Killer couple Gareth and Stacey Train uploaded their message in a grainy video to a now-deleted YouTube account about 7.40pm on Monday, hours after three people had been shot dead.
The sound of a police helicopter can be heard in the background, while the couple appears to be crouched inside the rural Western Downs farmhouse where they and Gareth's brother Nathaniel Train staged their ambush.
The trio would soon be dead in a firefight after earlier shooting dead constables Matthew Arnold, 26, and Rachel McCrow, 29, and neighbour Alan Dare, 58.
In the video, the married couple appears to admit to the killings, referring to police as "devils and demons" before Gareth Train says: "They came to kill us and we killed them."
The video has been labelled a "vile murder confession" by Queensland Police Union president Ian Leavers, who called for it to be removed from media sites carrying the footage.
"This is exactly what these cold-blooded executioners wanted," he said in a statement on Friday.
"They wanted notoriety, publicity and fame for their evil, deranged and insane views, and they should be de-platformed immediately and not have their evil amplified."
Queensland police said the footage was distressing, not only to the families of those involved but to other officers across the state.
The two constables and local resident Alan Dare were gunned down in what investigators believe was likely a premeditated attack.
Dressed in camouflage fatigues, the heavily armed shooters rigged motion sensors along the entrance to the property to warn them of police arriving.
Two other officers, constables Randall Kirk and Keeley Brough, escaped while under heavy fire.
A funeral service with full police honours will be held in Brisbane for the fallen officers just before Christmas, while residents of towns near the Wieambilla shooting site will also gather to pay tribute to the victims.
Police continue to probe the Train brothers' online activities, including their involvement in extremist conspiracy groups and forums.
Labor MP Peter Khalil, who chairs federal parliament's intelligence and security committee, told AAP that Australia needed a society-wide approach to counter extremism.
He said national security agencies were being challenged by the increasing pathways to radicalisation made possible by "online echo chambers" and the federal government was prioritising cyber-security strategies and counter-terrorism law reform.
"The pipeline towards extremism needs disrupting at its source not just at the pointy end of the spear where violent attacks are imminent," he said.
"By anticipating the increased raft of national security challenges ... we can take decisive action and counter-measures to improve our resilience."
Home Affairs Minister Clare O'Neil said security agencies were "actively considering" the implications for national security.
"It's really important that we let law enforcement and national security agencies do their job, (but) once the picture does start to clarify, it is likely that radicalisation will form a part of it," she told parliament on Thursday.
"It is absolutely clear ... that conspiracy theories, disinformation and misinformation ... are being turbocharged by technology into terrible acts of violence."
Opposition Leader Peter Dutton, a former Queensland police officer, likened the killer trio to Islamic extremists and raised serious concerns about online radicalisation.
The head of the Australian Security Intelligence Organisation, Mike Burgess, previously expressed concerns with the rise of online radicalisation.
