The dialogue surrounding couples in which a homicide takes place often focuses on a history of domestic violence within the relationship, rather than the reasons the offender killed their partner. The importance of domestic violence notwithstanding, why do people sometimes kill the ones they love?

The latest figures show that of the 479 homicides committed in Australia between 2010 and 2012, 39% (187 incidents) were classified as domestic. Of those, 58% (109 incidents) were within an intimate relationship.

There are numerousexamples of intimate partner homicide where there is no evidence of previous domestic violence. So, why might a homicide occur in an otherwise seemingly non-violent relationship?

One of the authors’ (Belinda’s) recent study looked at 149 Australian homicides to determine who kills who and for what reason.

The interactive below shows how many cases involving each relationship type (such as intimate partners and strangers) fell into the various motive categories. The most-common reason for intimate partner homicide was jealousy, followed by gain, and then love.

Jealousy

Jealousy homicides involve an offender thinking they are at risk of losing their partner to someone else. Either the offender’s lover or their rival may be the target in these homicides.

Jealousy accounted for the largest number of the intimate partner homicides that were examined in the study (40%). These jealousy cases all included husbands who killed their wives. In court documents for these cases, jealous rage or morbid jealousy were often blamed for spurring the murders.

While there was prior abuse in some of these cases, not all were characterised by domestic violence. In some cases, the perpetrator lashed out with lethal violence, despite being previously non-violent.

Nine of the 12 victims were stabbed or beaten to death.

These types of attacks speak to the frenzied and emotional nature of jealousy motives, even for those who usually do not commit domestic violence.

Gain

The second-most-common motive for the intimate partner homicides studied was gain (23%).

In these cases, the primary reason for the homicide was to acquire some personal and tangible benefit. These victims were killed because they had something the offender wanted, such as money or property.

In contrast to the jealousy homicides, gain homicides were more often committed or solicited by females. Those that involved females (five out of seven cases) were committed for financial gain either because the woman wanted an insurance payout and assets, or because they thought they were going to be cut out of wills following a divorce.

Importantly in these cases, there was no prior abuse from the women’s husbands. This finding goes against how we often view female killers, because they were not a reaction to domestic violence. Perhaps it reflects that females traditionally have less financial security at retirement due to lower earnings, maternity leave, and other lifetime circumstances.

For some women, the feeling of entitlement and the need to financially secure themselves and their family may develop into a heightened risk for their male partners during divorce.

Love

Finally, homicides motivated by love are committed so the offender can remove a person they love from a situation they believe to be “worse than death”. This can manifest in two ways.

Altruistic homicides may involve an offender perceiving the situation to be so bad that they would rather see the victim die than be alive to experience it. Alternatively, homicides perpetrated by assisting a loved one to commit suicide may also be motivated by love (these are very rare in Australia).

Love homicides accounted for 17% of the homicides examined in the study. Unsurprisingly, they often involved older couples. The victims in these homicides were usually very sick, suffering from chronic physical and mental illnesses. The most common cause of death in love homicides was poison.

Four of the five love homicides were committed by husbands who killed their wives. This is in contrast to love homicides committed outside of intimate partnerships, such as the killing of a child (filicide), where a female offender was more likely to be involved.

In the love homicides involving couples, none had a history of domestic violence.

The National Sexual Assault, Family & Domestic Violence Counselling Line – 1800 RESPECT (1800 737 732) – is available 24 hours a day, seven days a week for any Australian who has experienced, or is at risk of, family and domestic violence and/or sexual assault.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.