A teenage boy who killed an "innocent young couple" and their unborn baby in a hit-and-run in south-east Queensland on Australia Day last year has been jailed for 10 years, but will only serve 60 per cent of the sentence.
The now 18-year-old was under the influence of cannabis and alcohol when he sped through a red light and collided with a tow truck, causing the stolen 4WD to roll.
Katherine Leadbetter, who was 24 weeks pregnant, and her partner Matthew Field were walking their dogs in Alexandra Hills, east of Brisbane, when the out-of-control car slammed into them at the intersection.
The pair died instantly.
The teenager, who was uninjured, fled the scene but was later caught and detained by a resident after he tried to steal another car nearby.
After his arrest, he was charged with two counts of murder, but he has since pleaded guilty to the lesser charges of manslaughter.
He has also admitted to several other charges including driving offences.
Due to being 17 years old when he offended, he is being dealt with as a juvenile and cannot be identified.
Drugs and alcohol on a 'daily basis'
The court heard the teen had been consuming drugs and alcohol on a daily basis at the time and had since expressed remorse for his conduct, acknowledging "what he has taken" from the families.
He has spent almost 18 months in detention, and in that time has completed year 12 and obtained other qualifications, as well as engaged with mental health and alcohol rehabilitation services, the court heard.
When handing down his sentence, Justice Martin Burns told the court the consequences of the teenager's "particularly heinous" offending led to "the heartbreaking death of an innocent young couple" but accepted he had no intention to kill them.
"The facts are indisputable," he said.
"This is a case of gross negligence and must surely fall within the worst category of such cases."
After considering the teen’s early guilty plea, his steps toward rehabilitation, and "genuine remorse and shame", Justice Burns ordered he should be released from custody after serving six years.
Justice Burns told the teen there was no sentence he could serve which would ever be adequate for the families who would suffer with "irremediable grief and sorrow".
During a sentencing hearing in Brisbane on Tuesday, family members detailed their heartache over losing the "beautiful couple", with several people reading victim impact statements to the Supreme Court.
Relatives of Mr Field and Ms Leadbetter left the courtroom when distressing footage showing the teen's erratic and dangerous driving in the 20 minutes leading up to the crash was played, as well as the moment of impact from a number of angles.
Crown Prosecutor Todd Fuller told the court the teen's "reckless" and "dangerous" driving had been to "satisfy his own selfish needs".
"And putting other road users and others at risk — that risk on this occasion came to pass with respect to Mr Field and Ms Leadbetter," he said.