Nguyen v The Queen

The appeal concerned the sentence imposed on the appellant, who had pleaded guilty to trafficking in a large commercial quantity of a controlled drug, possessing a controlled drug on two occasions, and possessing prescribed equipment, contrary to the Controlled Substances Act 1984 (SA). The sentencing judge had imposed a head sentence of three years, two months and five days, with a non-parole period of two years, six months and 17 days, taking into account a guilty plea and the appellant's status as a serious repeat offender. The Court of Appeal considered the sentencing judge's application of sentencing principles in light of the appellant's diagnosed intellectual disability, significant cognitive impairment, and multiple mental health disorders.

The legal issues before the Court of Appeal were whether the sentencing judge erred in applying the principles relevant to the appellant's intellectual disability and mental impairment, whether the judge erred in applying section 54(2) of the Sentencing Act 2017 (SA), and whether the imposed sentence was manifestly excessive. The appellant's intellectual disability was described as being in the 'Intellectual Disability' range with an IQ above 70, placing him in the 0.01 percentile for age-equivalent cognitive ability, and his psychologist considered him one of the most extreme cases of poor cognitive ability assessed.

The Court of Appeal, per Bleby JA, found that the sentencing judge had not adequately grappled with how the appellant's intellectual disability and mental impairments might affect the principles of personal and general deterrence, nor how the sentence might weigh more heavily on him compared to an offender without such impairments. The Court also determined that the sentencing judge had erroneously foreclosed an inquiry into whether the appellant's exceptional personal circumstances, as identified by his psychologist, met the statutory description in s 54(2) by describing them as 'regularly, routinely or commonly encountered by the courts'. Consequently, the appeal was allowed, and the appellant was resentenced to a head sentence of two years, four months and 16 days, with a non-parole period of one year and six months, backdated to commence on 23 November 2020.