Close friends of the 18-year-old man shot dead by counter terrorism police in Melbourne say they're struggling to understand what happened.
On Tuesday night, Numan Haider was asked by police to come to the Endeavour Hills police station to be interviewed.
Authorities say the meeting in the carpark of the police station was supposed to put him at ease.
But it's alleged the teenager stabbed two police officers - one from Victoria Police and one from the Australian Federal Police, before he was shot dead.
A friend of Haider, who only wants to be known as Ali, said the attack was completely out of character.
"I was shocked. He was such a nice guy. Everyone loved him," he said.
"There's not one person you can mention that hated him. He was a very great guy, a very nice humble guy. I never expected him to do something like that."
Numan Haider was born in Afghanistan, but arrived in Australia as a young child.
Growing up in the south-eastern Melbourne suburb of Narre Warren, his friends said he was just like any other teenager.
He enjoyed camping, swimming and the occasional barbecue.
Ali said Haider didn't tell anyone about his meeting with police, and nothing in his behaviour suggested anything out of the ordinary.
But Haider was upset by the recent decision to cancel his Australian passport, reportedly because authorities suspected he was planning to go to fight with the Islamic State group in either Iraq or Syria.
Ali said Numan had been planning an overseas trip, but not to Iraq or Syria.
"He just wanted to go to Afghanistan to get married," he said.
"He was no part of this ISIS crap. He had nothing to do with all that stuff. This is all propaganda.
"He showed no signs of terrorism. He was a very happy guy - a normal 18-year-old that loves life... he was going out having fun, and having food every day with his friends. There was nothing abnormal about him."
Ali said Numan tried to find out from the Foreign Affairs Department why his passport had been cancelled. But the response from authorities only riled him more.
"He was really upset. He didn't know why. He wanted to know," Ali said.
"He kept making phone calls to the head office. At the start they were telling him how many days he's got left, but out of nowhere ASIO got involved and said the office people can't tell you anything right now so call the Canberra office.
"They would tell him something random like nothing that would be helpful to him so he would just get mad even more."
Ali said Numan was also upset over the way authorities had been monitoring him over the past three months.
"I think something provoked him," he said. "The government didn't have a reason to take his passport. They took his passport. They kept harassing him.
"They kept going to random people and asking about him. He felt like he was in prison. He would always talked about him being in a prison."
According to Ali, Numan did have some contact with the Melbourne-based Al-Furqan group, which was raided by police in 2012.
He says he doesn't believe this contact was recent, but even if it was, he sees no harm in it.
"I don't know much about the group. It looks like a nice place. Everyone's young, everyone's praying there, nothing radicalised with the place," he said.
"It's all propaganda. People are just making stuff about it. Numan was never part of al-Farqhan. He might have gone there once or twice, maybe maximum three, four times just to pray there but it's not a gym.
"He had no membership to go there and sign and everything like that. He just came in and out. There's nothing radicalised going in there."
An image posted on Numan Haider's Facebook page last week shows him wearing a balaclava, and holding an Islamic flag.
But Ali claimed it was his way of getting back at authorities - and the flag is not the same one that Islamic State militants are often seen holding.
"He put them up to be a smart-arse to the police," he said. "He put photos of him with balaclava on and a photo of the Islamic flag, the flag of faith, not the Al-Qaeda or ISIS flag."
Ali said Numan's family is equally shocked over what has occurred.