‘Seven times more likely': Unthinkable truth about women who kill

News.com.au

11-07-2025

Australia and the rest of the world has been gripped by the infamous 'mushroom massacre' –which has seen Victoria native Erin Patterson found guilty of murdering three of her husband's relatives and severely injuring a fourth.
On Monday, Patterson was sensationally found guilty of the murder of her father-in-law Don Patterson and mother-in-law Gail Patterson, as well of the murder of Heather Wilkson – her estranged husband's aunt – and the attempted murder of his uncle Ian Wilkinson.
She had prepared a meal of individual portions of beef wellington which included a mushroom pate that contained fatal death cap mushrooms, which are so toxic that just one can kill a person.
Now, Patterson joins a long list of women who have used poison as their murder weapon of choice, with research showing that women disproportionately use poison to kill compared to men.
The mother-of-two – whose husband Simon Patterson had declined an invitation to the deadly luncheon and which was instead attended by his parents, aunt and uncle – had always maintained her innocence in the case, saying that she had inadvertently purchased the deadly mushrooms from an Asian grocer.
The jury did not believe her and agreed with the prosecution's theory that Patterson foraged the death cap mushrooms close to her home and baked them into the beef wellington with the intention to kill.
According to data from the 2012 Federal Bureau of Investigation Supplemental Homicide Report in the United States, women are seven times more likely than men to use poison as a murder weapon.
Psychologist Irna Minauli told news.com.au that women choosing to use poison more frequently than men was due to a range of factors.
'There is actually no difference between levels of aggression in men and women, it is just that the way aggression presents is different,' she explained.
'With men, they often act directly, whereas women may choose to act indirectly or through a third party.'
She added that the weapons men and women use are also different, and that 'women often kill in ways that do not cause death immediately, such as poison.'
Using poison can mean that the victim dies some time later, out of sight of the perpetrator who does not have to witness the direct result of their actions – allowing them to feel an 'emotional distance' from the killing, Minauli said.
'With poison, they don't have to see the impact of their actions directly, unlike when using other weapons where the consequences are more obvious and can involve blood and wounds.'
According to the Federal Bureau of Investigation Supplemental Homicide Report, firearms are actually the most popular weapon of choice in murder cases committed by both men and women.
However, if you remove guns from the equation, men most frequently use beatings, blunt objects and strangulation to kill, whereas women use stabbing, asphyxiation, poison, fire, drowning, explosives and defenestration (throwing someone out of a window).
Research has also shown that poisoning victims are usually younger (including children) or older – and young adults are much less likely to be killed by poison. It is also usually used in cases where the killer knows the victim, rather than against a complete stranger.
Patterson's murders certainly fit this profile, even though she tried to deceive law enforcement and the jury by claiming that the poisonings had been a tragic accident after she inadvertently added poisonous mushrooms to her guests' food.
Her case however is not as unusual as it sounds.
In 2016, Australian permanent resident and Indonesian national Jessica Kurmala Wongso was accused of poisoning her friend Wayan Mirna Salihin in a coffee shop in an upscale mall in Indonesia's capital Jakarta.
Even though she always maintained her innocence, she was accused by prosecutors of inviting Salihin to the coffee shop, before arriving early and ordering her a Vietnamese iced coffee, to which she then added the powerful poison cyanide.
After sipping the drink, Salihin immediately collapsed in the coffee shop and was pronounced dead on arrival at a local hospital, although the defence unsuccessfully argued that small traces of cyanide found in Salihin's organs following a partial autopsy could have been the result of embalming fluid used to prepare her body for burial.
Wongso was sentenced to 20 years in prison, and released last year having served just eight years and is still fighting to clear her name.
In 2021, also in Indonesia, a jilted lover named Nani Apriliani Nurjaman sent a package of spiked satay to her former boyfriend Yohanes Tomi Astanto.
The traditional Indonesian meal of meat cubes served on wooden skewers had also been laced with cyanide, although the ex-boyfriend refused to accept the suspicious package when it was delivered to his home by an online delivery driver.
In a tragic twist of fate, the delivery driver brought the food home to his family rather than waste it, where his wife and 10-year-old son ate it – killing the child and making the mother extremely ill.
In Hong Kong in 2003, investment banker Robert Kissel was killed by his wife, American expatriate Nancy Kissel, who was sentenced to life imprisonment for the murder which took place at the couple's luxury apartment.
Kissel laced her husband's strawberry milkshake with powerful sedatives (which are included in the FBI data under 'poison'), rendering him unconscious before bludgeoning him to death.
She then rolled his dead body in a carpet and dumped him in a storeroom.
At trial, Kissel claimed that her husband had been abusive to her and their two young children, and that she could not remember clubbing him to death with a metal statue after she poisoned him.
Rahmi Fauzi, a lecturer and psychologist who specialises in clinical and forensic psychology at Lambung Mangkurat University told news.com.au that poison is considered 'a neater' way to kill.
'Other weapons, such as knives or even guns, can require more power or strength, and there is a risk that the victim may not die and may be able to fight back and even overpower the perpetrator,' she said.
'Often, women want to commit murder without having to use physical strength or inflict direct injuries, even though poisoning can mean that the victim or victims are struggling for their lives for hours afterwards.'
She added that the way men and women face and react to direct conflict is different, which in turn can influence the way they murder.
'Men, when faced with conflict or when fighting, get a spike in adrenaline which drives them to face and get rid of the threat.
'For women, self defence is not physical, but about how they can stay safe or get themselves out of an unsafe situation.'
Fauzi also said that traditional roles of women as homemakers may make it easier for them to administer poison if they are in charge of regularly preparing meals, food and drinks for others and that they often use 'natural' poisons that are found in their environment.
'When we look at poisoning cases, we see that women tend to use poisons that are easily available to them, such as medicines like sleeping pills or other natural poisons like plants or vegetation.'