How deranged killer who decapitated her own mum bombarded a meat worker she had a 'huge crush on' with 100 calls a day threatening to 'flush his wife's head down the toilet' - despite NEVER meeting the couple

A deranged woman who decapitated her own mother bombarded a meat worker with more than 100 phone calls a day threatening to 'flush his wife's head down the toilet'.

Jessica Camilleri was last week found guilty of manslaughter following the vicious attack, in which she severed her mother Rita's head in their St Clair home in Sydney's west in July 2019.

Before she was jailed, the 25-year-old had developed a 'huge crush' on meat worker and businessman Matt Layfield, 33, who lives in Victoria with his wife.

She saw an image of him online along with a phone number for his business Highland Meats, and would call him and his staff upwards of 100 times each day, a court heard.

Camilleri, who's in custody, will next appear in court for a sentencing submissions hearing in February

The calls generally started out quite pleasant but culminated in Jessica threatening to cut off he and his wife's heads, Mr Layfield told The Daily Telegraph.

She said she wanted to flush his wife's head down the toilet, the New South Wales Supreme Court heard during her trial.

When he eventually learned of Mrs Camilleri's fate, Mr Layfield said he felt sick to his stomach.

He had spoken to the single mother on several occasions about her daughter's behaviour.

Mr Layfield got the sense that Mrs Camilleri was struggling to cope with Jessica's increasingly erratic behaviour in the lead up to her death.  

Camilleri, then 25, stabbed Rita Camilleri more than 100 times in the St Clair, western Sydney, home they shared 

'You could just feel the horror she was going through and in particular on that day when she just broke down on the phone.

'She just felt like there was no help whatsoever for her, I just feel terrible for her.'

Mr Layfield said he never had a doubt that Mrs Camilleri was a 'good-hearted woman' who was isolated and doing her best to help her daughter get the help she needed.

Jessica had developed an unhealthy obsession with horror movies prior to decapitating her mother.

A jury trial heard the 25-year-old, who has extensive mental health conditions and was known to authorities, asked first responders if they could sew her mother's head back on.

Jessica Camilleri 'saw red' in July of 2019 when her mother threatened to send her back to a mental institution 

It was determined that she was not guilty of murder given her lack of understanding about her actions. 

While Jessica has remained in custody since the gruesome attack, Mr Layfield said it has 'played on his psyche' being 'so entangled with something you see in the movies'.  

'I must admit mentally the difference that made for a simple thing like taking the bins out in the dark,' he said.

Friends of Mrs Camilleri previously told Daily Mail Australia she sacrificed so much to support Jessica and care for her through her substantial mental health issues.

Her marriage deteriorated as a result of Jessica's behaviours and even her other daughter felt unsafe being at the home.

The gruesome St Clair murder scene where Jessica Camilleri decapitated her mother Rita Camilleri in July of 2019

But the 57-year-old was tireless in supporting her daughter and ensuring she received the medical treatment she needed. 

After years of increasingly more disturbing outbursts, Jessica claims she 'saw red' one day and began attacking her mother.

Following the brutal attack, Rita Camilleri's head was found outside on the footpath, while her blood-drenched body was on the kitchen floor near her eyeballs, tongue and tip of her nose.

An autopsy found she had been stabbed at least 100 times and had suffered more than 30 defensive type wounds on each hand.

The crown witness told the NSW Supreme Court that Jessica, who suffers from complex psychiatric disorders and autism spectrum disorder, stopped taking her medication six months before the attack. 

Camilleri, who remains in custody, will next appear in court for a sentencing submissions hearing in February.

Jessica Camilleri was found guilty of manslaughter after arguing she was mentally impaired at the time