We are gradually learning more about the troubled life of Bourke Street terror attacker Hassan Khalif Shire Ali.
The Age reports Ali had grown increasingly "delusional" in the weeks before his deadly rampage in Melbourne.
Isse Musse, an imam and friend of Ali's family, has told the newspaper Ali was "complaining he was being chased by unseen people with spears".
Another source said his life had "spun out of control" as he dealt with mental health and substance abuse problems.
Ali had been kicked out of the family home several times. Less than a week before the attack he was seen "storming out" of the property and appeared "agitated".
The Sunday Herald Sun reports he had recently from his wife.
On Friday afternoon, the 30-year-old pulled up in Bourke Street in his four-wheel drive containing gas cylinders turned to their open position, in what police said was a failed plan to cause an explosion.
The Somalia-born Shire Ali then stabbed three men, including the popular 74-year-old Italian restaurateur Sisto Malaspina, who died at the scene. The two other victims are now recovering in Royal Melbourne Hospital.
During the attack, police and civilians tried to subdue Shire Ali before a new police member, only three months out of the academy, shot him in the chest. Shire Ali died in hospital.
Australian Federal Police acting Deputy Commissioner Ian McCartney told reporters on Saturday that Shire Ali was known to have held radical views and that his passport was cancelled in 2015.
He said it was believed Shire Ali was "inspired" by Islamic State rather than having direct links with the organisation.
"The assessment was that person was not a threat at that time," Mr McCartney said.
"Obviously, a focus of the investigation will be ... how and why and when and where he moved along that path of radicalisation."
Police confirmed in a statement that joint counter terrorism team investigators executed search warrants at two addresses in Werribee and Meadows Heights on Saturday morning.
Premier Daniel Andrews said he had been briefed by police and intelligence agencies, including ASIO.
"This person (the attacker) was as much on a list because of his familial connections and others that he associated with as he was for any conduct that he had been involved in," he said.
"No history of violent offending, and I wouldn't go any further than that." Mr Andrews said he had not received any advice that security measures in Bourke Street and surrounds needed to be boosted.
Prime Minister Scott Morrison said Shire Ali had violated the nation's trust.
"The greatest threat of religious extremism in this country is the radical and dangerous ideology of extremist Islam," he said.
Mr Morrison said Ali was one of about 400 people on a national ASIO terror watch list.
"Here in Australia we would be kidding ourselves if we did not call out the fact that the greatest threat of religious extremism in this country is the radical and dangerous ideology of extremist Islam," Mr Morrison said.
"There is a special responsibility on religious leaders to protect their religious communities and to ensure dangerous teachings and ideologies do not take root here."
HEROIC 'TROLLEY MAN' SPEAKS
A bystander dubbed "the trolley man" for taking on an armed terrorist with a shopping cart during the deadly terror attack in Melbourne has said he is "no hero" as his story comes to light.
Michael Rogers, 46, attempted to help police officers stop Hassan Khalif Shire Ali during Friday's Bourke Street terror attack. One person had already been stabbed to death and another two were injured.
Mr Rogers, who is homeless with few possessions, began ramming a shopping trolley into the terrorist in a bid to help.
"I threw the trolley straight at him, and I got him. I didn't quite get him down, though. I'm no hero," Mr Rogers told Seven News' Robert Ovadia from the scene of the attack.
Mr Ovadia later told the program, "people think he deserves some sort of award for being a hero. He doesn't see himself necessarily as a hero but believes he did help save lives and defend his city as well."
The Sunday Herald Suntracked down Mr Rogers on a park bench, amid a nationwide bid to find the humble hero, just 24 hours after he risked his life to save others.
The newspaper reported that Mr Rogers is homeless, but wasn't concerned when his phone was smashed during the fight, despite not having the means to replace it.
Mr Rogers was one of two bystanders who stepped in as the killer tried to claim more victims in the city. Witness footage of the incident uploaded to social media showed Mr Rogers running to one side of the street to get the trolley before pushing it towards Ali who was wielding a knife and lunging at police.
The trolley appeared to startle Ali before the man who pushed it tripped and fell to the ground. The terrorist then ran across the road, followed by police, as Mr Rogers got up and gave chase, pushing his cart towards the attacker a second time.
His actions gained him widespread praise on social media by users who dubbed him "trolley man" and called for him to receive a medal or be made Prime Minister of Australia. Mr Rogers was reportedly unaware of the attention being heaped on him for his actions.
One witness said she spoke to Mr Rogers at the scene and he told her his actions were "just instinctive to help the police protect the safety of others", the Herald Sun reports.
Mr Rogers told 7 News that he believes he did help save lives.
"I've seen the trolley to the side so I've picked it up and I ran, threw the trolley straight at him, got him, but didn't get him down," he said.
"I did that motion quite a number of times but it just wasn't getting him down."
Moments later, Ali was shot in the chest by police, before he died in hospital.
MELBOURNE COFFEE ICON KILLED IN ATTACK
Three people were stabbed in the frenzied terror attack, with one victim dying at the scene.
A 26-year-old and a 58-year-old were taken to hospital with non-life threatening injuries.
Melbourne coffee icon Sisto Malaspina has been identified as the murdered victim.
Staff at Pellegrini's Espresso Bar, a well-known cafe Mr Malaspina had owned for over 40 years, have been in mourning since the incident, The Herald Sun reports.
The 74-year-old took over the coffee bar in 1974 and maintained the tradition of the original owners. The popular establishment is well-known for its traditional Italian cooking and longstanding menu.
"Pellegrini's was the number one in the way it did things, the way things should be done — fresh ingredients, taken from the growers to the market to the shop," Mr Malaspina told Hospitality Magazine last year.
"Everything done by hand. No mechanisation, no additives. Everything was simple, fresh and beautifully put together.
"And it hasn't changed at all. It's still the same menu, prepared in the same way. Slow cooking, no machinery, done by hand … This is the way food should be done. It's not contemporary food. It's secular, traditional, home cooking."
The surviving 58-year-old victim has been named as Rod Patterson, a businessman from Tasmania. In a tweet, Tasmanian Premier Will Hodgman praised him for his bravery, saying "a nicer bloke you wouldn't meet".
His wife Maree posted on Facebook that Rod was "doing OK given the circumstances".
"Unfortunately we got caught up in the attack in Bourke Street this afternoon and Rodney was hurt — good news is he is in a great hospital and doing OK given the circumstances — can't take calls at the moment but will speak to everyone when I can," she wrote.
"Thanks to everyone for their wishes and caring."
The 26-year-old victim, who was a security guard, has not been named publicly.
An Ambulance Victoria spokesperson earlier revealed that one of the survivors sustained a neck injury and the other, a head injury.
Police officers also received minor injuries, one of them from being punched, and some cuts and scratches.
POLICE STORM KNIFEMAN'S FAMILY HOME
Bourke Street reopened around 6:15am Saturday as investigators finished assessing the scene of the deadly terror attack.
The Melbourne road had been shut off from Swanston St to Russell St as forensics and bomb experts examined the area.
Meanwhile, police surrounded a house linked to Ali with officers standing guard at the Werribee home from around 8am Saturday, The Herald Sun reports.
It's understood the attacker's family were inside the house and co-operated with police.
Police Commissioner Graham Ashton said Ali was known to counter-terrorism authorities, both "at the national level" and to the state police.
He said Ali's plan to ignite an explosion usin gas cylinders failed.
"We're certainly confident it was a terrorist attack and that's the way we've been treating it overnight," he told The Today Show. "He's pulled up in a car with gas cylinders. It looks like he's attempted to ignite a fire in the car … we believe with a view to ignite these canisters with some kind of explosion, but that didn't eventuate.
"Then he's gotten out of the car, we allege with an attempt to cause serious harm to the public."
He said Ali has a prior criminal history in relation to driving offences, theft and previous cannabis use.
Mr Ashton confirmed police had spoken with the knifeman's wife, in contrast to previous reports that she had gone missing.
"We know where his wife is and we have spoken with his wife, and she is not missing," he said.
Mr Ashton commended the Victorian police officers' response to the incident, saying: "Obviously it was at their own personal risk when they arrived and intervened and did their duty. It has resulted in the death of the offender.
"You can see from the footage, it is fairly dramatic footage that was recorded and has been played on social media. They were very brave at the scene."
He also commended members of the public for attempting to support the police in the incident.
Police said there has been nothing so far to suggest the latest attack was inspired by the James Gargasoulas attack on Bourke Street Mall last January.
The Islamic State terror group has taken responsibility for the murderous attack, although the group's Amaq news website provided no evidence for the claim.
"The one who executed the ramming and stabbing operation in Melbourne (..) is one of the fighters of the Islamic State and he executed the operation in response to (a call) to target the citizens of the coalition," Amaq said.
PRIME MINISTER'S WARNING
In Saturday afternoon's press conference, Mr Morrison said no religion was immune from extremism and that it took many forms around the world.
Mr Morrison said he had longstanding relationships with the Muslim community and it was them who had raised with him their concerns about radicalism in recent years.
"I have sat in the living room of a family whose four sons went and fought for ISIS," he said.
"And they all died. I have seen the look of complete loss in the eyes of a mother and a father … confused by people who came and corrupted their children."
Mr Morrison urged religious leaders to protect their communities to ensure "dangerous teachings and ideologies" didn't spread in Australia. "They must be proactive, they must be alert and they must call this out in their communities," he said, adding the government and wider community needed to work respectfully with them.
Mr Morrison also urged Australians not to be intimidated by Friday's attack. "Keep being yourselves, keep being Australians," he said.
"Be proud of who you are, because I know you are and that is what will ensure we will always defeat this insidious evil that comes at us every single time."
Victorian Premier Daniel Andrews condemned the incident and thanked the police and brave bystanders who had risked their lives to stop the knifeman.
"This is an evil, terrifying thing that's happened in our city and state today," Mr Andrews said.
"We condemn it. We also take this opportunity to thank those very brave and dedicated members of Victoria Police who did all of us proud in their very quick response in very dangerous circumstances. They've done each and every one of us proud.
"Equally, those strangers, people who were bystanders who knew nobody involved, who stepped in without a moment's hesitation, to render support and assistances."
Prime Minister Scott Morrison said he had been briefed about the incident and state and federal agencies were working together.
"I condemn the act of terrorism in Melbourne today that has tragically taken the life of a fellow Australian who has died as a result of this evil and cowardly attack," he said in a statement.
"Australians will never be intimated by these appalling attacks and we will continue to go about our lives and enjoy the freedoms that the terrorists detest."
HOW KNIFEMAN'S ATTACK UNFOLDED
The terror incident began when Ali drove a 4WD into the city about 4.10pm on Friday afternoon and set it on fire.
Commissioner Ashton confirmed that several barbecue-style gas cylinders were found in the car and later rendered safe by the bomb response unit.
According to the ABC, witnesses saw the man crash the car, get out and throw an object into it that set it alight.
Ali then started stabbing members of the public. There were some reports that he yelled "Allahu Akbar" during the attack but authorities later said this had not been confirmed.
Meanwhile, police responded to the incident after receiving reports of a car on fire. When they arrived, they were approached by Ali who punched one of them through the car window.
Two other officers then got out of the police vehicle and attempted to engage him but Ali appeared to want blood.
Footage on social media shows a blue ute in flames and Ali dressed in a black tunic and white pants menacing police with a knife.
In an earlier press conference, Victoria Police Superintendent David Clayton told reporters that when the officers got out of the car, they were confronted by a male brandishing a knife and threatening them.
"Passers-by were calling out that members of the public had been stabbed," he said.
It's at this point "the trolley man" and another bystander holding a chair can be seen moving in on Ali in a bid to help police stop him.
One witness named Markel told ABC Local Radio in Melbourne that bystanders were urging officers to shoot the man.
"A lot of bystanders (were) actually just screaming at the police officers, because the police officers were trying to take the knife off him and arrest him but bystanders were yelling out 'just shoot him, just shoot him'."
Melbourne resident Meegan May told news.com.au she was on a tram on Bourke St heading into the city when it stopped just before Elizabeth St, about a block before the mall. She heard someone start screaming "he's got a knife".
She looked through the back window of the tram and noticed a car on fire. There was a man and two police officers trying to calm him down.
"A moment later, I heard a loud bang; to me it sounded like a gunshot," she said.
Markel Villasin, 22, was finishing his shift at KFC on Bourke St as the drama unfolded.
"Me and the managers ran out and that's when we saw the car on fire and then we saw the guy on the floor and we wanted to help, there were two blokes helping him out already, he was face down pools of blood around his face," he told AAP.
"I'm pretty sure he got stabbed in the face.
"I really wanted to help but I was in shock, I didn't know what to do.
"Because he was on his stomach, they turned him over to see if he's all right, he was still alive."
Bystander Drew Hair told AAP he was walking on Swanston Street when he heard an explosion.
The next thing he saw was a "big dude punching into the police car".
Mr Hair said the assailant was dressed in Islamic clothing and of African appearance and about six foot four inches tall.
"The cops were trying to hit him with batons and he wasn't going down," he said.
An ambulance and about 10 police cars appeared within moments.
A man told Sky News that there seemed to be multiple explosions.
"There was one explosion and fire, then a second explosion and it was like a massive fireball," he said.
Reports on 3AW Radio indicate that witnesses saw the man driving the vehicle "throw something into the back", before the car was ignited.
An eyewitness told 7 News it appeared the car was on fire before it crashed and "exploded".
"I was walking up Bourke St … and we heard this loud explosion. I thought it was a car backfiring but there was flames coming out of the car. It then veered to the left … and exploded in flames," the woman said.
"People were running everywhere. I thought it was like what happened last year so I started running. Everyone started running. It was so scary."
Anyone with information or who witnessed the incident is asked to go to Melbourne West police station to make a statement.
This marks the third attack in the area in less than two years. In January last year, six people were killed and 27 injured after a car was ploughed through Bourke Street Mall, with 28-year-old James Gargasoulas standing trial over the attack.
Last December, a car mowed down 16 pedestrians outside Flinders Street Station. Saeed Noori, 33, was ordered to stand on trial on murder and attempted murder charges.