The maximum penalty for manslaughter is 25 years imprisonment: s 24. Since the offence covers a wide variety of circumstances, calling for a wide variety of penal consequences, determining an appropriate sentence for manslaughter is “notoriously difficult”: R v Green [1999] NSWCCA 97 at [24]. Although some assistance may be received from a consideration of facts of other cases and the sentences imposed therein, those cases do not determine an inflexible range: R v Green at [24].

Spigelman CJ said in R v Forbes [2005] NSWCCA 377 at [133]–[134]:

In R v Blacklidge (unrep, 12/12/95, NSWCCA), Gleeson CJ said:

Similar observations were made in R v MacDonald (unrep, 12/12/95, NSWCCA).

In R v Dawes [2004] NSWCCA 363, a case involving the killing of a severely disabled 10-year-old boy by his mother, Dunford J said at [31]:

An assessment of the objective criminality of an offence of manslaughter will depend on the factual findings made by the sentencing judge: R v MD [2005] NSWCCA 342 at [62]. In that case it was also said at [65]:

Where the offence of manslaughter involves either an intention to kill or an intention to cause grievous bodily harm, the degree of harm the offender knows will be caused by the offence may be highly relevant to their moral culpability: Sheiles v R [2018] NSWCCA 285 at [29]–[39]. See also Murder — Aggravating factors and cases that attract the maximum at [30-040].

There is a degree of overlap in sentencing for murder and manslaughter, and a higher sentence may be warranted in a manslaughter case than in a murder case, although ordinarily a conviction for murder would attract a greater penalty: R v Hoerler [2004] NSWCCA 184 at [26]–[28], [30].

It is very difficult to identify any pattern of sentencing: R v Hill (unrep, 18/6/81, NSWCCA). Limited assistance is to be derived from sentences in other cases: Taber v R [2007] NSWCCA 116 at [102].

Statistical data on sentencing for manslaughter is similarly of limited assistance; reliance on such data has been described as “unhelpful and even dangerous”: R v Vongsouvanh [2004] NSWCCA 158 at [38]. Sentencing statistics for manslaughter are of such limited assistance that they should be avoided: R v Wood [2014] NSWCCA 184 at [59].

Manslaughter by unlawful and dangerous act does not involve an intention to kill or inflict grievous bodily harm. However, the unlawful and dangerous act involved must be an intentional and voluntary one and it must be established that a reasonable person in the position of the accused would have realised that he or she was exposing the victim to an appreciable risk of serious injury: Wilson v The Queen (1992) 174 CLR 313 at 333.

Although there is no murderous intent involved in manslaughter by unlawful and dangerous act, there will be cases where a heavy sentence will be appropriate: R v Maguire (unrep, 30/8/95, NSWCCA). In that case James J said:

Where the unlawful and dangerous act is of high objective gravity, the offence may be assessed as so grave as to warrant the maximum penalty. For example, in Clare v R [2008] NSWCCA 30, the unlawful and dangerous act was anal intercourse with a three-year-old child, causing the child to vomit and asphyxiate. McClellan CJ at CL said that the “abuse of a 3 years old child for sexual gratification by anal penetration resulting in death is a crime of utmost gravity”: Clare v R at [48].

It is not a matter in mitigation that an offender neither desired nor contemplated the deceased’s death; if the offender had so contemplated, there would be liability for murder: R v Chapple (unrep, 14/9/93, NSWCCA).

Manslaughter by criminal negligence arises when the accused does an act “consciously and voluntarily without any intention of causing death or grievous bodily harm but in circumstances which involved such a great falling short of the standard of care which a reasonable man would have exercised and which involved such a high risk that death or grievous bodily harm would follow that the doing of the act merited criminal punishment”: Nydam v The Queen [1977] VR 430 at 445, approved in The Queen v Lavender (2005) 222 CLR 67 at [136].

In R v George [2004] NSWCCA 247, the offender failed to provide proper care (nutrition, hydration, medication and medical care) for his 86-year-old mother, for whom he was the primary carer. On appeal against sentence, the court said at [19]:

The sentence was reduced to 3½ years imprisonment with a non-parole period of 2 years. The court, however, thought it necessary to state that “at the most, other cases can do no more than become part of a range of sentencing, which in the case of manslaughter is wider than for any other offence”: R v George at [48].

Many cases of manslaughter by criminal negligence involve the failure of parents to obtain medical assistance for their children following the infliction of injuries: R v Wilkinson [1999] NSWCCA 248 (non-parole period of 3½ years, additional term of 3 years); R v Eriksson [2001] NSWSC 781 (non-parole period of 18 months, balance of 18 months); Hill v R [2003] NSWCCA 16 (non-parole period of 4½ years, balance of 1½ years). In R v O’Brien [2003] NSWCCA 121, the offender failed to have her 14-month-old child hospitalised when advised by medical practitioner that urgent hospitalisation was required. A non-parole period of 3 years, with a balance of 2 years was imposed. In dismissing the appeal against sentence, Dunford J said at [74]:

In BW v R [2011] NSWCCA 176, the court accepted the offending involved was in the worst category (as that concept was understood prior to The Queen v Kilic (2016) 259 CLR 256): BW v R at [63], [73]. In that case, the applicant’s 7-year-old daughter died after a period of “protracted and cruel neglect where the applicant showed not a shred of care to [her] suffering … over a long period of time”: BW v R at [63]. The court concluded that the non-parole period of 12 years with a balance of term of 4 years while heavy was well within range: BW v R at [73].

Significant sentences may be imposed in other cases of criminal negligence involving members of the public. In R v Simpson [2000] NSWCCA 284, the deceased died by coming into contact with an electric wire system erected by the offender to protect an area of land used to grow marijuana. A non-parole period of 6 years and balance of 3 years was imposed; see also R v Cameron (unrep, 27/9/94, NSWCCA), where a non-parole period of 8 months and balance of 1 year and 4 months was imposed. The conduct in Davidson v R [2022] NSWCCA 153 was considered to be an unprecedented and “very serious” example of criminally negligent conduct with “catastrophic consequences” involving as it did one act of criminally negligent driving causing the death of four children walking on a public footpath and injury to three other children: [40] (Brereton JA); [138] (Adamson J); [333]–[334] (N Adams J). The offender’s appeal on the basis of manifest excess was allowed, by majority, and he was re-sentenced to an aggregate sentence of 20 years with a non-parole period of 15 years (reduced from 28 years with a non-parole period of 21 years).

Under s 23 Crimes Act 1900, murder is reduced to manslaughter where the act or omission causing death was done or omitted under provocation. The partial defence is available where the act or omission is the result of a loss of self control induced by the deceased’s conduct where that conduct could have induced an ordinary person in the position of the accused to have so far lost self control as to have formed an intent to kill or inflict grievous bodily harm.

Reference to other provocation cases may not be helpful. Barr J said R v Green [1999] NSWCCA 97 at [32]:

It has been said many times that provocation is a concession to human frailty: R v Chhay (unrep, 4/3/94,NSWCCA) Gleeson CJ at 11. In R v Morabito (unrep, 10/6/92, NSWCCA), Wood J said that “manslaughter, even though committed under provocation, is recognised as a major crime and is one which calls for a correspondingly grave measure of criminal justice being meted out to the guilty party”; see also R v Bolt [2001] NSWCCA 487 at [58].

Factors relevant to the determination of the level of culpability in provocation cases were set out by Hunt CJ at CL in R v Alexander (unrep, 26/10/94, NSWSC):

In R v Cardoso [2003] NSWCCA 15 at [10], the court acknowledged the sentencing judge’s application of R v Alexander, above, at 144 as a “familiar discussion of the approach to sentence for provocation manslaughter”.

In R v Bolt, above, at [35] it was observed that “as a matter of logic, the degree of provocation must reduce the objective gravity of the offence, and also the degree of violence employed must increase the objective gravity of the offence”. It was also noted that extreme provocation may be accompanied by excessive violence, pointing in opposite directions on the question of objective gravity: R v Bolt at [36], [46]. A strong adherence to particular values may be relevant to the gravity of the provocative act: R v Khan (unrep, 27/5/96, NSWCCA).

In exceptional cases involving a history of domestic violence perpetrated by the deceased a non-custodial sentence may be appropriate: R v Bogunovich (unrep, 30/5/85, NSWSC); R v Alexander, above, at 145.

The authors of the Judicial Commission monograph Partial Defences to Murder in New South Wales 1990–2004 identified 65 cases where offenders were sentenced upon the basis of provocation defences between 1990 and 2004: see p 8 and the list at p 84 of the publication.

Section 23A Crimes Act 1900 provides that murder is reduced to manslaughter where a person’s capacity to understand events, or to judge whether the person’s actions were right to wrong, or to control himself or herself, was substantially impaired because of a mental health impairment or cognitive impairment, provided the impairment was “so substantial as to warrant liability for murder being reduced to manslaughter.” Section 23A(8)(a) provides that the person is entitled to be acquitted on the ground that the person was not criminally responsible because of mental health impairment or cognitive impairment. Section 23A(8) defines cognitive impairment for the purposes of s 23A.

As in the case of manslaughter by provocation, what is ordinarily involved in manslaughter by substantial impairment is a conclusion that the taking of human life was the consequence of a deliberate and voluntary act, performed with intent to kill or cause grievous bodily harm, or with reckless indifference to human life: R v Blacklidge (unrep, 12/12/95, NSWCCA).

The relevant impairment diminishes — but does not negate — the offender’s responsibility: Blacklidge, above; R v Dawes [2004] NSWCCA 363 at [34]; see also R v Low (unrep, 13/8/91, NSWCCA). As stated in R v Low, “it is quite wrong to take the view that merely because there is an element of diminished responsibility, which substantially impairs a person’s judgment, that that is the end of the matter and a light sentence must inevitably follow”: at 18. In R v Cooper (unrep, 24/2/98, NSWCCA), Gleeson CJ said, “in some circumstances, a case of manslaughter based on diminished responsibility could attract the maximum penalty for manslaughter”. In one case involving five counts of manslaughter by diminished responsibility, the offender was sentenced to concurrent head terms of 25 years imprisonment with non-parole periods of 18 years: R v Evers (unrep, 16/6/93, NSWCCA). At the other end of the spectrum, the offenders in R v Sutton [2007] NSWSC 295 received five-year good behaviour bonds for the manslaughter by substantial impairment of their severely disabled son.

It is necessary for a sentencing judge to consider the degree to which an offender’s mental condition was impaired beyond that required to make out the partial defence: R v Keceski (unrep, 10/8/93, NSWCCA). While an impairment of greater degree may tend towards a further diminution in culpability, it may also raise the issue of future dangerousness. As stated in Veen v The Queen [No 2] (1988) 164 CLR 465 at 477, where the offender’s sentence of life imprisonment for manslaughter (the maximum penalty at the time) was upheld by the High Court at 476–477:

In Catley v R [2014] NSWCCA 249, it was held that the sentencing judge did not err in finding that the offender’s mental condition (psychosis) did not play a great part in the commission of the offence and to the extent that it did, the concomitant reduction in his culpability had already been taken into account because he had been found guilty of manslaughter rather than murder.

For a historical summary of the law and cases in this area, see the Judicial Commission monograph Partial Defences to Murder in New South Wales 1990–2004 where the authors identified 56 diminished responsibility and 18 substantial impairment cases between 1990 and 2004: see pp 8 and 80–82 of the publication.

Excessive self-defence has an ephemeral history as a partial defence. After a number of lower court rulings, the High Court confirmed it as a partial defence in Viro v The Queen (1978) 141 CLR 88, but later abolished it in Zecevic v DPP (Vic) (1987) 162 CLR 645 at 664. It was resurrected by Parliament in NSW in the Crimes Amendment (Self-Defence) Act 2002. The partial defence to murder of excessive self-defence appears in s 421 Crimes Act 1900, which commenced operation on 22 February 2002. It applies to offences whenever committed, except where proceedings were instituted before the commencement of the provision: s 423.

Section 421(1) provides the defence of excessive self-defence reduces murder to manslaughter if:

The defence is available where a person uses lethal force and the conduct is not a reasonable response in the circumstances as he or she perceives them, but the person believes the conduct is necessary to defend himself or herself or another person or to prevent the unlawful deprivation of liberty. If the act causing death is deliberate and is committed with the intent to kill the deceased or inflict grievous bodily harm, an accused is guilty of manslaughter where it is found that there was a reasonable possibility that the accused believed his or her conduct was necessary in his or her own self-defence, but where the fact finder is satisfied beyond reasonable doubt that his or her response was not reasonable in the circumstances as he or she perceived them to be: Ward v R [2006] NSWCCA 321 at [41].

Where a plea of manslaughter on the basis of excessive self-defence is accepted by the Crown, all the elements of murder are present and it is for the court to determine whether the offender intended to kill or commit grievous bodily harm, or acted with reckless indifference to human life: Grant v R [2014] NSWCCA 67 at [64], [66]; Lane v R [2013] NSWCCA 317 at [50]. It is an acceptance by the offender that his or her mental state was one which, but for the availability of excessive self-defence in s 421 Crimes Act, was sufficient to amount to murder: Grant v R at [66]. The state of mind must be proved beyond reasonable doubt: Grant v R at [77]. The circumstances can vary widely. For example, in R v Nguyen [2013] NSWCCA 195, the respondent discharged his pistol and the bullet struck a police officer in the upper arm. Another police officer then discharged his weapon at the offender, however, the bullet struck the victim’s neck and he later died in hospital. The Crown accepted the plea on the basis of excessive self-defence, that is, he did not know the victim was a police officer and there was a reasonable possibility that he genuinely believed it was necessary to shoot at the victim whom he believed intended to rob him.

The emphasis in s 421 on the response of an offender “in the circumstances as he or she perceives them” requires a sentencing judge to make a finding as to what the offender perceived the circumstances to be, and to evaluate the degree to which the conduct departed from what would have been a reasonable response to those circumstances as perceived: Smith v R [2015] NSWCCA 193 at [45], [56], [59]. Both questions are central to the sentencing exercise where excessive self-defence is made out: Smith v R at [45], [59].

In Smith v R, the sentencing judge erred by failing to make a direct or express finding of what the applicant perceived the circumstances to be. The content of the applicant’s belief was never clearly articulated. The lack of any finding or reference to the circumstances “as perceived” by the applicant had repercussions in the evaluation of the degree to which the applicant’s response was unreasonable: Smith v R at [36], [61].

Certain of these principles and others were summarised in Newburn v R [2022] NSWCCA 139 at [39] as follows:

Events leading to a confrontation are relevant only insofar as they provide context to the actual offence: Newburn v R at [41].

Manslaughter by excessive self-defence is a crime “committed under conditions of fear of varying degrees of extremity”: R v Trevenna [2004] NSWCCA 43 at [46], applied in Ward v R [2006] NSWCCA 321 at [59], [70]–[72].

As in other categories of manslaughter, the relevant circumstances vary over a wide range: R v Forbes [2005] NSWCCA 377 at [135]. In Vuni v R [2006] NSWCCA 171 the court said that the statistical sample for cases involving excessive self-defence (approximately 10 cases by the time the appeal was heard) was too small to be of any real practical value: at [31]. James J said in R v Williamson [2008] NSWSC 686 at [40] that, although there have been many cases of excessive self-defence manslaughter, these cases do not establish a tariff. The cases “exhibit a wide degree of variation in their facts, which is typical of cases within any category of manslaughter” but nevertheless, provide some limited guidance.

In cases where more than one partial defence is established, a more lenient sentence is likely to be warranted than would be the case if only one partial defence applied: R v Low (unrep, 13/8/91, NSWCCA). In R v Ko [2000] NSWSC 1130, Kirby J found that both the provocation by the deceased and the offender’s substantial impairment constituted “significant extenuating circumstances”: R v Ko at [41]. See, for a historical summary, the Judicial Commission monograph Partial Defences to Murder in New South Wales 1990–2004 which identifies 10 cases where offenders were sentenced upon the basis of two partial defences between 1990 and 2004, including R v Anthony (unrep, 23/09/94, NSWSC); R v Chaouk (unrep, 17/8/93, NSWSC); R v Diamond (unrep, 15/4/94, NSWSC); R v Gardner (unrep, 27/3/92, NSWSC); R v Kali (unrep, 27/5/91, NSWSC); R v K [1999] NSWSC 933; and R v Spencer (unrep, 18/12/92, NSWSC).