By his own admission, the US conspiracy theorist Donald Day didn’t have many friends.
The 58-year-old spent much of his time online, uploading YouTube videos about the extreme Christian ideology known as “premillennialism”.
The videos on his now-deleted channel, which he launched in 2018, mostly only attracted a few hundred views. But the fringe end-of-days religious messages, recorded from a rural town in Arizona, resonated with Gareth and Stacey Train in the Queensland township of Wieambilla.
Day, 58, was arrested last week after he was indicted by a grand jury in Tucson, Arizona on two counts of making interstate threats.
One of those related to comments posted online in December 2022 allegedly inciting violence in connection with the incident at Wieambilla, in which two police officers and a neighbour were shot dead.
“From January 2022 to February 2023, Day used social media platforms to express a desire to incite violence and threaten a variety of groups and individuals, including law enforcement and government authorities,” the US Attorney’s Office, district of Arizona, alleged in a statement.
“Following the killing of two Queensland Police Service officers in December 2022, Day posted a video on YouTube threatening any law enforcement official who came to his residence.
“Separately … [it is alleged] Day threatened to kill [World Health Organization director general Tedros Adhanom Ghebreyesus] in February 2023 on the video platform BitChute, calling on others to join him.”
After Day’s arrest, Federal Bureau of Investigation agents searched his remote property, 30km north of Heber-Overgaard in northern Arizona.
In YouTube comments seen by Guardian Australia, Day referred to the Wieambilla shooters, Gareth and Stacey Train, as his “brother” and “sister”. Stacey echoed the warmth between them.
“Don … if we could visit in person, the tea and coffee would be strong and the bread would be rich and hearty – just like the conversation,” Stacey told Day.
Gareth Train began following Day’s YouTube channel in May 2020. Twelve months later Day began exchanging messages with the couple before they accessed another older account he had created in 2014.
In a final video shared by the Trains last year, Stacey told “Don” they would “be home soon” and that they loved him.
The chilling video was filmed after the couple, along with Gareth’s brother, Nathaniel Train, had ambushed police officers with a hail of bullets.
Constables Rachel McCrow and Matthew Arnold were killed after they had attended the property to perform a welfare check on Nathaniel. A neighbour, Alan Dare, was also killed after coming to investigate a fire that had broken out.
Later that evening the Trains were shot dead by police at their rural Wieambilla property.
It wasn’t long until the Trains’ final message was uncovered by the media and questions were raised about the identity of “Don”.
Days after the Wieambilla attack, Day uploaded two now-deleted YouTube videos about the shootings. In the first he spoke about the couple being “on the run”.
“The devils came for them to kill them, and they had to kill the devils themselves,” he said.
“My only brother [Gareth Train] that I can find in the last 15, 20 years is in another part of the world and I have no one here.”
In another now-deleted video, titled “brother sister martyr”, Day said the couple did exactly what their “heavenly father would have done in the same situation”.
Guardian Australia revealed last year that days before the shootout the Trains had also discussed buying “supplies” with Day.
“We are happy and keen for the next stage of the journey,” the Trains wrote. “So it begins.”
The US Attorney’s Office says Day faces a maximum sentence of five years in prison, a fine of up to $250,000 and up to three years of supervised release on each of the two counts.
On Wednesday Guardian Australia uncovered an active social media account which appears to belong to Day.
In a comment posted a week ago, the account voices opposition to the proposed construction of windmills in Heber-Overgaard.
It also references a conspiracy theory about a “UN agenda 2030” which it says are “designed to displace off-gridders”’.
“They will succeed, one way or another ... whether through our consent or the barrel of a gun,” the account writes.
“It will take grit and sacrifice to stop the monsters from erecting any more of those damned things; we either go Geronimo on them, or lose all that we have.”
Conspiracy theorist rhetoric was uncovered on Day’s YouTube channel last year. In a video posted less than a week before the attack, he echoed a far-right “great reset” theory, which predicts a coming end-days scenario with “enforced” vaccinations and bans on Christianity, “freedom” and “private property”.
Another older YouTube account remains active. In one comment on the channel posted several years ago, Day discusses meeting with a group of “constitutional insurgents” in the “scars of the Vermilion Cliffs [in Arizona]”.
“Before we dispersed, we all agreed that a fight is inevitable ... So we have hoisted the Black Flag – no surrender, no mercy – that we might all fight and die well.”
Day has been charged under US law and there is no application in place to extradite him to Australia.
The Queensland police assistant commissioner Cheryl Scanlon said the investigation had “a long way to go” and police had not identified anyone else in Australia who had contact with Day.
An FBI representative, Nitiana Mann, said on Wednesday that the bureau and the Queensland police service had worked “jointly and endlessly to bring this man to justice”.
“He will face the crimes … he’s alleged to have perpetrated.”
