Nine weeks after the fatal shots were fired, police are now prepared to label the fatal assault a religiously-motivated terrorist attack.
In December last year, Queensland police officers Constable Matthew Arnold and Constable Rachel McCrow were murdered on a Wieambilla property, more than 300 kilometres west of Brisbane, by a trio of conspiracy theorists.
Nathaniel, Gareth and Stacey Train were later killed in a gunfight later that night with specialist police.
Deputy Police Commissioner Tracy Linford said investigators had taken more than 190 statements and combed through the lives of the Train family.
She said although the investigation was ongoing, police did not believe the attack was random or spontaneous, and police had been deliberately targeted.
"Our assessment has concluded that Nathaniel, Gareth and Stacey Train, acted as an autonomous cell and executed a religiously motivated terrorist attack," Ms Linford said.
"The Train family members subscribe to what we would call a broad Christian fundamentalist belief system known as premillennialism - it's a belief system that comes from Christian theology."
Police believe the trio acted alone, and no other people were involved in the attack.
Police have also confirmed the assault was meticulously planned and the family was prepared to defend against police.
The trio camouflage hides, wore camouflaged clothing and erected multiple barriers around the property.
Police also seized sex firearms, compound bows and arrows, and knives from the Wieambilla property.
Madelyn Train, the biological daughter of Nathaniel and Stacey, has given a number of interviews to insist there had been no warning signs before the fatal shootout.
However, she admitted Gareth did hold extreme views and was a military enthusiast.
"It was like he was doing this weird project on COVID and the end of the world but also religiously. He believes in the apocalypse," she said.
Ms Train said she would often try to steer her uncle to other subjects when conversations took a dark turn.
She said she knew Nathaniel owned guns and that Stacey and Gary had a gun safe and weapon licences.
"But mum didn't like guns," Ms Train said in the televised interview.
32°C