A Sydney mother will not serve any jail time after a Supreme Court Judge found she was living with severe mental illness when her baby drowned in the bathtub.
The woman, who cannot be named for legal reasons, has been undergoing treatment in a secure forensic hospital since the two-month-old girl was killed in February last year.
She was due to stand trial for her murder but today the Supreme Court handed down a special verdict of "act proven, but not criminally responsible".
All parties, including the prosecution, agreed the woman was suffering from post-natal depression and bipolar disorder at the time and could not be held responsible for her actions.
The 37-year-old woman was initially charged with murder after the baby was found unresponsive in the bath at their home in Shalvey, in Sydney's west.
The baby's father returned home to find the girl in the bath and tried to revive her until emergency crews arrived and took her to hospital, but she could not be saved.
The woman later told authorities she had a "mental breakdown" after the birth of each of her children.
Court documents show the woman saw a GP the day before the baby's death who concluded she had "symptoms of depression, with some test results raising concerns of self-harm or risk to (the baby)".
While she also admitted to thinking about suicide, she told the doctor she "had never planned to kill herself" and that she "loved her baby and would never hurt her" before being sent home with anti-depressants.
She has since been assessed by several forensic psychiatrists, including Adam Martin, who concluded she was "clearly mentally ill at the time".
"It is likely that she experienced a post-partum psychosis in the context of underlying bi-polar disorder, which tragically led to her having highly disturbed and distorted beliefs and hallucinatory experiences, severely clouding her judgement, and speculatively making her feel scared and hopeless," Dr Martin wrote.
Justice Helen Wilson accepted the assessment, finding "whilst the accused likely knew the nature and quality of her act, she did not know that the act was wrong because of a mental health impairment she suffered at that time".
The woman will remain in a secure mental health facility until her case can be assessed by the Mental Health Review Tribunal.
