The shocking deaths of two police officers ambushed at a rural property have left a "terrible void" that will never be filled, their families say.
However, they will "persevere through our pain" at an inquest into the fatal shootings to honour their memory, calling for any reforms to be introduced immediately.
Constables Matthew Arnold and Rachel McCrow were shot in cold blood by Nathaniel, Gareth and Stacey Train at the Queensland property on December 12, 2022.
Almost two years later, the officers' families spoke for the first time about the tragedy ahead of the inquest into the fatal shooting of six people at Wieambilla, west of Brisbane.
"Our collective heart remains broken beyond repair," said Judy McCrow, the mother of Const McCrow, on behalf of the fallen officers' families outside the Brisbane Coroners Court on Monday.
"We have been robbed of a beautiful, caring daughter and son who loved life and had so many adventures ahead of them."
Neighbour Alan Dare was also shot dead when he came to investigate before the Trains were killed in a gunfight with specialist police later that night at the property.
Ms McCrow said the families' thoughts were also with Mr Dare.
"As hard as it is to stand here, we know how important it is. That is because we don't want the loss of Rachel and Matthew to be in vain," she said.
"We must persevere through our pain, to honour their memory and strive for a safer tomorrow.
"We want everyone to remember Rachel and Matthew and their ultimate sacrifice."
She was joined by Const McCrow's sister Samantha McCrow and Const Arnold's father, Terry Arnold, mother Sue Arnold and sister Hayley Arnold.
"What unfolded in Wieambilla on December 12, 2022 should never have happened," Ms McCrow said.
"No police officer committed to their job, their colleagues, and their community should die under such horrible, brutal circumstances.
"While the terrible void in our lives will never be filled, we hope any reforms put forward by the coroner will prevent a tragedy like this happening again and other families experiencing our heartbreak."
Ms McCrow hoped the inquest uncovered what happened "that horrific day".
"Any change to policing processes, procedures or policies to reduce the likelihood of loss of life occurring in similar circumstances must be introduced immediately," she said.
"We pose this question to authorities: Could a national weapons and ammunition register, drones and satellite-based communication strategies reduce the current risk?"
Queensland Police Commissioner Steve Gollschewski said they owed it to the fallen officers to implement whatever they learned from the inquest.
"I think we're open to learning," he said on Monday.
"You'll see our commitment to the memory of Matthew and Rachel to make sure that whatever we learn from this we will put into play."
A national firearms register is set to be online by 2028 and a new Queensland weapons licensing management system by late 2025.
"This is a tragedy that broke the hearts of every single Queenslander," Police Minister Mark Ryan said of the shootings.