Westfield Bondi Junction stabbing tragedy: Sobbing parents of crazed knifeman Joel Cauchi slam their killer son

The parents of the Bondi Junction mass killer have admitted their son was a 'monster' who hated women because he was 'frustrated' at being unable to find a girlfriend.

Parents Michele and Andrew Cauchi opened about their 'troubled...beautiful boy' Joel Cauchi, 40, who they said they 'loved so much' until he went on his murderous rampage.

Knife-obsessed Cauchi killed five women and one man at Westfield Bondi Junction on Saturday when he ran through the shopping centre hacking and stabbing at shoppers.

On Monday, his parents said he was a diagnosed schizophrenic who had lived at home with them until he was 35 in Toowoomba, southern Queensland. 

His life went off the rails when he tried to get off his anti-psychotic medication because 'he wanted to have a life' - but instead triggered his psychosis, said his parents.

'How do you love a monster? Give birth to them!' tearful dad Andrew Cauchi said. 

'I loved my son. But he had a fascination with knives.

'He had five or six army commando knives. He had a problem with women, he couldn't get a girlfriend.'

Earlier, Mr Cauchi lashed out at the media pack outside his home in an angry outburst before his wife Michele stepped in to defuse the situation.

Mrs Cauchi said that she was 'so sorry' for what her son had done.

'He was brought up in love. He was a lovely child and he was in the care of his doctors for something like 18 years,' she said.

'He took his medication, Then he asked the doctor if he could come down on it, and she did over a period of a number of years, very carefully giving him warnings of what might happen.

'And when he came off, it was like his eyes had … it had all lifted from him and he wanted to have a life.

'So after living at home until he was 35, he went to Brisbane.'

She added: 'My heart goes out to the people our son has hurt.

'If he was in his right mind, he would be absolutely devastated at what he has done.

'But he was obviously not in his right mind. He somehow had been triggered into psychosis and he'd lost touch with reality.

'We're just ordinary people and brought up our son as best we could.'

Mrs Cauchi revealed her son had been 'top of his class' and that 'his teachers loved him'. 

'He worked hard. He had a lot of friends growing up,' she recalled.

Her husband admitted that his son was awkward.

Mr Cauchi said his son targeted women in the ruthless attack 'because he wanted a girlfriend and he's got no social skills.

'He was frustrated out of his brain.'

Mr Cauchi said he had been 'putting myself through hell' watching footage of his son on the afternoon of the knife attacks.

'But I'm prepared to do that because I love my son and I want to find out what's wrong,' he said.

'You have no idea how beautiful my boy is.'

Mr Cauchi said that when his son was growing up 'everybody said what a lovely son you've got'.

But he said that Cauchi's mental health issues from his late teens and early 20s meant 'you couldn't help him'.

He added: 'I did everything in my power to help him. I'd go down to Brisbane, spend the day with them, take him to the Gold Coast, take him wherever he wanted.

'There's nothing I can do or say that can bring it back.

'My son, my son … I'm loving a monster. He's a monster to me. He was a very sick boy.

'Do you think there's anything that could have been done differently with his mental illness that could have helped?'

Mr Cauchi said he had last seen his son via a selfie video that showed him looking happy on Coogee Beach on February 5, two months before the knife attacks.

His son had said on the video: 'I just want to show you beautiful Coogee Beach,' revealed his father.

'Can you imagine this boy… so happy… in five weeks time or whatever it is committing the atrocity?,'  Mr Cauchi said.

'That's what mental illness is. Mental illness is horrendous.'

Mr Cauchi said that if mentally ill people even 'just raise a knife, they shoot them dead' and he believed that only made it worse.

'You're encouraging the mentally ill to do something crazy so they can get shot,' he said.

'This crime should never have happened. I'm not blaming the police.

'I took five US Army combat knives off him when I brought him up from Brisbane.

'I said, "Look Joe, you're welcome to stay in my place. But you're not going to have these knives here".'

Mr Cauchi denied his son had ever threatened him but added: 'He was really angry. He called the police and accused me of stealing his knives.'