The Australian Defence Force (ADF) has introduced changes after a soldier was killed during a live-fire training exercise.

The Department of Defence is in court over the death of 25-year-old Private Jason Challis, who was fatally shot during an exercise in the Northern Territory in 2017. 

Private Challis's platoon was engaged in locating and shooting dummy targets made of plywood, but a series of safety protocols were ignored in the lead-up to the shooting, according to evidence presented in the Darwin Local Court this week.

The department has already pleaded guilty to a workplace safety charge.

Colonel Richard Parker told the court that improvements had alreayd been put in place, including a database of personnel qualified for training, safety checklists requiring sign-off and plans to build new facilities.

“We will use those facilities to gradually ease ourselves back into the training of our soldiers in live-fire operations,” he told the court.

Fefence lawyer Fiona McLeod told the court that there were three “clear causal failures” identified in the exercise, including a failure to rehearse without ammunition so “participants are not being tested or surprised by what they find”.

“Although these were requirements, there was no signing off that each of these critical things had happened by the officer-in-charge and up the line,” she said.

Ms McLeod told the court Private Challis's platoon had approached a building from a different direction than earlier groups, and that some members peeled away, which caused the exercise to be halted and reset.

Somehow, Private Challis, who was less than a year into his service, came to be positioned in line with a concealed target.

Ms McLeod said the second failure was a lack of marking of dangerous spaces as required, and the third came when safety supervisors present did not account for all personnel.

“The failure to recognise he was missing is obviously significant, with catastrophic consequences,” she said.

“They did not know and could not see that Private Challis was behind the building and behind the target.”

Judge Elisabeth Armitage said; “With all of these mechanisms in place and a failure of any of them to work, it seems to point to a catastrophic failure to comply with the work health and safety duties”.

Defence officials have conceded the death was avoidable.

The matter returns to court in June.