The perpetrator of Friday's Bourke Street terrorist attack had a troubled relationship with his family and had complained of being chased by "unseen people with spears" in the weeks leading up to his deadly knife rampage.

Sources close to the family of Hassan Khalif Shire Ali, 30, say the man's life had "spun out of control" in the past few years, as he struggled with mental health and substance abuse issues.

Hassan Khalif Shire Ali lunged at police with a knife before he was shot in the chest during the attack. Supplied

On Friday afternoon, Shire Ali drove a car - filled with gas cylinders - into the middle of Melbourne's CBD, before setting the vehicle alight and going on a stabbing rampage which killed much-loved restaurant owner Sisto Malaspina and injured two others.

Shire Ali was married and was living in a bungalow at the back of a home in Meadow Heights, which was raided on Saturday.

His parents home, a modest brick residence on a quiet street in Werribee in the city's west, was also raided in the early hours by police.

The family was originally from Somalia, moving to Australia in the 1980s, and it's understood Shire Ali had three brothers and two sisters who attended the Al-Taqwa Islamic College in Truganina.

All are believed to have grown up in the family's home in Werribee.

But Imam Isse Musse, a friend of Hassan Khalif Shire Ali's family, said Shire Ali broke with Somali tradition by moving out of the family home before he was married, raising concern among his family.

They were hopeful his "situation would improve" after he married, but the imam said in recent weeks he had given them fresh cause for alarm.

"[He was] complaining he was being chased by unseen people with spears," Imam Musse said. "They don't know if he's taking drugs or what."

He said they had been worried about the 30-year-old for some time.

The imam described the attacker's family as "very decent" and said they came to Australia more than two decades ago.

Police say Shire Ali was known to ASIO. Authorities had cancelled his passport in 2015, when ASIO received information he was planning to travel to Syria.

Police on Saturday raided the home of Hassan Khalif Shire Ali's parents in Werribee, along with another property in Meadow Heights. Luis Ascui

While he held radicalised views, federal police didn't believe he posed a serious threat, said AFP acting deputy commissioner for national security Ian McCartney on Saturday.

He said Shire Ali was not being actively monitored at the time of the attack. How he came to pose a threat to national security will be investigated by police.

Initial investigations have revealed Shire Ali had links to the Islamic State terrorist group, Mr McCartney said.

"It's fair to say he was inspired," he said. "We're not saying it was direct contact, we're saying it's from an inspiration perspective."

A police officer speaks to a woman who arrived at the Werribee home of Shire Ali's parents on Saturday. Luis Enrique Ascui

Imam Musse said Shire Ali's family worshipped at the Virgin Mary Mosque, which he once headed.

But the spiritual leader said Shire Ali himself had not visited the Hoppers Crossing mosque for decades.

"[He came] many years ago [to the mosque], when he was 11-years-old or so," the imam said. "He hasn't been coming for many years."

Neighbours who live near the Werribee home said the Shire Ali family had lived there for at least decades.

One woman, who spoke to Fairfax Media on the condition of anonymity, said she thought the parents and one daughter live in the house.

Shire Ali and other family members would often visit, she said.

“There was always cars coming and going,” she said. “They were always very smartly dressed and seemed to be polite and educated people. I’d often see the father and would wave to him across the street but they mostly kept to themselves.”

Neighbours remembered Hassan and his siblings riding down the street on their bikes.

“They were always playing in the street and laughing," one neighbour who has lived in the street for almost 30 years said. "[They were] very well-mannered kids.”

A family friend talks to police outside a house being raided in Werribee in connection to Hassan Khalif Shire Ali. Luis Enrique Ascui

On Saturday afternoon, family friends a man arrived at the house in a dark coloured sedan but was ushered away by police.

The man said he was a friend of Shire Ali’s father.

“I’ve known him 30 years, he is a kind and respected man in the Somali community,” he said. “I came here today because I know he is so upset about what has happened and I wanted to visit to see if he was OK.”

On Saturday, Imam Musse said he had spoken to the family in the hours after the attack.

"They were in shock, unbelievable shock," he said.

"They shared the pain of the victim — that victim had a family too ... the two families are sharing in the grief and pain."

Imam Musse, who is head of the Board of Imams in Victoria, said he was personally "angry" after the terrorist attack.

Isse Musse, an imam who knows Shire Ali's family, said the Somali community deplored the attack. Rebecca Hallas

"The Somali community is deploring this incident," he said. "They are a law-abiding community, [they are] hard-working, they look after their families and put their children through school."

He said Shire Ali was "deluded".

"If a person is Muslim and has a mental health problem, then Islam will be one of the things they may speak," Imam Musse said.

A source close to the family said the attacker had mental health and substance abuse issues and was kicked out of the house on numerous occasions.

He had a troubled relationship with his parents.

“He had a difficult time in his life the last couple of years and spun out of control,” said the source.

At the Meadow Heights property, one neighbour said that Shire Ali moved into the granny flat and at the back of the property about a year ago with his wife and young boy.

Police seized what they called a “breadth of evidence” from Ali’s Meadow Heights home, a converted garage.

He said that Shire Ali drove a tradesman ute, and that he had tools in the back including a wheelbarrow.

"I'd see him on occasion, but he'd never make eye contact," the neighbour said.



The neighbour first learned of the attack on Friday afternoon but didn't put two and two together until Saturday morning when he noticed police had raided the bungalow.