Characteristics of family killers revealed: The male dominated crime most common in August

"Family annihilators have received little attention as a separate category of killer," said Professor David Wilson, one of the paper's three authors, and Director of the Centre of Applied Criminology at Birmingham City University. "Often they are treated like spree or serial murderers, a view which presupposes traits, such as the idea that the murderer 'snaps', or that after killing their partner or children the killer may force a stand-off with the police."

Using newspaper archives to analyse three decades of family annihilation, from 1980 to 2012, the paper's authors identify shared characteristics of the killers, but four different types. Newspapers acted as an invaluable source of information as very few of these 'family annihilators' had criminal records or were known to mental health services beforehand. Some were serving police officers.

The paper reveals the first composite picture of family annihilators, revealing trends such as gender, age, motivation and even the most likely month and day that a man will annihilate his family.

"The clearest unifying factor is that this is overwhelmingly a male crime. While 71 family annihilators were identified, 59 were male," said Professor Wilson. "We also found that the rate at which this type of crime is being committed has increased, with the first decade of the 21st century claiming over half of all cases."

Over half of these men, 55%, were in their thirties; 10% were in their twenties and the oldest was discovered to be 59.

August was found to be the most common month for the killing to take place, accounting for 20% of cases. Just under half of all murders were committed over weekends, especially on a Sunday.

"This is partly because the father had access to his children in the middle of the school holidays when he is not at work," said Wilson. "There may also be a symbolic factor as estranged fathers know that by the end of the weekend they will have to hand their children back to the mother."

81% of the men attempted suicide after the act, which refutes the traditional idea that family annihilators may force the police to shoot them, as is common with spree murderers. There were no recorded cases of stand-offs with the law.

Also refuted is the idea that murderers may be unhappy or frustrated men with a long life history of failure. Some had been highly successful in their careers before the murder. 71% were employed, with occupations ranged from surgeons and marketing executives, to postmen, police and lorry drivers.

Stabbings and carbon monoxide poisoning were statistically the most common murder methods, while the majority of murders were found to take place in the home.

The team also considered the stated motivations of the killers, either pieced together by interviews with relatives or made apparent with suicide notes read at coroner's inquests.

Family breakup was the most common cause, accounting for 66% of cases, although this included related domestic issues such as access to children. Financial difficulties were the second most commonly cited motive; followed by honour killing and mental illness.

"Analysing these shared traits and motivations has allowed us to identify four types of killer; anomic, disappointed, paranoid and self- righteous," said Prof. Wilson. "While these may overlap, they all go beyond the traditional ideas of the 'revenge' or 'altruistic' murderers."

Categorizing the Killers: Four Types of Family Annihilator

Self-righteous: The killer seeks to locate blame for his crimes upon the mother who he holds responsible for the breakdown of the family. This may involve the killer phoning his partner before the murder to explain what he is about to do. For these men, their breadwinner status is central to their idea of the ideal family.

Disappointed: This killer believes his family has let him down or has acted in ways to undermine or destroy his vision of ideal family life. An example may be disappointment that children are not following the traditional religious or cultural customs of the father.

Anomic: In these cases the family has become firmly linked in the mind of the killer to the economy. The father sees family as the result of his economic success, allowing him to display his achievements. However, if the father becomes an economic failure, he sees the family as no longer serving this function.

Paranoid: Those who perceive an external threat to the family. This is often social services or the legal system, which the father fears will side against him and take away the children. Here the murder is motivated by a twisted desire to protect the family.

In all of these cases masculinity and perceptions of power sets the background for the crimes. The family role of the father is central to their ideas of masculinity and the murders represent a last ditch attempt to perform a masculine role.

"The family annihilator should be seen as a specific category of murderer, for a crime which appears to be increasing," concluded Wilson. "To begin solving this problem the role of gender must be recognised, acknowledging that it is mainly men who will resort to this type of violence."