A teacher with more than two decades of experience brought a replica firearm she made with a 3D printer to school to show students.
The woman took the ACT Education Directorate to the Fair Work Commission alleging her subsequent dismissal was unfair because it was disproportionate and harsh.
In a decision published this week, Commissioner Sarah McKinnon dismissed the application and said the woman "showed an astonishing lack of judgement for such an experienced teacher".
She had been a high school teacher for 22 years when she was fired for serious misconduct in January.
In April 2025, the digital technology and maths teacher, aged in her mid-50s, brought a prohibited firearm with moving mechanical parts to school to show students what they could make with 3D printing technology.
She had made the replica firearm the weekend before using plans downloaded from the internet.
On Monday, April 7, 2025, she "proudly" showed another teacher the replica firearm in the staffroom, demonstrating how the top of the gun could be pulled back and imitating the act of preparing to fire.
The other teacher said, "you can't show that to students," and told her to put it back in her bag.
The maths teacher put the item back in her bag and said words to the effect of: "What is the problem? What have I done wrong?"
She did not show the students the replica gun and took it home at the end of the day, although it was visible in her open bag.
The next day the incident was reported to the principal and the Australian Federal Police were notified.
On April 9, 2025, officers from ACT Policing visited the school and the woman was suspended with pay.
She was escorted off the school grounds and police later searched her home, seizing the replica firearm and 3D printing equipment. Police formally cautioned the teacher but she was not criminally charged.
The next month she was issued a show-cause notice relating to the termination of her employment.
The teacher responded through lawyers "vehemently" denying any intention to show the replica firearm to students and asserting that she brought it to school with the "sole intention and purpose" of showing it to the other teacher because she wanted to introduce a 3D printing course.
Numerous investigations were then undertaken by the Teacher Quality Institute, the APS Public Sector Standards Commissioner and the Professional Standards Unit.
In a letter to a professional standards investigator, the teacher said she did intend to show the item to students, subject to approval from her supervisor, and apologised for her actions.
After these investigations were completed, she was formally terminated in January 2026.
In the published decision, the commissioner said the teacher's actions "of printing a replica firearm and bringing it to school to show teenage students without realising that this was a bad idea were not simply misguided".
"Replica firearms are prohibited for a reason: they look real," Ms McKinnon said.
"Schools these days are required to be trained in lockdown procedures because of the risk of school shootings.
"Those who witnessed the incident indicated varying levels of concern, with one spending the day thinking about it because it 'didn't sit right'."
The commissioner found that if the replica gun had been shown to the teenage students there were risks that they might make their own replica firearms, or search for similar content on the internet.
The teacher was found to have not been unfairly fired and the application was dismissed.
