Peter Jackson's "whole world" was ripped from him in November 2019 when his two-year-old daughter Darcey, and her little sister Chloe-Ann died.
WARNING: This story contains content that readers may find distressing.
The children were left alone inside a car outside their Waterford West home for nine hours while the internal temperature soared over 60 degrees Celsius.
Police were quick to arrest their mother, Kerri-Ann Conley, 30, and charged her with two counts of murder.
It is the most serious offence available and is normally reserved for people who intentionally kill and comes with a hefty mandatory penalty – life in prison.
This was possible due to a legislative change in Queensland which had only come into effect weeks before the girl's deaths.
Conley became the first person in the state to be charged with murder under an expanded definition, which now considers whether a killer has shown reckless indifference to human life.
But before the case could even get to a jury, Mr Jackson would be told murder was "too hard to prove" leaving the father feeling defeated and cheated by the justice system.
What is reckless indifference?
In May 2019, the state government passed several reforms which centred around tougher penalties for child killers.
This included expanding the definition of murder, which would generally require proof a person had intended to unlawfully kill or at least cause grievous bodily harm.
These changes came after a string of horrific court cases where the sentences for people convicted were perceived as light, triggering outrage from the community.
Around the same time, the Queensland Sentencing Advisory Council (QSAC) validated this public criticism.
It released a report which found the jail terms handed to people who were guilty of the manslaughter of a child were inadequate and did not reflect community expectations.
At the time, when introducing the new legislation, Premier Annastacia Palaszczuk was firm.
"We want to see stronger sentences imposed when people take the lives of our most vulnerable," she said.
In response to the new murder provision, the then attorney-general Yvette D'Ath said the change would mean prosecutors "won't have to prove intention to kill" anymore.
"You'll just have to show that they've had reckless indifference for that human life and there was a probability that that child would die," she said at the time.
It was supposed to capture people who showed a higher form of negligence than what was normally considered in manslaughter cases.
What happened with Conley's case?
Conley would have been the first person to have the broadened charge tested in court if her case had gone before a jury.
In June 2021 she was ordered to stand trial for murder after a committal hearing to determine if there was enough evidence, and up until this point, she was still planning to defend the charges.
But it was not long after her matter moved to the Supreme Court, Mr Jackson said he was told by the people who decide what cases should go to trial or not, the Department of Public Prosecutions (DPP), that lesser charges had been negotiated.
"I was given that information, that it was too hard to prove murder," he said.
"I couldn't see how, but that's what I was told."
Mr Jackson said he felt let down by the news but had to accept it.
"Obviously I wasn't happy about the manslaughter — but I couldn't argue," he said.
"That's the justice system for you."
During sentencing submissions last week, Mr Jackson, the media and the public, heard detailed information about the facts of the case, some of which had never been revealed before.
The court was told Conley, who was a drug addict, had made a "deliberate decision" to leave her children in the car at 4am after spending the night socialising with friends.
This was not the first time she had left them in the car alone, telling police after her arrest she did not like waking them when they were sleeping because they were too hard to settle.
After heading inside, she continued to use her phone for almost two hours, by which point the sun would have already been up.
Conley then fell asleep after "crashing out" from taking the drug ice the day before.
She did not wake up for several hours and by that stage her children were already dead.
The temperature had climbed past 30C that day, the estimated temperature inside the car was more than double that.
Conley pulled her girls from the hot car one by one, but before calling paramedics she was captured on CCTV disposing of drug paraphernalia.
This act was described by the prosecution as her having a "primal instinct" to protect herself over her children.
The sentencing judge commented that Conley ought to have known the serious risks of leaving her daughters restrained with no ventilation, and her negligence extended to her not bothering to get them out while still awake.
Conley eventually called triple-0 as well as Mr Jackson, who arrived first.
He tried desperately to revive the girls, who were limp and covered in burn blisters, but it was too late.
This memory of them haunts Mr Jackson every day.
'I still think it should be murder'
After learning of Conley's repeated negligent actions in court, Mr Jackson said it was "unbelievable" a downgraded plea was accepted.
"I still think it should be murder," he said.
"I do believe the charges should have stuck.
"These were defenceless children."
Conley was handed a nine-year sentence for manslaughter and will be eligible to apply for parole in November next year after serving five years in custody.
If she had been convicted of the original double murder, under Queensland sentencing legislation she would have been forced to serve a mandatory non-parole period of 30 years.
This is tough for Mr Jackson to swallow.
"I don't think it's fair," he said.
"She should have got the 30 years."
It was not disclosed during Conley's sentencing why a guilty plea of manslaughter was accepted, but her defence lawyer said "the [murder] charge was misconceived from the very start".
The ABC asked the DPP to provide those reasons, and confirm they told Mr Jackson it was due to not being able to prove murder.
It declined to answer, citing Conley was still within her mandatory appeal period.
Attorney-General Shannon Fentiman was also asked about the matter and told the ABC the decision to accept the plea of a lesser charge "entirely sits with the director of public prosecutions".
"They've obviously made an assessment of the case given that the defendant was happy to plead," she said.
"It really depends on the circumstance of the case, the DPP are best placed to make those decisions with all of the evidence before them.
"We're really proud of our track record on strengthening the laws when it comes to murder," she said.
When asked if she thought the legislation was not being utilised when it could be, Ms Fentiman said Queensland was "one of the only jurisdictions that have those strong provisions".
"The provisions have only been in place for a very short time … The DPP and the legal community were heavily consulted in the drafting of those laws they are very tough laws," she said.
Ms Fentiman said manslaughter was still an "incredibly serious charge".
"We've seen a very serious penalty handed down," she said.
Law proving 'ineffective'
Criminal lawyer and former president of the Queensland Law Society Bill Potts said the technicalities of the charge might have led a jury to find Conley guilty of manslaughter in the alternative to murder anyway.
Because of this, Mr Potts said he did not believe it was a "sign of weakness" by the DPP to accept a downgraded charge.
"It's not only a saving in court time and money and there's a saving upon witnesses who have to relive the horror of the matter," he said.
"But it's also a sign of humanity … because when you start to introduce concepts of negligence to a jury it's a slippery slope — jurors may well find people not guilty."
"Or they may have in any case opted for the ultimate verdict, which is manslaughter."
Mr Potts said the DPP would have had to balance "all of the features" of the matter, but he thinks the main issue comes down to the mandatory "one-size-fits-all" sentence for murder.
"[The DPP] must have thought that it was at least strongly likely that the jury may find her not guilty entirely, in which case no penalty would have been imposed," he said.
"The simple reality is murder is very hard to prove, because juries know that the only penalty they're going to get is life imprisonment."
Mr Potts said there are "very real practical concerns" about the provision of reckless indifference, and it was now being demonstrated "the law itself is ineffective".
"Government's often respond to bad cases by bringing in laws, which either don't get used or are effectively stillborn," he said.
Mr Potts said murder "should be reserved for the most extreme of cases" and changes to sentencing legislation would be more beneficial.
"Failure of parenting is not necessarily something which deserves or indeed calls for a life sentence," he said.
"That's why I think we should have a sliding scale so that judges can balance each of the circumstances.
"If judicial officers had a discretion to impose penalties which reflect the seriousness of the offence rather than just one sentence imposed, then I think we would see this charge prosecuted more often."
A number of people have since been charged with murder under the same provision who have similar circumstances to Conley's case, but many are still waiting to be prosecuted.
Mr Jackson said although the court process had "taken a toll" on him, he was hopeful the families of other children killed might still have a different outcome than he did.
"In future I'd like to see the full life sentence," he said.
"It needs to happen … [Manslaughter] is just not good enough."
