Nathaniel Train’s sudden spiral from respected primary school principal to cold-blooded cop killer started with a heart attack that struck as he battled an exams cheating scandal.

Nathaniel, his brother Gareth Train and sister-in-law Stacey were shot dead by police after executing officers Matthew Arnold, 26, and Rachel McCrow, 29, as well as his neighbour Alan Dare, 58.

The murderous Trains ambushed the officers and their two colleagues - who narrowly escaped with their lives - outside the family’s rural home in Wieambilla, three hours west of Brisbane.

Their motive is as yet unclear, but it has since emerged that Gareth Train was an active member of a number of conspiracy theory websites, where he posted a series of extreme comments.

However, his brother Nathaniel, 46, was well-respected in Queensland’s education sector and had a reputation for turning around struggling schools.

But a heart attack and NAPLAN cheating scandal that engulfed one of his schools saw his career abruptly come to an end.

He was principal at Innisfail East and Yorkeys Knob State Schools in Far North Queensland, and he was lauded for making the latter one of the best-performing schools in the state.

Nathaniel Train was principal at Innisfail East and Yorkeys Knob State Schools in Far North Queensland. Photo / Supplied

But it all came crashing down after he became executive principal of Walgett Community College Primary School in New South Wales in 2020.

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One student, who may have been related to a teaching assistant, was unable to answer the first two questions on their NAPLAN test but then got all of the remaining 34 questions correct, Daily Mail Australia reported.

Nathaniel Train reported this to the NSW Department of Education but was said to be unhappy with the lack of action.

In August 2022, he suffered a massive heart attack at the school and was saved by teachers who rushed to his aid.

But he didn’t stop his campaign to resolve the cheating scandal, firing off 16 separate emails to the education department.

When that didn’t work, he tried to call on NSW One Nation leader Mark Latham for help.

Latham told Daily Mail Australia that Nathaniel Train “was cogent” when he spoke to him.

“He knew what he was talking about and it was supported by documentation. He wasn’t ranty with me, but he was certainly bitterly disappointed with the education department.”

Six people, including two young police officers, were shot and killed in Wieambilla, Western Downs, Queensland on December 12. Photo / Harry Clarke, Country Caller

Nathaniel Train left his job in March 2022 and walked out on his wife. He was last in contact with her in October, police said, and a missing persons notice was issued for him four days ago.

Four police officers attended the isolated property at 251 Wains Rd on Monday afternoon to carry out the “routine missing person inquiries” at the request of NSW Police.

He was last seen in Dubbo in NSW on December 16, 2021.

In 2003, Walgett’s pre-school, primary and high schools were restructured into the Walgett Community College, and in 2021, the Sydney Morning Herald reported on the serious issues within the wider campus, revealing serious staff shortages and rampant violence within the school.

Latham confirmed he spoke with Train earlier this year after he sent an email outlining concerns he had to the education department.

In the March 7, 2022, email, the then-school principal reportedly outlined a number of hypothetical scenarios which Train apparently believed needed to be addressed by the department.

Latham referenced Train when posing a question in state parliament to Education Minister Sarah Mitchell about the state of Walgett’s school this year.

The NSW One Nation leader has now confirmed that he visited the school after Train informed him he was “very unhappy” with the situation at Walgett Community College Primary School.

“Because of Nathan I went up to the school,” Latham told The Daily Telegraph.

“The news this morning is a shock and a tragedy. It’s a confusing situation.”

He said his dealings with the man had “no context at all in relation” to what happened on Monday at the Queensland property.

“All I can tell you is he left the teaching service in NSW and mid-year he was talking to me,” Latham said.

“He had a feeling of disappointment and frustration with the education department that had left him feeling bruised and drained I would say.”

Train also previously served as principal of Yorkeys Knob State School, with a 2017 Cairns Post article about a school fundraiser describing him as a “mild-mannered school leader”.

In a NSW Police appeal for information on his whereabouts posted on social media just days ago, one person commented that he was their children’s ex-principal at Yorkeys Knob State School in Queensland’s far north.

“Oh no! Hope he is OK, good bloke,” another responded.

“Yeah, he was,” another agreed.

Train worked at the school as recently as 2019, when it came in at number 25 in a ranking of Queensland’s best NAPLAN results for the year, recording the best primary school results in the Far North.

At the time, Train told the Cairns Post that “supportive parents, dedicated teachers and support staff” were key to the school’s success.

“We have a consistent delivery of teaching programs, a quality learning environment that focuses on every student being given the opportunity to be a successful learner and students that commit themselves wholeheartedly to their learning opportunities,” he told the publication.

“Our strategy continues to be for each student to strive to be the best they can be. NAPLAN is an opportunity to learn and provides all schools in Australia with point-in-time assessment. It is useful to everyone in education that is looking for continual improvement.

“The students, parents and teachers should be proud of their ongoing success. NAPLAN is reflective of what happens every day at Yorkeys Knob State School.”

Nathaniel Train was also previously the principal of Innisfail East State School — yet another disadvantaged primary school that achieved outstanding academic results during his tenure.

Dubbo police are believed to have lodged the request for assistance with their Queensland colleagues, with insiders telling the Telegraph one of Train’s relatives was known to have an intense distrust of police.

Ronald Train, the father of Gareth and Nathaniel Train, told the Courier Mail that he was grieving the loss of his two children

“I am not going to share anything with you, you can speculate and make up as much as you want. I have lost two children,” he said.

“I have already had conversations with police.”