissions created a high risk of death or really serious injury (R v Richards & Gregory  2 VR 1; R v Lavender (2005) 222 CLR 67; R v Sam  NSWSC 803).
As the test for negligence is objective, the prosecution does not need to prove that the accused intended to cause death or really serious injury, or that the accused knew that his or her conduct would likely cause death or really serious injury. Those states of mind would establish murder (R v Lavender (2005) 222 CLR 67; Nydam v R  VR 430; R v Sam  NSWSC 803).
The accused’s belief or opinion about whether he or she was in breach of the duty of care is not relevant. The jury must make its own assessment of whether the acts or omissions were negligent, based on the information available to a reasonable person in the position of the accused at the time of the events in question (R v Lavender (2005) 222 CLR 67; R v Reid (2010) 29 VR 446; R v Taylor (1983) 9 A Crim R 358). 
It does not matter whether or not the accused was capable of meeting the relevant standard. Matters such as the accused’s inability to meet the standard, or deficiencies in the accused’s reasoning processes, are relevant only to sentencing (R v Richards & Gregory  2 VR 1).
In some cases, common practice within a field may be relevant to determining whether the accused breached the standard of care by acting in the way that he or she did. However, there are occasions when common industrial practice is negligent (see Dovuro Pty Ltd v Wilkins (2003) 215 CLR 317; Cittadini v R  NSWCCA 302).
The reasonable person in the position of the accused
The test for criminal negligence requires the jury to determine how the reasonable person of ordinary fortitude and strength of mind, in the position of the accused, would have acted in the circumstances. In making this determination, the reasonable person should be considered to be the same age as the accused, and to have any specialised knowledge and experience that the accused had (R v Edwards  SASC 303; R v Taylor (1983) 9 A Crim R 358; R v Sam  NSWSC 803; R v Lavender (2005) 222 CLR 67).
However, the reasonable person should not be considered to have any of the accused’s deficiencies in reasoning capabilities, or to have been suffering from any injuries that affected the accused’s reasoning processes at the relevant time, such as concussion (R v Edwards  SASC 303).
The reasonable person also does not share the accused’s beliefs, values or attitudes (R v Sam  NSWSC 803).
Guard against risks of hindsight
The mere fact that a person to whom the accused owed a duty of care died does not mean the accused must have been criminally negligent. A duty of care to avoid a particular risk is not a duty to ensure that the risk does not eventuate (Cittadini v R  NSWCCA 302; Gordon v Ross  NSWCA 157; R v Smith  VSCA 92).
It is therefore important to ensure that the jury does not reason that the accused must have been criminally negligent because otherwise the event in question would not have occurred. The jury should take care not to use the benefits of hindsight when determining the degree of negligence (see Cittadini v R  NSWCCA 302; Gordon v Ross  NSWCA 157; R v Smith  VSCA 92).
Negligence and recklessness
The difference between negligent manslaughter and reckless murder lies in the state of mind of the accused and the degree of foresight regarding the consequences of his or her actions, rather than in the degree of carelessness (Pemble v R (1971) 124 CLR 107 per Menzies J).
While, in ordinary language, the type of behaviour necessary to meet the test of criminal negligence might be described as "reckless", judges should avoid using that term because of the risk of confusion that arises from the meaning of recklessness in the law (R v Adomako  1 AC 171; La Fontaine v R (1976) 136 CLR 62 per Gibbs J).
The relevant act was voluntary
The third element that the prosecution must prove is that the act which breached the duty of care was committed consciously, voluntarily and deliberately (Ryan v R (1967) 121 CLR 205; R v Haywood  VR 755; R v Winter  VSCA 144; R v Williamson (1996) 67 SASR 428).
While the prosecution does not need to prove that the accused intended to cause death, they must still prove that the relevant act was committed consciously and voluntarily (R v Haywood  VR 755; R v Vollmer  1 VR 95).
While the law predominantly focuses on the need for an act to be voluntary, there may be cases where the defence argues that an omission is involuntary. In such cases, the judge may need to direct the jury on the need to prove that the omission was conscious, voluntary and deliberate. Alternatively, the judge may identify an act within the omission and may instruct the jury to consider whether the accused committed that act consciously, voluntarily and deliberately.
The breach of the duty of care caused the victim’s death
The fourth element that the prosecution must prove is that the breach of the duty of care caused the victim’s death (R v Adomako  1 AC 171; Cittadini v R  NSWCCA 302).
As the prosecution must prove that it was the accused’s criminal breach of the duty of care that caused the death, it is important that the judge precisely identify the act or omission alleged to have caused the victim’s death (Cittadini v R  NSWCCA 302; Justins v R (2010) 79 NSWLR 544).
Where the evidence reveals more than one possible breach of duty, the judge must decide, based on the factual circumstances, whether the separate breaches may be aggregated into a single breach for the purposes of causation (R v Pace & Conduit (Ruling No 2)  VSC 308).
The prosecution must disprove any relevant defences, including self-defence, duress and emergency (R v Edwards  SASC 233. See also Crimes Act 1958 ss9AE, 9AG, 9AI).
Civil law principles relating to contributory negligence, consent and voluntary assumption of risk do not provide a defence to a charge of negligent manslaughter. The jury may, however, take the victim’s conduct into account when determining whether the second element has been met (i.e., whether the accused acted with criminal negligence) (R v Cato  1 WLR 110; R v Edwards  SASC 303. But c.f. R v Fleeting [No 1]  1 NZLR 343; R v Storey  NZLR 417; R v Jones  11 Cox CC 544).
In some cases the accused will allege that he or she had an honest and reasonable belief in a set of facts which, if true, would have rendered the conduct innocent. In such cases, the prosecution does not need to disprove this allegation. The issue of an accused’s honest and reasonable mistake of fact should be considered as part of the second element (i.e., as part of the jury’s determination of whether the accused’s acts or omissions were criminally negligent) (R v Osip (2000) 2 VR 595; R v Lavender (2005) 222 CLR 67).
Where manslaughter is left as an alternative to murder and the issue of self-defence arises, the jury may need to consider self-defence separately for each offence. The fact that the jury excludes self-defence as a defence to murder does not invariably mean that they must also exclude it as a defence to manslaughter.
The ordinary principles of accessorial liability are capable of applying to manslaughter (Giorgianni v R (1985) 156 CLR 473; R v Chai (2002) 187 ALR 436; Markby v R (1978) 140 CLR 108). See Part 5: Complicity for information concerning these principles.
Intentional or reckless murder
A judge must leave manslaughter as an alternative verdict to intentional or reckless murder if there is a "viable" case available on the evidence. See Alternative Verdicts.
The jury may only return a verdict on manslaughter as an alternative to murder if it unanimously agrees that the accused is not guilty of murder. In the event of a disagreement on the verdict for murder, the jury cannot return a verdict of "at least manslaughter" (Stanton v R (2003) 198 ALR 41; Gammage v R (1969) 122 CLR 444; R v McCready  VR 325).
Unlawful and dangerous act manslaughter
The prosecution does not need to specify a particular form of manslaughter in a charge. That is a matter for particulars. A single charge of manslaughter may encompass both unlawful and dangerous act manslaughter and negligent manslaughter without raising duplicity issues (see, e.g., R v Cramp (1999) 110 A Crim R 198; R v Isaacs (1997) 47 NSWLR 374).
The judge should not direct the jury on both unlawful and dangerous act manslaughter and negligent manslaughter if the issues are relevantly identical and there is a risk that the directions would confuse the jury. Such confusion is particularly likely when the judge leaves manslaughter as an alternative to reckless murder. The judge should generally resolve this situation by directing on one form of manslaughter the jury can understand and apply (R v Windsor  VR 89; R v Edwards  SASC 233).
In determining which form(s) of manslaughter to leave to the jury, the judge should consider whether there is a practical prospect of the jury reaching different conclusions on the two forms of manslaughter, and whether omitting a form of manslaughter may prejudice the prosecution or the accused (R v Windsor  VR 89).
Manslaughter as an accessory
The obligation to leave a viable case of manslaughter to a jury as an alternative to a charge of murder includes an obligation to instruct the jury on appropriate forms of accessorial liability for manslaughter (R v Makin (2004) 8 VR 262. See also R v Panozzo  VSCA 245; R v Nguyen (2010) 242 CLR 491).
Judges must be careful to only leave appropriate forms of accessorial liability to the jury. Leaving an inappropriate form of accessorial liability may deprive the accused of an opportunity of being acquitted of murder and convicted on a form of manslaughter that is reasonably open on the evidence (R v Makin (2004) 8 VR 262. See also R v Panozzo  VSCA 245). See Part 5: Complicity for information concerning the different forms of accessorial liability.
Manslaughter and Unanimity
In some cases it may be necessary to direct the jury that they must be unanimous about a particular matter (in addition to being unanimous about whether or not the accused is guilty of manslaughter).
In addressing this issue, a distinction is drawn between three types of cases:
Those in which alternative legal bases of liability are proposed by the prosecution;
Those in which alternative factual bases of liability are proposed by the prosecution; and
Those in which one offence is charged, but a number of discrete acts are relied upon as proof, any of which would entitle the jury to convict (R v Walsh (2002) 131 A Crim R 299; R v Klamo (2008) 18 VR 644; R v Cramp (1999) 110 A Crim R 198).
While a specific unanimity direction will not be required in the first type of case, such a direction will be necessary in the second and third types. For more information on this topic and sample charges, see Unanimous and Majority Verdicts.
 While provocation has been abolished as a partial defence to murder (Crimes Act 1958 s3B), it remains available as a partial defence for offences alleged to have been committed prior to 23 November 2005.
 Where the relationship arises out of a contract, see Cittadini v R  NSWCCA 302; R v Instan  1 QB 450; R v Marriott (1838) 8 C & P 425.
 In some cases, failure to comply with a duty to act may found liability for murder (e.g., where the accused intended, by his or her failure, to kill or really seriously injure the victim) (see R v Taber (2002) 56 NSWLR 443; R v Phillips (1971) 45 ALJR 467; R v Gibbons & Proctor (1918) 13 Cr App R 134).
 However, the accused’s subjective beliefs may be relevant for certain defences, such as self-defence and emergency (see R v Edwards  SASC 233).