Criminal Law

By Satomi Hamon


What is the crime of infanticide?

Infanticide is the term used in law to describe the killing of an infant by its mother who was, at the time of the offence, suffering from a mental illness associated with the birth of the child.

The offence of infanticide has a close relationship to the offences of murder and manslaughter, and is only recognised in three Australian jurisdictions.

In New South Wales and Tasmania, the offence of infanticide carries the same maximum punishment as manslaughter. In these jurisdictions, the child killed must be under 12 months.

In Victoria, the offence carries a maximum punishment of 5 years imprisonment and the child killed must be under 2 years.

Examples of infanticide:

  • A mother smothering her 3-month-old son because she is suffering from post-natal depression and he won’t stop crying;
  • A mother drowning her 14-month-old baby because the psychosis that she is experiencing has her believing that the child is the devil (VIC only, due to age of child);
  • A mother failing to take her 1-month-old baby to the hospital despite a very high fever and visible rash because she is depressed and can’t bear to get out of bed.


Infanticide is a controversial offence and there are many arguments as to why it should beabolished in Australia, including that:

  • Women in Australia generally have various options to deal with an unwanted pregnancy, and many more contraceptive means of preventing pregnancy.
  • Healthcare professionals are aware of the mental health issues associated with birth, such as post-natal depression, and can readily refer at-risk women for psychological counselling.
  • The age limit of the victim is arbitrary. A mother who otherwise satisfies the elements of infanticide cannot claim its protection if the child she killed was one day older than the legislation permits.
  • It is a broadly accepted criminal law principle, that a person who commits a crime while suffering from a serious mental impairment should not always be held fully responsible for their actions.

If a mother in the ACT were to kill her child in circumstances that would constitute infanticide she may have two defences open to her.  Mental impairment (often called insanity) or diminished responsibility.

The defence of mental impairment is available when, because of a mental illness or condition, the person didn’t know the nature of their conduct, didn’t know the conduct was wrong or couldn’t control their conduct.  If a person is not guilty on the basis of mental impairment they are usually hospitalised until the authorities are satisfied they are no longer a threat to themselves or the public.  Diminished responsibility reduces what would otherwise be murder to manslaughter where, because of an abnormality of mind the person’s responsibility for the act is substantially impaired.  In the ACT the maximum penalty for manslaughter is 20 years imprisonment.

In 2006, a woman in the ACT suffocated her son who was only a few days old.[1] The woman pleaded not guilty to murder on the basis of mental impairment, with various doctors giving evidence to support this claim, and she was ultimately acquitted on that basis. Dr Sullivan, a consultant forensic psychiatrist, confirmed that ‘the accused was suffering from a postnatal psychosis which would qualify as a mental illness or mental dysfunction’.

[1] R v SP [No 2] [2006] ACTSC 78