A Sydney woman who decapitated her mother and dismembered parts of her body copied horror movies which she blamed for her "sick thoughts," a jury has been told.
Growing increasingly agitated by a living arrangement at home with threats from her mother she would be put back into a mental institution, Jessica Camilleri "saw red".
The now 27-year-old told Professor David Greenberg she was in a fit of rage when she dragged her mother by her hair down the corridor before opening up the knife drawer "to scare her".
"I think I had sick thoughts. I used to watch horror movies. I got it off horror movies," she told him.
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.
Camilleri has pleaded not guilty to murdering her mother at their St Clair home in Sydney's west in July 2019.
Both the prosecutor and defence barrister agree Camilleri stabbed her 57-year-old mother, her sole carer.
The jury must decide whether the charge can be reduced to manslaughter with the partial defence of being unable to control her actions due to a substantial impairment of the mind.
The crown witness told the NSW Supreme Court on Thursday that Camilleri, who suffers from complex psychiatric disorders and autism spectrum disorder, among other conditions, went off her medication six months before the attack and had sought help from an alternative healer.
She told Dr Greenberg about developing crushes on men she would randomly ring, including Matthew Layfield who at one point she "relentlessly targeted" along with his employees.
Mr Layfield owned a meat business in 2019 when the phone calls started and would "turn ugly" whenever someone tried to end the conversation.
Detective Sergeant Grant Gilbert read out Mr Layfield's statement about the harassment that lasted two months.
"'I will stab you and cut your head off with a knife'. It always ended like that, it did not matter who she was talking to," the statement read.
Mr Layfield made regular contact with her mother who said her daughter had developed a huge crush on him after seeing his photograph on the company's website and would "go crazy" when she heard his voice.
After Mr Layfield's friends and family members were also targeted with similar threats of beheading, he contacted Rita Camilleri saying "something needed to happen".
"At her wit's end," the 57-year-old burst into tears and said she did not know how to control her daughter anymore. She had previously confiscated her phones and disconnected her service.
Det Sgt Gilbert found eight copies of the Texas Chainsaw Massacre and five of Jeepers Creepers following a search of the home.
On Thursday family friend Jade Arena was recalled for re-examination about her evidence that she was afraid for Rita's safety and told her she may be murdered.
Ms Arena "definitely" remembers the conversation where Ms Camilleri spoke of her "soft" daughter who "wouldn't hurt a fly".
She described Jessica Camilleri's fixation on not being placed into a mental health facility and how she would "rather kill somebody" than be sent back to such a place.
The trial continues with more evidence from Dr Greenberg on Friday.
Australian Associated Press