Geoff Robson-Scott, the partner of Avalon murder victim Lanell Latta, speaks to The Daily Telegraph

Geoff Robson-Scott, the partner of Avalon murder victim Lanell Latta, speaks to The Daily Telegraph

BEFORE stabbing his mother to death, Joel Woszatka saw her face changing and possibly thought she had been “replaced by an alien”, a court has heard.

Mr Woszatka told police after allegedly killing his mother Lanell Chris Latta that “her face changes”.

On the morning of September 18 last year in the beachfront house Ms Latta, 50, was renting from model Gemma Ward, Mr Woszatka took a large knife from the kitchen.

The then 25-year-old walked into his mother’s bedroom and allegedly stabbed her in the chest.

He allegedly punched his mother’s partner, Geoff Robson-Scott several times in the face before fleeing the Avalon Beach home in far northern Sydney.

Psychiatrist Dr Olav Nielssen told the NSW Supreme Court that severe schizophrenia sufferers commonly thought their mothers “have been replaced by an alien or a person who is not her”.

Dr Nielssen was giving evidence in the judge-only trial of Joel Woszatka, who has pleaded not guilty to murder by reason of mental illness.

Asked by defence counsel Ertunc Ozen if Mr Woszatka had heard hallucinatory “command voices” telling him to harm or kill his mother, Dr Nielssen said they were “relatively rare”.

But he said killing one’s own mother “is most likely to be perpetrated by a person with schizophrenia”.

“Matricide has been described as the schizophrenic crime,” Dr Nielssen told the court.

Dressed in a blue suit, collared shirt and tie, the accused sat impassively staring straight ahead as the court heard there was no contest that he had caused his mother’s death.

Dr Nielssen described a decision to take Mr Woszatka off antipsychotic medication six months before the alleged killing as “a tragic error”.

The drugs caused “lethargy, loss of motivation, poverty of speech … neglect of self care, difficulty in planning”.

In 2015, Mr Woszatka had disclosed to doctors “homicidal ideas … thoughts to kill his mother”, the court heard.

Dr Nielssen described schizophrenia as a “disease of the brain”.

He said it caused “hallucinations, voices … persecutory delusions that you are in danger … under surveillance, a victim of persecution”.

Diagnosed with a “severe and disabling form” of chronic schizophrenia, Mr Woszatka had been placed by community order on monthly injections of a high dose of medication.

On the trial’s second day before Justice Helen Wilson, Dr Nielssen agreed that smoking cannabis “brings on schizophrenia” earlier in a person with an inherited disposition for the disease.

“Whether it actually causes the illness is not clear,” he said.

Dr Nielssen agreed with Crown prosecutor Paul Lynch that when Mr Woszatka allegedly punched Mr Robson-Scott in the face he was in the grip of mental illness.

The psychiatrist said that in 140 homicide cases in which he had forensically examined accused killers, a large proportion of those who had killed “a family member, often a mother” were schizophrenic.

“It’s not unusual. Ten per cent of homicides in Australia are committed by people with schizophrenia,” he said.

“It’s a huge over representation.”

Dr Nielssen said that Mr Woszatka had been treated for his mental health condition in custody following his arrest on the day of the killing, but that it was “very slow”.

In a final submission, Ertunc Ozen told Justice Wilson he did not oppose a verdict of not guilty by reason of mental illness.

Her Honour will deliver the verdict and her judgment on Thursday.

candace.sutton@news.com.au