An "extraordinary" High Court appeal has been launched over a teenager who fatally stabbed a mother in a brutal Boxing Day home invasion.
Queensland's Attorney-General has applied to the court to appeal a decision to reduce the juvenile's sentence for a horror attack that "rocked the state" and sparked controversial law reforms.
"For an attorney-general of a state to lodge an application for special appeal to the High Court is extraordinary but I don't back away from that," Attorney-General Deb Frecklington told reporters on Monday.
The boy, who cannot be named as he was aged 17 at the time of the murder, stabbed Emma Lovell after he broke into her family's house north of Brisbane about 11.30pm on Boxing Day in 2022.
His sentence was reduced by almost 18 months following a successful appeal in August, leaving Ms Lovell's husband Lee and family feeling "broken".
The offender would be released before Ms Lovell's two daughters "even get to walk down the aisle", Ms Frecklington said.
"I have spoken to Lee Lovell and I have reiterated the Crisafulli government's commitment to do all we can to ensure the murderer who took Emma's life is held accountable," she said.
The teen was initially set to serve nine years and nine months before being released under supervision after pleading guilty to murder.
His successful appeal reduced it to eight years and four months.
Ms Frecklington said the teen's successful appeal was a result of the previous Labor government's "weak laws".
The home invasion was a catalyst for "adult crime, adult time" changes in Queensland law under the Liberal National government after it won the 2024 state election.
The new legislation allows for youth offenders to face a mandatory life sentence for serious offences such as murder, with a minimum of 20 years before parole.
"The challenge we face is this offending happened under Labor's weak laws - and now ... this teenager could be out of detention even sooner," Ms Frecklington said.
Ms Lovell was fatally stabbed during a struggle on her front lawn, with her husband Lee also wounded.
Justice Tom Sullivan in May 2024 sentenced the teen, then aged 19, to a maximum of 14 years, with a requirement to serve 70 per cent of that time in detention, after he found the crime to be "particularly heinous".
The Court of Appeal in August allowed the teen's appeal against the length of his sentence, with two of the three judges agreeing it was "manifestly excessive".
Justice David Boddice found the 14-year sentence should stand but reduced the detention period to 60 per cent of the term.
He cited the teen's guilty plea, "genuine remorse and prospects of rehabilitation" as special circumstances justifying his release from detention after serving less than the statutory 70 per cent.
The teen has five years left to serve in detention after 500 days of pre-sentence custody in May 2024 were recognised as time served.
The state government owed it to the Lovell family to pursue the appeal option, Queensland Premier David Crisafulli said.
"This is a tragedy that rocked the state and it impacted a brave Queenslander and his two girls," he told reporters.
