Joel Cauchi, 40, had been diagnosed with schizophrenia as a teen and was experiencing psychotic symptoms when he killed six people and injured 10 at Sydney's Westfield Bondi Junction in April 2024.
An inquest has been told Queensland Police had a number of chances that could have been used to plug him back into mental health treatment and medication ahead of the tragedy.
Cauchi was homeless and living apart from his family in Toowoomba, near Brisbane, when he was shot dead by police during his stabbing rampage.
He had stopped taking his medication in 2019 and stopped seeing a psychiatrist in 2020.
As the inquest continued on Tuesday, Queensland police officers made several calls for change including greater numbers of mental health officers within the force.
They also suggested that laws regarding when mentally ill people could be forced to take an involuntary psychiatric examination be amended to become less confusing.
Inspector Bernard Quinlan, manager of the Queensland police's vulnerable persons unit, said the changes were needed to prevent the criminalisation of those with mental illness.
"Mental health shouldn't just be a police response," he told the NSW Coroners Court.
"It's a no-brainer to me that there should be appropriate responses that are health-led."
Counsel assisting Peggy Dwyer said that changing legislation around police powers was "shaping up to be a significant recommendation" at the inquest.
This week's evidence has focused on one particular incident in January 2023 when Cauchi called police to his family's Toowoomba home.
He accused his father Andrew of stealing his collection of knives, telling attending officers that they had to be returned or he would become bankrupt or homeless.
While a follow-up visit to the Cauchi family home was requested, the fill-in police mental health incident co-ordinator for the Darling Downs region saw the email but forgot to action it due to an "oversight".
On Tuesday, the co-ordinator he was filling in for backed the officer despite his mistake.
"His oversight on that email is devastating," she said becoming emotional in the witness box.
"It's not indicative of him as an officer or how he performed my role."
She also backed a call for further assistance, saying police officers were under greater pressure due to increasing numbers of call-outs relating to mental health despite not being trained in this area.
"If it's not bleeding and it's not on fire, the police are the people who have to attend," she said.
On Monday, the court was told that in May 2021, police were called to Cauchi's unit in Brisbane after residents heard a man screaming and the sound of someone being hit.
He told attending officers that he had been slamming his fridge.
Cauchi was also pulled over three times in 2020 and 2021 by highway patrol police for erratic driving, the court was told.
The inquest continues.
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