A failed relationship with a Muslim convert left Australian terror suspect Numan Haider devastated in recent weeks.
A friend told Australian newspaper Herald Sun that the 18-year-old Afghani's marriage had recently soured.
Haider's behaviour had caused authorities "significant concern" in the past few weeks. His passport had also been cancelled about a week ago on security grounds.
In his last Facebook post to a close friend, the terror suspect wrote: "Always stand tall, stay firm, strong and proud."
One man, who knew Haider, said Haider recently told him about his divorce and the stress he was under as a result of being investigated for involvement in terrorism activities.
"It (the divorce) was a huge factor in his life. (He and his wife) were living apart. He was very upset," the unnamed man was quoted as saying.
He added that Haider seemed "angry and frustrated". "He seemed angry about his passport being taken and he wanted to know why."
"Haider kept getting harassed by police officers and Australian Security Intelligence Organisation. He said he was annoyed by them, they kept chasing him and pulling him over and harassing his family," the man said.
"They always were knocking on his door, asking questions about him."
Haider was killed on Tuesday evening, having arrived at a police station in the outskirts of Melbourne to attend a "routine" interview.
He was met by two members of the Joint Counter Terrorism Team and greeted them with a handshake before pulling out a knife and attacking both men, with one stabbed in the head, neck and stomach, AFP reported.
One officer fired a single shot that killed him, police said, adding that the teenager was carrying two knives.
The Sydney Morning Herald said he had an Islamic State in Iraq and Syria flag with him and had planned to behead officers and post the images online, although police would not confirm this.
Meanwhile, a constant stream of well-wishers and family have visited Haider's home outside Melbourne yesterday.
The teen's mother, Suraya, has barely spoken since the news was broken to her last night.
"She did not know what her son was doing," the friend told the Herald Sun.
"She is in shock and very upset."
The teen's 20-year-old brother is comforting his parents, the friend said.
He said: "We are in mourning, we have not buried the body, we have not seen the body."
This article was first published on Sep 25, 2014.
Get The New Paper for more stories.