Women who murder their domestic partners receive longer gaol terms than their male counterparts after being viewed more harshly by the sentencing judges, Murdoch University research reveals.

The study examined 79 domestic murder cases in Australia’s two largest jurisdictions – NSW and Victoria – between 2002 and 2010. There were five female offenders in the study sample. Two of them received the highest sentences, while all five featured in the top 10 sentences handed down by judges.

The highest sentence handed down was 36 years with a non-parole period of 26 years to a female offender in NSW in 2005. Males who killed their partners were handed down an average head sentence of 20 years. The highest sentence imposed was 23 years.

In contrast, the average head sentence for the five female offenders in the sample was 24 years and 9 months, with the highest sentence being 36 years.

Associate Professor Guy Hall, from Murdoch’s School of Law, who oversaw the analysis done by PhD student Marion Whittle, said statistical analyses could not be done because the number of female offenders was so small, but the aim of the study was to compare judges’ sentencing remarks in murder cases involving men against those involving women.

It found that the language used by judges to describe female offenders differed significantly from the language used to described men who killed their domestic partners.

“The judicial commentary surrounding both the female offenders and the female victims frequently relied on stereotypes and traditional notions of marriage, family and femininity in determining an offender’s sentence,” Associate Professor Hall said.

“Women who killed their domestic partners were described as “wicked”, “extremely manipulative”, “callous” or “heartless”. In the case of male offenders, there was often reference to family pressures or a lack of control in their domestic situation in the lead up to the murders. In one case, a judge remarked that the deceased wife was the source of the conflict.”

In eight of the male offender cases, judges indicated that domestic partners were killed as a result of a family dispute, and when the female victim left or intended to leave the relationship, the male offender was left distraught.

Sentencing remarks in a further seven cases highlighted the male offender’s abnormal mental state and subsequent actions were a direct result of the offender’s wife proceeding to leave the relationship.

Judges frequently set out a background of jealousy, betrayal and infidelity to explain the male offender’s behaviour. In contrast, for three female offenders, there was no evaluation of the offender’s psychological state.

Associate Professor Hall said there were no positive comments about the female victims in the judge’s remarks, while a male offender’s previous good behaviour, community ties and work achievements were often taken into account during judges’ sentencing remarks.

“The vast majority of domestic murders in Australia are committed by men,” he said. “Men killing women is endemic in society, and violence is a trait traditionally associated with men, so when women commit murder, societal values are applied and women are often categorised as evil and heinous.

“Women received much longer sentences for similar crimes. It may be an unconscious bias based on societal norms, and possibly a hangover from when provocation laws were still in place.”

PhD researcher Marion Whittle, who spent 12 months analysing the available data in Victoria and NSW, is now examining judges’ remarks in Australian jurisdictions, including Western Australia, in domestic homicide cases, which includes manslaughter. Her findings have not yet been published.

Associate Professor Hall will present the findings of the research at the Herbert Smith Freehills Lecture Theatre at Murdoch University as part of International Women’s Day commencing at 10.30am.