Background
John Jamie Tozer pleaded guilty to manslaughter arising from the death of Ricky Ciano, which occurred between 11 and 13 February 2017. Tozer’s liability was as an accessory at the fact: he supplied cocaine and heroin (a “speedball”) to his co-offender Daniel Bushell, who intravenously injected the mixture into the deceased. The incident took place at a clandestine drug laboratory in a remote location where all three men were engaged in manufacturing prohibited drugs. The sentencing judge found on the balance of probabilities that the deceased consented to the injection. After the injection Ciano died, and neither Tozer nor anyone on his behalf sought medical assistance. Tozer then directed another person to move the body away from the laboratory, concealed the death from Ciano’s wife, and continued participating in the drug manufacturing enterprise.
The case had a protracted history. Tozer was originally charged with murder; his early offer to plead guilty to manslaughter was rejected by the Crown, and a joint murder trial commenced in 2023 before being vacated against Tozer due to inadequate prosecution disclosure concerning an informer witness. In the intervening period, Tozer was sentenced in the District Court for two counts of supplying a large commercial quantity of a prohibited drug and one count of manufacturing a large commercial quantity of a prohibited drug, receiving nine years’ imprisonment with a non-parole period of five years and nine months (expiring 6 December 2023). On 12 February 2025 the Crown accepted his guilty plea to manslaughter in full satisfaction of the murder indictment.
On 24 April 2025, Weinstein J sentenced Tozer to five years and six months’ imprisonment — reflecting a 25% discount for the utilitarian value of the guilty plea — commencing on 6 December 2023 (the expiry date of the non-parole period of the drug sentence) and expiring 5 June 2029, with a non-parole period of two years and nine months expiring 5 September 2026. The effect was to make the manslaughter sentence cumulative on the non-parole period of the earlier drug sentence, producing a total effective sentence of eleven years and three months with a combined non-parole period of eight years and six months. Tozer sought leave to appeal that sentence to the Court of Criminal Appeal.
The Court’s Holding
The Court (Dhanji J, with N Adams CJ at CL and Richardson J agreeing) granted leave to appeal but dismissed the appeal on both grounds. On the first ground — that the sentencing judge erred by not imposing a partially concurrent sentence — the Court held that while the manslaughter was committed in the same context as the drug offences (at the same clandestine laboratory, during the same period of offending), the underlying criminality was discrete and of a quite different character. The contextual overlap did not mandate any degree of concurrency. The Court further noted that Tozer had continued his involvement in the drug enterprise after witnessing firsthand the lethal capacity of prohibited drugs, which counted against him and reinforced the distinct nature of the two bodies of offending. The Court also clarified that, because Tozer’s complaint identified no specific error in the sentencing judge’s reasoning but only challenged the result of the discretion exercised, the substance of ground one was really a complaint of manifest excess.
On the second ground — manifest excess — the Court accepted that this was not the worst case of manslaughter: the deceased had consented to the injection and Tozer had a reasonable subjective case, including a disadvantaged childhood, serious physical and sexual abuse, complex PTSD, and severe polysubstance use disorder, which the sentencing judge had found reduced his moral culpability. Nevertheless, the Court held that the sentence of five years and six months was not unreasonable or plainly unjust when viewed in isolation. The implied starting point of seven years and four months (before the plea discount) was not excessive given the remote location, the failure to summon any medical assistance, the concealment of the death, and the fact that the offence involved criminal responsibility for the death of another person. Viewed in combination with the drug sentence, the total effective sentence was also not manifestly excessive: the additional imprisonment it imposed directly reflected the additional and distinct criminality of the manslaughter, and the favourable non-parole to total ratio provided some mitigation of the cumulative impact.
Key Takeaways
- Offences sharing a temporal and physical context are not thereby sufficiently “related” to mandate concurrent or partially concurrent sentences; what matters is whether the underlying criminality of one offence is capable of encompassing the criminality of the other.
- Where an appellant’s true complaint about a commencement date is not a discrete error of principle but the overall result of the sentencing discretion, the Court will treat the ground as one of manifest excess and apply the demanding House v The King standard.
- An offender’s consent to the dangerous act that kills them does not eliminate the seriousness of the offence; the materialisation of the lethal risk is a central factor in assessing objective gravity for manslaughter by unlawful and dangerous act.
- When assessing the totality of cumulative sentences, courts must recognise that the severity of a sentence increases at a non-linear rate as it grows longer, but additional criminality that is genuinely distinct will justify additional imprisonment even where the aggregate is substantial.
Why It Matters
This decision clarifies the limits of the totality principle where an offender faces sentences for crimes that overlap in time and setting but involve materially different forms of criminality. Defence practitioners and sentencing judges will note that contextual proximity alone — such as offences occurring at the same premises during the same criminal enterprise — does not compel any degree of concurrency; the court must look to whether the criminality of one offence genuinely absorbs or comprehends that of the other.
The case also illustrates the difficulties inherent in sentencing for manslaughter, an offence that encompasses an exceptionally wide range of culpability. The Court’s affirmation of the sentence, notwithstanding the deceased’s consent to the injection and Tozer’s significant background of deprivation and mental illness, signals that post-offence conduct — particularly failing to seek medical assistance and actively concealing a death — can meaningfully aggravate objective seriousness and limit the weight given to otherwise mitigating subjective factors.