Former Canberra Grammar student Private Poate, 23, Lance Corporal Stjepan "Rick" Milosevic, 40, and Sapper James Martin, 21, died when ANA sergeant Hekmatullah fired 26 rounds on them as they relaxed at a patrol base north of the main Australian base Tarin Kowt in August 2012. Private Poate's death prompted a huge outpouring of grief and support for his family from the Canberra community as well as his army colleagues.

In an interview with the ABC's Four Corners program, Hekmatullah said he became so enraged when shown a film of American soldiers burning the Islamic holy book that he decided to start shooting the coalition soldiers he had been working alongside. He also said if such abuse of the Koran continued, he would do the same thing again, but said he had been tortured into confessing.

"Eight Australian officers were busy playing cards. I used this as a good opportunity. I started firing at them, I killed and injured many of them, and then I jumped over the wall of the camp which was made of mud, I got myself to a nearby village, and later on I joined the Mujahideen," Hekmatullah told Four Corners

Hekmatullah was captured in late 2013 and later sentenced to death for the green on blue attack on the Australians.

Despite vowing to do the same thing again, he has asked the families of his victims to help him in his bid to be released from prison.

"I will get a job and serve the country with either the police or the army," he said.

But Private Poate's father Hugh Poate said he had no sympathy for the man who gunned down his son, and said the incident was the result of a serious failure of planning and intelligence.

"The only people who said that it was a spur of the moment thing were the Australian high command, because the appropriate force protection procedures had not been mandated," Mr Poate said.

The Australian Army's report into the incident found there had not been a failure of intelligence, a claim Hugh Poate disputes.

"It was planned. The evidence on the prosecution file for Hekmatullah clearly says it was planned. The Afghan National Army report itself into the incident shows that it was a planned terrorist attack," Mr Poate said.

He said he hoped the death sentence handed to Hekmatullah would be carried out.

He showed absolutely no mercy to our boys. He killed them in the prime of their lives. They had done nothing to him other than befriend him and he turned around and just killed them in premeditated cold-blooded murder ... so yeah I'm rather hoping that the sentence will be carried out."