defendant. Total sentence of imprisonment of 22 years and 6 months, comprising a non-parole period of 16 years and 10 months commencing 12 July 2013 and a balance term of 5 years and 8 months to conclude on...
Key principles
A sentence for murder must be informed by the statutory purposes in s 3A of the Crimes (Sentencing Procedure) Act 1999 and established common law sentencing principles including...
Post-mortem conduct, where it forms part of the facts and circumstances of the offence, may be taken into account in assessing objective criminality; it need not be separately...
The fact that an offender was present in the victim's home does not automatically operate as an aggravating feature under s 21A(2)(eb) where the offender was likely there with...
A prior record of violent and domestic offences is a legitimate aggravating factor under s 21A(2)(d), but consideration of such antecedents must avoid double punishment (Veen and...
Issues before the court
What is the appropriate objective criminality range for the killing?
Can post-mortem mutilation be taken into account as a statutory aggravating factor (gratuitous cruelty) or only as part of objective seriousness?
Plain English Summary
Garling J sentenced Shannon Mahon for the murder of his de facto partner, concluding that the offending was very serious and above mid-range because of brutal assault, manual strangulation, post-mortem burning with a hot iron, concealment and deceit. Aggravating features included prior domestic violence convictions and offending while on bail; the house-location was not treated as aggravating because Mahon was likely present with the victim's consent. A full 25% discount was allowed for an early guilty plea. The head sentence of 30 years was reduced to a total of 22 years 6 months, with a non-parole period of 16 years 10 months commencing 12 July 2013.
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Deep Dive
1,852 words · generated 18/07/2026
What happened
On 11 January 2013 Shannon David Mahon violently attacked and killed his de facto partner, Ms Julie Grant, at her home at The Entrance, New South Wales. The fatal injuries comprised severe blunt force trauma to the head and neck and manual strangulation; the forensic pathologist opined that the combination of head and neck injuries, including manual strangulation, caused death. After death, the offender inflicted a full-thickness contact burn to the perineal area (left groin, labia majora and left upper thigh), an injury the specialist burn surgeon considered consistent with an iron used while hot. The body was concealed behind a bedhead in a small space between the bedframe and a gyprock wall; surrounding bedroom damage and shards of broken lamp glass were present on the body. Mahon denied knowledge to police and lied to friends about the deceased’s whereabouts before being arrested on 12 January 2013. He remained in custody from arrest. He pleaded guilty to murder in November 2013 and was sentenced in the NSW Supreme Court by Garling J on 6 February 2015 (see factual findings and the medical/forensic evidence in the judgment).
Is the fact that the offence occurred in the victim's home an aggravating factor where the offender was present by the victim's consent?
What discount for a plea of guilty is appropriate where the plea was entered at the first reasonable opportunity?
Cited legislation
No linked legislation citations have been extracted yet.
Prior events are critical context. In late November 2012 Mahon assaulted the deceased and her son; an Apprehended Violence Order followed and Mahon was convicted and placed on bail with conditions requiring him to live elsewhere; he breached that order and was later convicted for the contravention. At the time of the murder he had returned to live at the house contrary to the AV O and bail conditions.
Garling J fixed a head sentence of 30 years’ imprisonment, applied the full 25 per cent discount for an early guilty plea, and therefore imposed a total sentence of 22 years 6 months, with a non-parole period of 16 years 10 months. Because a Local Court sentence had commenced on 12 January 2013 and was to run to 11 August 2013, the Supreme Court adjusted commencement so that the murder sentence began on 12 July 2013. The result was custody from 12 July 2013, non-parole until 11 May 2030, and full term to 11 January 2036.
Why the court decided this way
Structure of the sentencing task
Garling J proceeded by identifying the statutory purposes of sentencing (s 3A of the Crimes (Sentencing Procedure) Act 1999) and the established common law sentencing principles: proportionality, parity, totality and avoidance of double punishment. The judge identified relevant statutory aggravating and mitigating features in s 21A and was careful to separate matters relevant to objective criminality from matters personal to the offender.
Assessment of objective criminality
The crucial factual matrix informed the primary sentencing instinct. The court described the criminality as “very serious” and explicitly placed it “above the mid-range of criminality” for murder (see the judge’s assessment of the brutality, strangulation and post-mortem burn). The features driving that assessment were:
A brutal and sustained attack causing head and neck injuries in the home of the victim;
Manual strangulation as part of the lethal process;
A post-mortem, contact full-thickness burn to the genital/perineal area inflicted with a hot iron, a deliberate act of mutilation and indignity;
Concealment of the body behind the bedhead and deliberate deception and falsehoods to others following the killing.
The post-mortem mutilation was treated as part of the objective facts; Garling J accepted that post-mortem conduct, if proximate to the assault, can be taken into account in assessing objective seriousness (the court referenced authority on taking such conduct into account and elected to count the iron injury in the overall assessment rather than separately as a statutory gratuitous cruelty aggravation).
Aggravating and mitigating factors
Aggravation acknowledged by the court included Mahon’s earlier convictions for domestic violence and his offence of contravening an Apprehended Violence Order (s 21A(2)(d)), and his status on bail (conditional liberty) at the time of the offending (s 21A(2)(j)). The house-of-victim statutory aggravation (s 21A(2)(eb)) was considered but rejected because the judge was satisfied Mahon was likely present with the victim’s consent despite the AV O, the court followed DS v R and declined to elevate the venue to a statutory aggravation in the circumstances. The plea of guilty was accepted as having been entered at the first reasonably available opportunity and the judge applied the maximum practical discount of 25 per cent. Mitigation otherwise was modest: there was limited reliable material on remorse, limited weight was afforded to psychological history provided only through an untested expert account, and rehabilitation prospects were judged poor or unresolved.
Deterrence, denunciation and personal protection
Garling J placed significant emphasis on general deterrence and denunciation because the crime was domestic violence, a class of offending requiring strong community condemnation and a sentencing focus on deterrence, both personal and general, consistent with prior authority and legislative sentencing purposes.
Sentencing calculus
The judge's discretionary balancing produced a head sentence of 30 years (reflecting the high degree of objective criminality), discounted by 25 per cent for the early plea, leading to the operative 22 years 6 months with a 16 years 10 months non-parole period. Commencement was adjusted to acknowledge the earlier Local Court-imposed custody.
Before and after state of the law
Before this decision
The relevant sentencing law and principles were well established before Garling J’s remarks: s 3A and s 21A of the Crimes (Sentencing Procedure) Act 1999 set out statutory purposes and aggravating/mitigating factors; High Court and Court of Criminal Appeal authorities (Muldrock, Markarian, Veen, Pearce, etc.) supplied the common-law scaffolding on proportionality, assessment of objective seriousness and the proper application of plea discounts.
After this decision
The judgment applies those principles to a set of particularly brutal facts and confirms several practical propositions likely to be of ongoing utility:
Post-mortem mutilation that is proximate to the assault can be considered in assessing objective criminality as part of the facts rather than necessitating separate statutory categorisation as gratuitous cruelty;
The house-of-victim aggravation under s 21A(2)(eb) is not automatic where the offender was present by consent or at the victim’s invitation; DS v R was followed as controlling authority on that point;
Conditional liberty breaches continue to carry significant aggravation weight;
The full 25 per cent plea discount remains available where an early plea is made at the first reasonable opportunity.
This sentence therefore reinforces established sentencing approaches rather than displacing prior law, illustrating how the statutory factors are applied in the context of domestic homicide with post-mortem mutilation.
Key passages with plain-English translation
"In my assessment, the criminality was very serious. It was above the mid-range of criminality for offences of this kind."
Plain English: The judge considered the killing worse than what would usually be judged a mid-level murder; the conduct was particularly bad.
"He has then inflicted a further gruesome burning injury on the deceased in the immediate post-mortem period."
Plain English: After the victim died, the offender used a hot iron to burn the victim's genitals; the judge treated that as an additional horrific act.
"He is entitled to the maximum level of discount of 25 per cent in these circumstances."
Plain English: Because the offender pleaded guilty as early as reasonably possible, he got the largest standard reduction in sentence for a guilty plea.
"I am not satisfied on the evidence before me that Mr Mahon is unlikely to re-offend, nor am I satisfied that he has good prospects of rehabilitation."
Plain English: The court was not convinced that the offender has changed or will not commit offences again, so this did not reduce the sentence.
"Accordingly, the appropriate date for commencement of the sentence for this offence is 12 July 2013."
Plain English: The judge set the start date for this sentence to recognise prior custody imposed for related offences.
Each passage is rooted in the judge's exercise of discretion: description of facts, identification of aggravation/mitigation, and concrete sentencing mechanics.
What fact patterns trigger this precedent
This decision is informative where the following are present:
A fatal domestic assault involving both significant blunt force trauma and manual strangulation;
Post-mortem mutilation inflicted close in time to the assault (for example, contact burns inflicted after death);
Evidence that the offender attempted to conceal the body and deliberately misled acquaintances or authorities;
Prior convictions for domestic violence and/or a proven breach of an Apprehended Violence Order or bail relating to the same victim;
An early guilty plea entered at the first reasonably available opportunity;
Limited or untested evidence of remorse and equivocal rehabilitation prospects.
In short, the judgment is a guide for cases where a partner kills in a domestic context, has a history of domestic violence, commits post-mortem indignity and deception, and seeks mitigation principally through an early plea and psychological narrative.
How later courts have treated it
Garling J’s decision is principally a sentencing exercise applying established principles; it does not create novel law. Later courts will treat this judgment as an application of sentencing principles to specific facts rather than as an authority to change doctrine. It reinforces the following practice points which later courts will note and apply:
Consideration of post-mortem mutilation as part of objective criminality (consistent with prior authorities);
Application of DS v R on the question whether a dwelling aggravates sentence where the offender was tolerated or present with consent;
The acceptability of applying the full 25 per cent plea discount where the plea was timely.
Because the judgment rests on fact-specific assessments, appellate courts would be unlikely to disturb it absent a demonstrable error in reasoning or misapplication of sentencing principles.
Still-open questions
Threshold for treating post-mortem conduct as a separate statutory aggravation vs part of objective facts: Garling J declined to treat the iron burn as a discrete statutory aggravation in the circumstances. Future cases might test whether more extensive or different types of post-mortem mutilation should be counted in addition to objective seriousness as separate statutory aggravation under s 21A(2)(f).
Quantification of plea discounts in extreme factual scenarios: while the full 25 per cent was applied here, debate continues about the extent to which plea discounts should be constrained in cases of extreme gravity, and whether a statutory cap should be formalised.
The interplay of consent-to-presence and the house-of-victim aggravation: the decision endorses DS v R’s approach, but factual fine distinctions (for example, coercion or the practical inability to leave) may produce different results.
Weight to be accorded to expert psychological reports prepared on the basis of offender-provided history when the offender does not give sworn evidence: Garling J gave such material limited weight; future appellate consideration could refine the boundaries for admissibility and weight.
Concluding note: R v Mahon is a fact-intensive sentencing judgment that illustrates how the statutory list of aggravating/mitigating features and settled common law sentencing principles are applied where domestic homicide is accompanied by post-mortem mutilation and a history of domestic violence. It is most useful as a roadmap for sentencing practice rather than as a source of new doctrinal rules.
Catchwords
CRIMINAL LAW - sentencing - murder(1984) 154 CLR 606
Markarian v The Queen [2005] HCA 25(2005) 228 CLR 357
Mill v The Queen [1988] HCA 70(1988) 166 CLR 59
Muldrock v The Queen [2011] HCA 39(2011) 244 CLR 120
Pearce v The Queen [1988] HCA 57 (1998) 194 CLR 610
R v Dunn [2004] NSWCCA 41(2004) 144 A Crim R 180
R v Edigarov (2001) 125 A Crim R 551
R v Hamid [2006] NSWCCA 302
Judgment (25 paragraphs)
[1]
REMARKS ON SENTENCE
On 11 January 2013, Mr Shannon David Mahon murdered Ms Julie Grant at her home at The Entrance in New South Wales.
He did so by severely beating her around the head and neck in a violent assault, and then by strangling her. After she died, he continued to assault her by using an iron to inflict a burn injury on the perineal area between her buttocks. Ms Grant died in her home as a consequence of the injuries which Mr Mahon inflicted.
Mr Mahon was arrested on 12 January 2013, and has been in custody ever since. He was charged with murder. In November 2013, Mr Mahon pleaded guilty to murder. On 20 November 2013, he was committed by the Local Court at Wyong to the Supreme Court for sentence. On 19 September 2014, when arraigned in the Supreme Court, Mr Mahon adhered to his plea of guilty to murder.
It is now time for Mr Mahon to be sentenced for his crime.
The Crimes Act 1900 provides a maximum term of life imprisonment for the offence of murder. The Crimes (Sentencing Procedure) Act 1999 provides for a standard non-parole period of 20 years. Although this is not directly applicable in this case because of Mr Mahon's plea of guilty, it, together with the maximum penalty, nevertheless remains as a relevant guidepost to which the Court may have regard: Muldrock v The Queen [2011] HCA 39; (2011) 244 CLR 120.
[2]
Judicial Task on Sentencing
In the circumstances of this present case, it is appropriate that I remind myself of the judicial task on sentencing.
In the present system of criminal justice, I must exercise my discretion as to what sentence should be imposed upon Mr Mahon by applying well identified principles of law to the facts which I find: R v MacDonell (NSWCCA, 8 December 1995, unreported) per Hunt CJ at CL at [1]-[2].
In the circumstances of this case, these principles of law require that I be satisfied beyond reasonable doubt of the facts upon which my sentence is based. Here, some of the facts surrounding the offence are agreed. Other facts, arising in the course of the sentencing process, and upon which Mr Mahon relies, need only to be proved on the balance of probabilities by him.
The appropriate approach to sentencing is to identify all of the factors that are relevant to sentencing, identify their significance with the particular circumstances of the offence and then to make a value judgment as to what is the appropriate sentence having regard to the purpose for which a sentence is to be imposed: Markarian v The Queen [2005] HCA 25; (2005) 228 CLR 357 at [51] per McHugh J; Muldrock v The Queen [2011] HCA 39; (2011) 244 CLR 120 at [26].
I will apply these principles in the course of this sentence.
[3]
The Relevant Legislation
The Parliament of NSW has determined the purposes for which a court may impose a sentence on an offender. Section 3A of the Crimes (Sentencing Procedure) Act 1999 provides that those purposes are:
"(a) to ensure that the offender is adequately punished for the offence,
(b) to prevent crime by deterring the offender and other persons from committing similar offences,
(c) to protect the community from the offender,
(d) to promote the rehabilitation of the offender,
(e) to make the offender accountable for his or her actions,
(f) to denounce the conduct of the offender,
(g) to recognise the harm done to the victim of the crime and the community."
Part 3 of the Crimes (Sentencing Procedure) Act sets out the relevant provisions that deal with sentencing procedures generally. Of particular importance are the terms of s 21A, which identify aggravating, and mitigating factors which a court must, or may, take into account. Those factors will need to be addressed in the course of this sentence. It is not mandatory that the sentence is increased or diminished by any one or more of these factors. As well, other provisions of Part 3 of the Crimes (Sentencing Procedure) Act have an impact on the process of sentencing in the case.
[4]
Principles of Sentencing
The courts have developed clear guidance for the exercise of the sentencing discretion by every judge. These common law principles are to be found in decided cases.
In summary, the common law principles include:
1. Proportionality - namely that the sentence should be proportionate to the gravity of the offence: Veen v The Queen (No 2) [1988] HCA 14; (1988) 164 CLR 465 at 472 per Mason CJ, Brennan, Dawson and Toohey JJ;
2. Parity - namely, that any difference between sentences imposed upon co-offenders for the same offence, ought not be such as to give rise to a justifiable sense of grievance, and to give the appearance that justice has not been done: Lowe v The Queen [1984] HCA 46; (1984) 154 CLR 606 at 617 per Dawson J, Gibbs CJ and Wilson J agreeing;
3. Totality - namely, that when a person stands for sentence for a number of offences, the Court must look at the totality of the criminal behaviour and determine what the appropriate sentence is for all of the offences: Mill v The Queen [1988] HCA 70; (1988) 166 CLR 59 per Wilson, Deane, Dawson, Toohey and Gaudron JJ;
4. Avoidance of double punishment - namely that a person should not be punished twice for the same conduct: Pearce v The Queen [1988] HCA 57 (1998) 194 CLR 610.
These principles have continuing relevance because s 21A(1) of the Crimes (Sentencing Procedure) Act preserves the entire body of judicially developed sentencing principles: R v Way [2004] NSWCCA 131; (2004) 60 NSWLR 168 at [56]-[57]: Muldrock at [18].
As well, factors established by the common law as affecting sentence, such as whether prison may be particularly burdensome, are also to be taken into account: Muldrock at [19].
I will need to bear in mind the legislation by which I am bound and the principles which the Courts have determined, when proceeding on this task of sentencing Mr Mahon.
[5]
The Facts
I find the facts of the matter, in accordance with the agreed Statement of Facts, which became an exhibit in the proceedings on sentence, to be as follows.
Mr Mahon was born in December 1969 and was, accordingly, 43 years of age at the time he killed Ms Grant.
Mr Mahon was in a de facto relationship with Ms Grant which had existed since mid-2011. Ms Grant was the mother of a 12 year old son from a previous relationship. She shared custody of her son with his father.
Ms Grant and Mr Mahon lived at a house in Warrigal Street, The Entrance. The house was located next door to the Greens Bowling Club. Occasionally, Ms Grant's son would stay with Mr Mahon and Ms Grant at the house.
Up until about November 2012, the relationship between Ms Grant and Mr Mahon appeared to be reasonable, and they were generally viewed as a happy couple. There were occasions upon which they argued.
On 23 November 2012, Mr Mahon attacked Ms Grant and assaulted her, causing actual bodily harm. Ms Grant sustained injuries to her left arm. The next morning, Mr Mahon also assaulted her son, who had intervened in an argument between Mr Mahon and Ms Grant.
As a result of these incidents, on 24 November 2012, an Apprehended Violence Order was made by the police. The interim order prevented Mr Mahon from attending the house at Warrigal Street. He was also prevented from contacting or approaching Ms Grant or her son. As well, arising out of this incident, Mr Mahon was charged with assault occasioning actual bodily harm with respect to Ms Grant, and common assault with respect to her son. He was granted bail upon the condition that he live with his long-time friends, Mr Wheeler and Ms Shaw.
On 20 December 2012, police attended the house at Warrigal Street. They found Mr Mahon at the house. He was arrested and charged with contravening the Apprehended Violence Order. On 21 December 2012, he was convicted at the Wyong Local Court for that offence. He was fined and ordered to pay costs.
By early January 2013, notwithstanding the terms of the Apprehended Violence Order, it appears that Mr Mahon had moved back in to the house at Warrigal Street and was residing with Ms Grant.
In the early hours of 11 January 2013, a friend of Ms Grant, Mr McGrath, was awoken by banging on the wall of his house just beneath his bedroom window. He asked who it was, and heard the deceased say "Jules". Mr McGrath spoke to her and she told him "Shannon's going off again".
[6]
Police Investigation
Police secured the crime scene at the house in Warrigal Street, and undertook extensive crime scene investigations.
After Mr Mahon was arrested and taken to The Entrance Police Station, a conversation occurred between Senior Constable Marshall and Mr Mahon. It was to the following effect:
"S/C Marshall: When did it happen Shannon?
Mr Mahon looked directly at S/C Marshall and said: Yesterday Arvo.
S/C Marshall: Did you two have a barny again?
Mr Mahon: Yeah just a normal barny like always.
S/C Marshall: Were you drinking? You two always fight when you are.
Mr Mahon: Yea, I was pissed.
S/C Marshall: How'd do you do it? What happened?
Mr Mahon: I don't really remember.
S/C Marshall: Ok. Were you at home?
Mr Mahon: Yeah but I don't really remember what happened."
A period of time was allowed by way of a recovery period as Mr Mahon had informed the Custody Manager that he had been consuming alcohol prior to his arrest.
Once recovered, Mr Mahon agreed to participate in an electronically recorded interview. During that interview, Mr Mahon said that he returned to live at the house at Warrigal Street soon after 21 December 2012, in breach of his bail and in breach of the conditions of his Apprehended Violence Order, because Ms Grant had told him she was having trouble coping with the anniversary of her mother's death.
Mr Mahon said that he last saw Ms Grant on the evening of 10 January 2013, when she left to go and visit some friends.
I am satisfied that this account was false because the argument which Ms Pagett, the neighbour, heard at about 4am on 11 January 2013, was an argument between Mr Mahon and Ms Grant.
Mr Mahon denied having any argument with the deceased, and denied any knowledge of Ms Grant's death. He could not explain why her body was found behind the bedhead. I am satisfied that these statements were also false.
On 13 January 2013, whilst in custody, Mr Mahon received a phone call from his friend, Ms Rachel Shaw. She asked him "What happened mate?". He said;
"I don't know, things got out of control, there is nothing I can do, what's happened, happened".
[7]
Expert Forensic Evidence
On 13 January 2013, Dr Vulvetic, a forensic pathologist, conducted a post-mortem examination on Ms Grant's body. She observed bruising to the neck, which indicated that significant pressure had been exerted most likely by manual strangulation. She formed the opinion that those injuries alone could have caused death.
She examined Ms Grant's scalp and determined that it showed extensive and multiple subcutaneous bruising in the frontal and right parietal area. She formed the view that this was indicative of blunt force trauma. She thought the degree of bruising was severe and that, as a consequence of such blunt force trauma, Ms Grant may have been rendered unconscious.
Dr Vulvetic formed the view that death was due to the combined result of the head and neck injuries, including the manual strangulation.
During the post-mortem examination, Dr Vulvetic observed an injury in the perineal area between the buttocks. She thought that it was a burn injury, inflicted post-mortem.
Professor Peter Maitz, who is the Burns Injury Specialist at Concord Hospital, and a leading expert in Australia in burn injuries, was consulted with respect to that injury. He formed the opinion that the burn injury extended over the left groin, labia majora and left upper thigh. He found that the burn injury was typical in appearance of a contact burn of full thickness. Dr Maitz concluded that the injury was possibly inflicted by an iron.
During the examination of the house at Warrigal Street, police located an iron in the room where the deceased was found. Forensic examination of the iron satisfies me that the iron was used by Mr Mahon whilst it was hot, and after Ms Grant had died, to inflict the full thickness burn injury to Ms Grant's perineal area.
[8]
Mr Mahon's Criminality
It is appropriate to make an assessment of the criminality involved in Mr Mahon's offence. This is to be assessed without reference to matters personal to Mr Mahon, and is to be assessed wholly by reference to the nature of the offending: Muldrock at [27].
The Crown submitted that I should assess the killing as falling in the mid-range of offences of this kind. Counsel for Mr Mahon, submitted that I would not be satisfied that Mr Mahon had an intention to kill Ms Grant, rather only that he intended to cause her grievous bodily harm. He submitted that this intention, together with the fact that the offence was not premeditated, and that it did not involve the use of any weapon, meant that I should not find that the offence was anything other than one falling below the mid-range of offences of this kind.
In my assessment, the criminality was very serious. It was above the mid-range of criminality for offences of this kind. Simply put, for no apparent reason other than feelings and emotions heightened by a verbal argument, Mr Mahon has murdered his de facto partner in her own home by brutally assaulting and strangling her. He has then inflicted a further gruesome burning injury on the deceased in the immediate post-mortem period. It was an injury inflicted to her genital area and reflects a high level of disrespect for Ms Grant's body, and represents the final act of indignity perpetrated upon her by the offender.
Mr Mahon then sought to conceal the body of the deceased behind the bedhead in a small space between the bedhead and a gyprock wall, into which the deceased had clearly been slammed.
He then went about his business, pretending that he had done nothing out of the ordinary and lying about the absence of Ms Grant to her friends, and to the police.
Ms Grant, although in her own home and protected by an Apprehended Violence Order, was no physical match for Mr Mahon. I would infer from the fact that she allowed him to return home to live with her that she trusted him and did not think that he would again violently assault her. There is no suggestion on the evidence that Ms Grant did anything which in any way provoked Mr Mahon to act as he did. There is no suggestion on the evidence that Mr Mahon was spurred into doing what he did by anything which Ms Grant did. Other than being involved in a verbal argument, the source of which is unknown to this Court, Ms Grant was a woman who had done nothing which could explain why she was subjected to such a brutal and vicious assault, by a man who, at the least, intended to cause her really serious physical injury.
[9]
Specific Statutory Considerations
As I have earlier said, it is necessary to identify the relevant aggravating and mitigating factors provided for by the legislation. An aggravating factor which is accounted for as being an element of the offence does not warrant any additional regard.
[10]
Mr Mahon's Record of Previous Convictions: s 21A(2)(d) Crimes (Sentencing Procedure) Act
Mr Mahon's past criminal record is not generally an extensive one. However, such convictions as are recorded relate to violence, and in particular, domestic violence.
In December 2002, Mr Mahon assaulted his then partner, Ms Elizabeth Ryan, by grabbing her with both hands, pushing her against a railing in the street, and then grabbing her by the throat. Mr Mahon was charged with, and convicted of, common assault for which he was placed on a bond pursuant to s 9 of the Crimes (Sentencing Procedure) Act for a period of 2 years.
In September 2004, Mr Mahon was charged with, and convicted of, the offence of assault occasioning actual bodily harm and the offence of common assault. Ms Ryan was again the victim in these assaults. Mr Mahon and Ms Ryan had become involved in a verbal domestic dispute, apparently as a result of Ms Ryan speaking with another male. Mr Mahon raised his left hand and slapped Ms Ryan on the right side of her face with the back of his hand. A short time later, Mr Mahon pushed Ms Ryan to the ground with both hands and with his right foot began kicking her left leg, causing her pain. Ms Ryan required treatment in hospital after this assault.
For these offences Mr Mahon was convicted and sentenced to a community service order which required him to serve a total of 150 hours of community service.
The next episode involved the events of November 2012 to which I have earlier made reference. As a consequence of these events Mr Mahon was convicted of assault occasioning actual bodily harm and common assault with respect to Ms Grant and her son.
Some more details of these most recent offences are necessary. On the evening of 23 November, Ms Grant's son was staying with her and Mr Mahon at the house in Warrigal Street. During the course of the evening, Mr Mahon got angry and told Ms Grant and her son to get out of the premises. He grabbed Ms Grant by her left bicep and dragged her out of the house. That evening she slept outside on the front porch. Her son slept in a tent in the backyard of the house.
The following morning, Mr Grant's son walked into the house having heard an argument between Mr Mahon and his mother. He saw Mr Mahon push Ms Grant to the face and ran over to try and protect her. As he did, Mr Mahon grabbed him around the neck using his right hand, lifted him off the ground and took him over to the oven, at one point dragging him along the ground. He then pushed Ms Grant's son into the oven, kneed him in the stomach and threw him onto the table. All that Ms Grant's son had tried to do was to protect his mother.
[11]
House of the Victim: s 21A(2)(eb) Crimes (Sentencing Procedure) Act
The statute describes the circumstance that the offence was committed in the home of the victim as an aggravating factor, because people are entitled to feel safe, in particular safe from being attacked, in their home. However, in this case, on all of the material that is available, it does appear that, notwithstanding the existence of the Apprehended Violence Order which prohibited Mr Mahon from being in the house occupied by Ms Grant, he was probably there with Ms Grant's consent. In those circumstances, I am not prepared to find that this is an aggravating factor: see DS v R [2012] NSWCCA 159 at [145] per Beazley JA, Harrison and McCallum JJ.
[12]
Offence Involves Gratuitous Cruelty: s 21A(2)(f) Crimes (Sentencing Procedure) Act
Here, I am satisfied that the infliction of the injury with the iron in the deceased's perineal area occurred in circumstances immediately proximate to the violent assault on the deceased, and probably just after the deceased had died. I am satisfied that it was a part of the facts and circumstances surrounding the offence. Both the Crown and counsel for Mr Mahon submitted that I was entitled to take the post mortem conduct into account as a matter relevant to the objective seriousness of the offence in accordance with the common law: Yeo v The Queen (2002) NSWSC 315 at [36]. In those circumstances, there is no need to, and I do not make any determination as to whether that conduct amounted to gratuitous cruelty, and I do not take this post-mortem conduct into account as an aggravating factor in the way provided for by the statute.
[13]
Conditional Liberty: s 21A(2)(j) Crimes (Sentencing Procedure) Act
At the time he committed this offence, Mr Mahon was on bail on the charges of assault occasioning actual bodily harm and common assault.
The terms of his bail required him to be of good behaviour while awaiting the disposition of those charges. His failure to comply with that condition of bail is an aggravating factor in this case of some significance.
[14]
The Offence was not part of a Planned or Organised Criminal Activity: s 21A(3)(b) Crimes (Sentencing Procedure) Act
This offence does not have any suggestion of a planned or organised criminal activity. On the contrary, the offence was committed in circumstances involving at least a domestic argument between the victim and the perpetrator. In the circumstances this has some, but not significant, mitigatory effect.
[15]
Likelihood of Re-offending: s 21A(3)(g), and Prospect of Rehabilitation: s 21A(3)(h) Crimes (Sentencing Procedure) Act
I am not satisfied on the evidence before me that Mr Mahon is unlikely to re-offend, nor am I satisfied that he has good prospects of rehabilitation. The report of Ms Kathryn Wakely, a forensic psychologist, was provided to the Court. It concludes that Mr Mahon has a long-term history of depression, anxiety and post-traumatic disorder, and has at times, abused alcohol and other illicit substances in an attempt to manage these symptoms. Ms Wakely recommends that Mr Mahon receive intensive treatment to address his mental health and substance abuse through participation in correctional based programs. Ms Wakely makes no assessment of his prospects of rehabilitation, nor his likelihood of reoffending.
In this context, having regard to Mr Mahon's history of past criminal convictions, particularly with respect to offences of violence occurring in a domestic circumstance, and particularly when combined with his tendency to drink alcohol to excess, I am not satisfied that at some time in the future Mr Mahon is unlikely to re-offend; nor that he has good prospects of rehabilitating himself. The evidence is simply inadequate to enable such a finding to be made.
As well, the basis upon which Ms Wakely's expert opinion depends, is the account given to her by Mr Mahon. That account was not supported by any sworn evidence given to the Court, nor any other contemporaneous version of events. It has very little weight.
[16]
Remorse: s 21(3)(i) Crimes (Sentencing Procedure) Act
If an offender shows remorse by providing evidence that he has accepted responsibility for his actions and by acknowledging any injury, loss or damage caused by his actions, or making reparations for such injury, loss and damage (or both), then this can be taken into account as a mitigating factor.
Mr Mahon did not give evidence before me. There is nothing in the agreed Statement of Facts which would enable any findings of remorse to be made.
I acknowledge that Mr Mahon has pleaded guilty and, to some degree, this plea can be regarded as demonstrating some remorse. However, the plea will be given full effect as an early plea of guilty. To take it into account in considering an expression of remorse would be to run the risk of double counting this as a mitigating factor.
Put simply, Mr Mahon has not satisfied me by any convincing evidence that he fully understands and appreciates which he has done, and that he is remorseful for the consequences of it.
[17]
Plea of Guilty
Where an offender has pleaded guilty to an offence, such as Mr Mahon has done in this case, the Court is obliged to take that into account in passing sentence for the offence: s 22 Crimes (Sentencing Procedure) Act.
A plea of guilty is relevant for a court to consider in determining the appropriate sentence to be imposed, because such a plea saves the community a considerable amount of time and money which contested committal hearings and trials would involve. It is a substantial facilitation of the course of justice. However, any lesser penalty imposed by reason of a plea of guilty must not be unreasonably disproportionate to the nature and circumstances of the offence.
It was submitted by counsel for Mr Mahon, and the Crown accepted, that Mr Mahon's plea of guilty had been entered at the first reasonably available opportunity. He is entitled to the maximum level of discount of 25 per cent in these circumstances.
[18]
Victim Impact Statements
The Court has received and admitted as an Exhibit a Victim Impact Statement from the son of Ms Grant. As well, the Court had read to it and admitted as an Exhibit, the Victim Impact Statement of Mr Greg Barrett, who is Ms Grant's brother.
I acknowledge, in accordance with s 28(3) Crimes (Sentencing Procedure) Act, the receipt of these two statements.
The impact of a mother's death on a young son, and on the balance of her family, is an obvious one. In the particular circumstances of this case, I am not satisfied that it is appropriate for me to consider and take into account for the determination of the punishment for the offence, the particular contents of either of these Victim Impact Statements as constituting an aspect of harm done to the community. Rather, I would prefer to rest my assessment of the consequences of the events in this case and for which I am sentencing the offender, upon the proposition that this is an example of a murder, and all killing is offensive to an ordered society.
[19]
Subjective Circumstances of Mr Mahon
Mr Mahon is now 45 years old. He was 43 when he killed Ms Grant. The only material before the Court about Mr Mahon's personal background, his relationship with Ms Grant and his personal circumstances surrounding the killing of Ms Grant, comes from the history which he gave Ms Wakely for the purpose of her report. The Crown submits that the Court should adopt a very considerable degree of caution in relying upon these statements, particularly where the offender has not given any evidence of the matters: R v Qutami [2001] NSWCCA 353 at [58]-[59] per Smart AJ, Spigelman CJ and Simpson J agreeing. Counsel for Mr Mahon accepts that this is the correct approach for the Court to follow. Although I will summarise the effect of these statements, I am only able to give them limited weight.
Mr Mahon apparently grew up as the middle of three children, and spent his formative years living with his parents and siblings. His mother stayed at home during his younger childhood, before gaining employment with the Picton Council. His father was employed as a truck driver, which meant he was often absent from home. Mr Mahon described his relationship with his father to Ms Wakely as 'distant'. He has not had contact with his father in many years.
Mr Mahon reported having been close to his mother throughout his childhood. He described witnessing physical altercations between his parents, which he considered was "a part of growing up as a kid". His parents separated around 15 years ago. He is now in contact with his mother.
Mr Mahon attended school until Year 10. After he left school, he worked in an archery store and as a tyre fitter. He then completed a spray painting apprenticeship, and worked as a bricklayer's labourer. During his time at work he witnessed a friend's death in the workplace. He was out of work for around eight months, after which he returned to the workforce and spending time working in tree lopping, scaffolding and with an aluminium window company.
At 20 years of age, he became involved in a relationship with a woman. Together they had three children, now aged 21, 19 and 18. The relationship ended when the youngest of the children was around 12 years of age.
In mid-2011, Mr Mahon and Ms Grant began a relationship. He and Ms Grant began residing together around 18 months prior to Ms Grant's death. Ms Grant's son would stay with the couple every second weekend and some weeknights.
[20]
General Deterrence
One of the matters to which a Court is obliged to have regard is the principle of general deterrence. This crime is one properly described as domestic violence. Domestic violence usually occurs in or around the home. Typically, the male partner will inflict physical violence upon his weaker and more vulnerable female partner. Such physical violence is often, but not always, accompanied by verbal abuse and other forms of abuse including controlling behaviour, bullying, verbal and physical threats and any conduct which denies or in any way prevents the female partner exercising her freedom to go about her ordinary life in the way she chooses. Domestic violence is antithetical to a democratic society where individual freedom is cherished; it undermines the principle of the gender equality
The importance of general deterrence in domestic violence cases has been repeatedly emphasised by courts in this State and all around Australia. That is because of the prevalence of violence by men against women in domestic relationships: R v Hamid [2006] NSWCCA 302; (2006) 164 A Crim R 179 at [64]ff.
All courts have a duty to ensure that domestic violence offences are adequately punished, and that sentences have a strong element of personal and general deterrence: R v Edigarov [2001] 125 A Crim R 551 at [11]. The sentence which I impose must also fulfil the purpose of denouncing Mr Mahon's conduct: s 3A(f) Crimes (Sentencing Procedure) Act; R v Dunn [2004] NSWCCA 41; (2004) 144 A Crim R 180 at [47].
[21]
An Appropriate Sentence
In considering the appropriate sentence to be imposed on Mr Mahon, I commence with the reminder that murder involves the criminal taking of a human life. It is a violation of the sanctity of human life which is a concept at the heart of a civilised community.
Ordinarily, a conviction for murder warrants a substantial sentence because the demands of punishment, and the deterrence of the broader community against similar conduct, are of significant importance. In Mr Mahon's case there is also an obvious need, having regard to his past history of violence in the domestic context, to ensure that any sentence which is imposed will act as a specific deterrent to him again engaging in such conduct.
I am not satisfied that I should make a finding of special circumstances as the law permits: s 44(2) Crimes (Sentencing Procedure) Act. Mr Mahon submitted that special circumstances existed. However, Mr Mahon's past history of offending, including the fact that he has spent a previous period in custody prior to the commencement of this offence, and his guarded prospects of rehabilitation, all tell against the need for a finding of special circumstances.
I have discussed all of the facts which are relevant to the decision, and it is now necessary to make a value judgment as to what is the appropriate sentence.
This was a very serious offence involving the killing of a woman in her own home in a way which was brutal and cruel. The killing was committed by her de facto partner with a past history of committing assaults in the domestic context. Having murdered Ms Grant, he then subjected her body to further injury, attempted to hide it and then lied about what had happened.
There is nothing which adequately explains or justifies the conduct. It would be inappropriate to speculate about why Mr Mahon did what he did, but I am satisfied that an argument in the domestic circumstance, perhaps in the context of alcohol being consumed, must have had a role to play in what happened. That said, the Court can only proceed to impose a sentence for what is a serious and largely, though not entirely, unexplained offence.
Any sentence which is imposed is mitigated only by his plea of guilty and the substantial facilitation of the course of justice which that involves.
I determine the appropriate sentence to be one of 30 years imprisonment. However, Mr Mahon is entitled to be given an appropriate discount for the fact that he has pleaded guilty to his offence. In the circumstances here relevant that discount, I am satisfied, should be 25 per cent. Accordingly, the total appropriate sentence is one of 22 years and 6 months imprisonment. Of that sentence, I determine that Mr Mahon must spend 16 years and 10 months in jail before being eligible for parole.
[22]
Commencement Date
In light of his convictions for the offences of assault occasioning actual bodily harm and common assault in the Wyong Local Court, and the sentences of imprisonment which were imposed there to commence on 12 January 2013, and to continue through to 11 August 2013, I determine that it is appropriate for this offence to commence 6 months after the commencement of the previous term of imprisonment. Accordingly, the appropriate date for commencement of the sentence for this offence is 12 July 2013.
[23]
Offence of Serious Personal Violence
I am required to warn Mr Mahon, which I now do, of the existence of the Crimes (High Risk Offenders) Act 2006, and the fact that that Act applies to the offence of which he has been convicted, and for which he is to be sentenced. At some future point in time an application may be made that, notwithstanding the completion of his sentence, he nevertheless ought be detained in ongoing custody or else ought be the subject of an extended supervision order, impacting upon his liberty.
[24]
Sentence
Mr Mahon, I sentence you to the following term of imprisonment:
1. A non-parole period of 16 years and 10 months commencing on 12 July 2013 and concluding on 11 May 2030.
2. A balance of term of 5 years and 8 months commencing on 12 May 2030 and concluding on 11 January 2036.
3. You will not be eligible to be released before the expiry of your non-parole period.
[25]
DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.
Decision last updated: 09 February 2015
Total sentence of imprisonment of 22 years and 6 months, comprising a non-parole period of 16 years and 10 months commencing 12 July 2013 and a balance term of 5 years and 8 months to conclude on 11 January 2036; offender not eligible for release before expiry of non-parole period.
At approximately 2.35am on that day, CCTV footage from the Greens Bowling Club captured Ms Grant walking back towards her house at Warrigal Street.
At about 4am on that day, 11 January 2013, a neighbour, Ms Pagett, heard an argument between a male and female at the house in Warrigal Street. I am satisfied that this was an argument between Mr Mahon and Ms Grant.
This occasion was the last one upon which anybody other than Mr Mahon saw or heard Ms Grant prior to her death.
After that time there were a number of sightings of the offender. At about 5.30pm on 11 January 2013, Mr Mahon went to Mr Wheeler's house in Blue Bay. He was drunk, visibly upset, blubbering and rambling. Although Mr Wheeler could not clearly understand what was being said to him by Mr Mahon, he thought he said "I have killed her". Mr Wheeler dispatched Mr Mahon, telling him to sober up and that he would talk to him the following morning. There was a later telephone call between Mr Wheeler and Mr Mahon in which Mr Mahon sounded less intoxicated and was not rambling as much, during which he was told that he could speak with Mr Wheeler in the morning.
At about 8.30pm on 11 January 2013, Mr Mahon rang another friend, Mr Van Praag and asked if he had seen the deceased. When that answer was negative, Mr Mahon told Mr Van Praag, that the deceased had left home about midnight on the evening before and that he had not seen her since.
I am satisfied that this was a deliberate and intentional lie, told by Mr Mahon, to conceal his crime.
On the following morning, 12 January 2013, Mr Wheeler saw Mr Mahon in Warrigal Street. They had a conversation in which Mr Mahon kept repeating "I don't know what to do. I don't know what I'm going to do".
Finally, after being urged by Mr Wheeler to hand himself in to the police, Mr Mahon said;
"I don't know what to do. I don't know what to do. I'm gunna go and get a schooner and a couple of beers and I might see you later."
Mr Mahon went to the Lakes Hotel.
Shortly after this conversation with Mr Mahon, Mr Wheeler attended at The Entrance Police Station and reported to the police that he had concerns about the well-being and safety of Ms Grant.
As a consequence of that report, police attended at the house in Warrigal Street. There was no-one home. They forced entry into the premises. They searched the house. When looking in the main bedroom, the police, using a torch, looked behind the bedhead of the bed and found the body of Ms Grant in a small space on the floor jammed between the bedframe and the wall. She was lying face down and was naked from the waist down. Near the top of the bedhead, a large hole was visible in the gyprock wall directly above where Ms Grant lay on the floor. A light stand at the head of the bed had been smashed, and shards of glass from the light stand were resting on top of the deceased's body.
At about 10.20am that morning, police attended at the Lakes Hotel, and identified the offender, Mr Mahon, in a rear beer garden. He was arrested and cautioned. He was taken to the Police Station.
And the assault was a very brutal one. Two of the gyprock walls of the bedroom where Ms Grant was found, show significant damage in a way consistent with Ms Grant having been slammed most forcefully into them. At some stage during the assault, probably towards the end, Mr Mahon has strangled Ms Grant with his bare hands. A standard lamp and lampshade have been smashed with shards of glass found on top of Ms Grant's body. It appears that after the post-mortem assault that the bed was moved back into a position where the bed head was as near as possible to its original position near the wall, notwithstanding the presence of the body of the deceased on the floor between it and the wall.
As best as can be determined, in assessing the seriousness of the criminality involved in the objective circumstances of this offence, it seems to me that the only basis upon which the conduct can be found to have occurred, is in the context of the escalation of a verbal argument between Mr Mahon and Ms Grant, in circumstances where Mr Mahon had been drinking extensively. There is no doubt that Ms Grant had also been drinking alcohol. This may have contributed to the existence of the argument, but there is simply no evidence at all, and I am not persuaded that I ought to find, that Ms Grant's conduct was in any way responsible for what occurred to her.
This was an unprovoked assault in Ms Grant's home upon her by her de facto partner, in circumstances where he was prohibited by an order of the Court from being present in that location and during a time at which he was on bail for committing an offence of personal violence towards Ms Grant.
I am satisfied that the facts, matters and circumstances of and surrounding this crime are very serious and place it above the mid-range of objective criminality for offences of this kind.
For those offences, Mr Mahon was convicted and sentenced to a term of imprisonment, commencing on 12 January 2013 and expiring on 11 August 2013.
As I have said, as a result of these incidents, an Apprehended Violence Order was made against Mr Mahon, which he then promptly contravened in December 2012 and for which he was convicted, fined and ordered to pay costs.
These previous convictions include convictions for serious personal violence offences and accordingly, are particularly relevant here as this offence involves him being sentenced for a serious personal violence offence. I will take this into account as an aggravating factor. But, Mr Mahon is not being punished again for the criminality involved in these offences: Veen (No 2) [1988] HCA 14; (1988) 164 CLR 465.
I have earlier referred to the conclusions of Ms Wakely about Mr Mahon's mental health, and there is no need to repeat them. I have taken them into account to the extent which I can. Ms Wakely suggests that:
"…the combination of pre-existing mental health difficulties, emerging paranoia stemming from numerous incidences having taken place in the year before the offence, some underlying unhelpful attitudes relating to physical violence, paired with serious alcohol abuse are each likely to have contributed to the current circumstances."
To the extent that this opinion offers an explanation for what happened, I will have regard to it, but since it largely derives from the history given by Mr Mahon, I give it only limited weight.