A MENTALLY unstable mother who hatched and hid a plan to kill her three children before enacting the tragic plot "fell through the cracks" of the Victorian mental health service, a homicide detective told the State Coroner today.
Sen-Det Michael Cashman told State Coroner Ian Gray that the 36-year-old mother had shown symptoms of mental illness and schizophrenia since childhood, before she killed her children and herself.
She had been in hospital five times and allowed custody of her youngest children, the court was told.
"Her battle with schizophrenia is not unique in our community," Sen-Det Cashman said in court today.
"However, from time to time the community is subjected to an incident like this one that is so horrific that it defies belief.
"In short, her case simply fell through the cracks of the mental health service and had done so for nearly twenty years."
They all died in a house fire at the mother's rental property in Heidelberg Heights in January 2011. The elder daughter and son suffered horrific stab wounds.Judge Gray is presiding over the inquest into the death of the mother, her eldest daughter aged 18, younger daughter, 13, and son, aged 11.
Sen-Det Cashman told the inquest that the mother was a large and strong woman who lived week to week with her two youngest children while surviving on social security payments.
The eldest daughter, who re-established contact with her family via Facebook shortly before the incident, was described as a young woman with an extensive network of friends.
The younger daughter, who was set to start Year 8, was described as a popular girl involved in a local positive peer program.
The son, a grade 6 student who played Auskick and junior footy, was described as an extremely quiet and shy boy.
The mother had the children to two different fathers, and had lost a son to SIDS - an incident which was said to have contributed to her on-going mental problems.
The children spent time in Department of Human Services care before the eldest daughter's father took full custody of her, Sen-Det Cashman told the inquest.
The younger children ended up living with their mother after their father took temporary custody, but then moved interstate, the hearing heard.
"This period should be viewed as the turning point in the (youngest children's) lives for, despite (the mother's) significant psychiatric history and her inability to manage her illness, there was no action taken by any party to ensure either of the children's long-term safety," Sen-Det Cashman said.
The mother, often seen wearing dark sunglasses and known to ignore other people, was said to be a difficult tenant and lived with her windows permanently covered.
After the eldest daughter re-established contact with her sister in 2010, the mother expressed her displeasure that the 18-year-old had a boyfriend, the inquest heard.
The hearing was told that in one Facebook message, the mother told her eldest daughter in an over-friendly Facebook message: "Celebrate 2010 like there is no tomorrow."
Despite holding fears about her mum, the eldest daughter - and her boyfriend - visited the mother's home in January 2011.
Upon their arrival, the mother pushed the boyfriend into a wall.
"Why don't you leave us alone," she said to the boyfriend.
"She's all I've got."
She then pulled her eldest daughter inside the home, locked the door and attacked her.
The house then exploded in flames, Sen-Det Cashman said.
Firemen entered the burning home but were forced out by flames.
A knife and matches were found in the bathroom.
Sen-Det Cashman said it appeared that despite her mental issues, the mother had been cunning enough to hide her "disturbed state of mind", and was able to formulate and enact her plan to kill her three children.
"I believe she meticulously planned the murder of her three children in the months before the incident," Sen-Det Cashman said.
"She used Facebook and telephone calls to coax (her eldest daughter) to attend the property.
"She was functioning well enough to drug (the younger children) before dousing the premises with fuel.
"She even held an internal door shut to obstruct firefighters trying to rescue the occupants to ensure her children and herself died that day."
A DHS witness told the inquest there was no report or evidence suggesting the mother had ever abused or harmed her children before the incident.
The witness said files suggested she was in fact an attentive, loving and possibly over-protective mother.
Judge Gray will deliver a finding at a later date.