Robert Langdon was released from prison last week after the Afghan president, Ashraf Ghani, pardoned him.
His tearful mother, father and sister were waiting to greet him at Adelaide airport when he returned home on Tuesday night.
Langdon’s Australian lawyer Stephen Kenny was at the airport to greet his client, and said he had endured a long and hellish ordeal that included attacks by Taliban inmates inside Poli Charki prison.
He was targeted because fellow prisoners knew he had worked with US authorities in Afghanistan, Kenny said.
Langdon was a private security contractor working for the US military when he fatally shot an Afghan colleague during a dispute while escorting a convoy to an American base in 2009.
He always insisted he fired in self-defence after his colleague pulled a gun on him. But just five months after the killing, he was convicted of murder and sentenced to death.
That was later commuted to a 20-year jail term, but the pardon has seen Langdon serve less than half that after sustained pressure from his lawyers and the Australian government.
After being freed last week, the 44-year-old told the Wall Street Journal he fed intelligence about al-Qaeda and Taliban prisoners to the Australian embassy from jail.
He also said he had contemplated suicide during his detention.
“I don’t feel anything anymore,” he said.
“I’m numb to everything now. I’m out. I’ll take it a day at a time, as I have done for years. Too much has happened to me.”
Kenny credited an international legal team and sustained pressure by Australian authorities for Langdon’s release from a very dangerous situation.
“Some of his fellow prisoners, who were mainly Taliban, knew he’d worked with US authorities. He was threatened on a number of occasions and was attacked while in prison. It was a very dangerous place for him to be,” he said.
Kenny, who visited Langdon in jail, said his own review of court files in Afghanistan had exposed some glaring holes in the case.
“For example, one of the judges had commented that they were relying on a statement from a Nepalese security contractor but when you read that witness’s statement, he said he was asleep in the back of someone’s car and never saw anything,” he said.
“The circumstances of the shooting were very difficult and dangerous and Robert has always maintained that he shot after a gun was pulled on him first.”
Kenny said he felt privileged to be present for the family reunion.
“There was such joy to have him home and it was wonderful to see how happy the family was. It was a very joyous reunion and he had a big grin on his face.”