A six-hour siege west of Brisbane on Monday ended with two police officers, a member of the public and three offenders dead.
Details about what happened are still limited, but Police Commissioner Katarina Carroll and Queensland Police Union president Ian Leavers have spoken publicly about the event.
Officers 'executed in cold blood' on hunt for missing man
Four police officers investigating the disappearance of Dubbo man Nathaniel Train went to a property on Wains Road, Wieambilla, approximately 300 kilometres west of Brisbane, at about 4:30pm on Monday.
"I'm told as soon as they'd entered the property, they were just inundated with gunfire, and they never had a chance," Mr Leavers told ABC News Breakfast on Tuesday morning.
Three of the officers were shot, Mr Leavers said. Two of those who were hit dropped to the ground.
"The other two police, they were able to take cover and retreat a little bit," Mr Leavers added.
"The two police who were on the ground, they were executed in cold blood."
The two officers who were killed have been identified as Constable Rachel McCrow, 29, and Constable Matthew Arnold, 26.
"Our colleagues who were responding and the two police who have survived, they were able to call for assistance," Mr Leavers said.
Offenders started fire to try to smoke out officer who took cover
The offenders then lit a fire, Mr Leavers said, in an attempt to "coax" out one of the officers who had retreated.
He said the "amazing young policewoman", later identified as Constable Keely Brough, had only been working in the force for eight weeks.
"She did not know whether she was going to be shot or she was going to be burnt alive," Mr Leavers added.
"She was sending messages to loved ones saying she was at a point where she thought it was her time.
"She never stopped trying to do the right thing and communicate with her colleagues."
Constable Brough and the other surviving officer, Constable Randall Kirk, both 28 and from Chinchilla Police Station, were taken to Chinchilla Hospital.
Constable Brough was taken to hospital as a precaution and has since been released, while Constable Kirk remained in hospital on Tuesday afternoon for treatment of a gunshot wound.
The fire caught the attention of a man now identified as Alan Dare, 58, from a neighbouring property.
Mr Leavers said Mr Dare was killed when he tried to investigate the source of gun fire.
"He was shot in cold blood as well, in the back. He did not see that coming," he said.
"This ruthless, murderous trio that we're dealing with showed absolutely no compassion, not only for the police but also for a member of the public who was simply doing what he believed was right to go and investigate and help someone."
The men responsible for the deadly ambush have been identified as Nathaniel Train, a former school principal, and his brother Gareth. Stacey Train, 45, was also killed at the scene.
How did police respond?
Police then brought in aircraft and specialist officers as an emergency was declared and members of the public were urged to stay away from an exclusion zone.
Mr Leavers said "there were 16 frontline police who went in to retrieve their colleagues".
"They were hoping they could get them out to get them some medical assistance, but sadly that was futile.
"Special operations police were called and … under heavy gunfire, they were forced to use their firearms," he said.
From the time police initially attended the property, he said, through to the arrival of special operations police, "they were continually under fire".
Just after 10:30pm, some six hours after the four officers had originally arrived on scene, the siege came to an end.
Two men, Nathaniel and Gareth Train, and a woman, Stacey Train, were shot dead during a confrontation with police.
What happens next?
A crime scene has been declared and the Public Safety Preservation Act provisions remain in place.
The Queensland premier has announced flags at government buildings around the state will fly at half-mast, and officials around Australia, from the prime minister to the local mayor, have joined in to share condolences and pay tribute.
"This is a real tragedy across our region, a large region with a small population," Western Downs Mayor Paul McVeigh said.
