R v Edwards

The appellant, the Director of Public Prosecutions, appealed against sentences imposed by the District Court on the respondent. The respondent had been sentenced to a total of four years, 10 months, and 21 days imprisonment, with a non-parole period of three years and six months, for offences including aggravated causing death by dangerous driving, aggravated serious criminal trespass, aggravated assault causing harm, being unlawfully on premises, and damaging a motor vehicle. The appellant argued that these sentences were unduly lenient and should be increased.

The central legal issues before the Full Court of the Supreme Court of South Australia were whether the sentences imposed by the District Court were so manifestly inadequate as to warrant appellate intervention, and if so, what increased sentences should be substituted. This involved considering the appropriate weight to be given to the respondent's guilty pleas, his subsequent development of post-traumatic stress disorder and substance abuse, and the specific circumstances of the dangerous driving offence, including the presence of THC in his blood.

The Court considered the evidence regarding the presence of THC in the respondent's blood, noting that while THC levels do not precisely correlate with impairment in the same way as alcohol, a concentration of 5 mcg/L or above generally indicates recent cannabis use. The Court found it highly unlikely that the respondent's THC level of 7 mcg/L, detected approximately four hours after the collision, could be explained by use eight hours prior, suggesting he was likely under the influence of cannabis at the time of the crash. The Court acknowledged the known effects of cannabis on driving ability, including impaired concentration, coordination, and decision-making, while also noting a potential decrease in risk-taking behaviour compared to alcohol. The Court ultimately found that the sentencing judge had erred in his assessment of the objective seriousness of the dangerous driving offence and the impact of the respondent's drug use.

The Court allowed the appeal, quashed the sentences imposed by the District Court, and resentenced the respondent. The new sentence for aggravated causing death by dangerous driving was imprisonment for four years, with a non-parole period of three years. The sentences for the other offences were also adjusted, resulting in a total head sentence of five years, 10 months, and 21 days imprisonment, with a non-parole period of four years and six months.