Australian suicide bomber Jake Bilardi craved attention and had a death wish, his father says.
Speaking publicly for the first time since his son's death, John Bilardi said he shouldered much of the blame for his son's actions.
It's been reported the teenager died last week during a series of deadly co-ordinated Islamic State suicide bombings in the Iraqi city of Ramadi.
At least 17 people were killed, and dozens injured in the attack, which Mr Bilardi says was orchestrated by the militants.
"He was a prize, a trophy - they used him for their own cause," he told the Nine Network's 60 Minutes program.
"He had a death wish."
Describing him as a shy and lonely boy, Mr Bilardi said he ignored his son's obvious mental and psychological issues when he was a child.
"The buck stops with me," he said.
"He was my son, I knew something wasn't right."
The youngest of six children, Jake was a difficult child who didn't fit in; he craved attention and had many violent outbursts.
Following a messy divorce, Mr Bilardi lost touch with all of his six children but reconnected with Jake soon after his mother died.
Despite growing up an atheist, Jake converted to Islam and quickly became radicalised, watching Islamic State propaganda on his laptop.
Already one to keep to himself, Jake became increasingly withdrawn spending most of his spare time alone in his bedroom.
He soon joined the fight in Syria, and became the poster boy for the terror group.
The 18-year-old's family now struggles with overwhelming sadness and anger about his death.
And despite not having a body to bury, Mr Bilardi says he will create some kind of memorial for his son.
"For Jake my son - not the jihadist, not the terrorist," he said.
"The rest of it can go to hell as far as I'm concerned."
