Aussie mum who killed eight kids won't stand trial

Raina Thaiday
Raina Thaiday stabbed to death seven of her own children and her niece in 2014. (Nine News)

A Cairns woman who stabbed her seven children and one niece to death in 2014 was suffering "schizophrenia at its very depths" an Australian court has heard.

Raina Thaiday had been smoking up to 20 cones of cannabis a day before the tragedy in December 2014. The 37-year-old believed she was the "Chosen One", and was obsessed with protecting her family from demons.

Australia's Mental Health Court last month found Thaiday was "of unsound mind" when she massacred the eight children. The decision was not allowed to be published for 28 days.

On December 19, Thaiday heard a "dove call" telling her it was time to act, the court was told.

She first killed the family's pet duck, then stabbed the four boys and four girls, aged from two to 14 years old, CH7 reported.

After realising what she had done, the woman who was known to be a doting mother stabbed herself 35 times and waited to die on the family home's front porch, where her adult son Lewis Warria found her and called emergency services.

"To her way of thinking at that time what she was doing was the best thing she could do for her children, she was trying to save them," Justice Jean Dalton said.

Psychiatrist Frank Varghese told the court it was "schizophrenia at its very depth and at its worst".

"This is quite a unique case and a horrendous case, the likes of which I've never seen before," he said.

The court heard Thaiday had remained in a state of psychosis until mid-2015, and had since relapsed twice, when she expressed the desire to kill other patients in the high-security facility where she is held.

Thaiday, also known as Mersane Warria, was charged with eight counts of murder but won't stand trial after the Mental Health Court ruling.