The challenge of preventing spree killings

BMJ 2012; 345 doi: https://doi.org/10.1136/bmj.e8603 (Published 19 December 2012) Cite this as: BMJ 2012;345:e8603
  1. John H M Crichton, consultant forensic psychiatrist
  1. 1Orchard Clinic, Royal Edinburgh Hospital, Edinburgh EH10 5HF, UK
  1. john.crichton{at}nhslothian.scot.nhs.uk

We know something about who perpetrates them and why, but not how to prevent them

The tragic shooting in Newtown, Connecticut on 14 December raises recurring questions. Who commits such atrocities and why? How can they be prevented? Despite their seemingly regular occurrence in the United States, the relative rarity of spree killings challenges attempts to understand them scientifically. Yet broad themes emerge if we examine published non-randomized samples that may help answer such questions.

Mass, or multiple, homicide has been defined as a single incident in which five or more victims are injured, at least three of them fatally.1 Mass murderers have been categorized according to their style: family annihilators, disciple murders, pseudo-commanders, disgruntled employees, and set and run killers.2 The events themselves can be divided into instrumental killings, victim specific killings, and massacres.3 Massacres are indiscriminate killings where victims are chosen by chance, situation, or peripheral affiliation. The autogenic massacre, which is distinct from the civil or military massacre, is carried out by an individual (or very occasionally more than one individual), serves the idiosyncratic purposes of the perpetrator, and may follow initial victim specific killing.3 The recent massacre in Newtown follows that pattern.

Two case series that examined mass murders in the US and Canada over 49 years identified 30 adult firearm perpetrators and 34 adolescent ones.4 5 All were male (table). One in 10 adult perpetrators had schizophrenia, and the precipitating event seemed to be a work problem in 50% of cases and a relationship problem in 23%. About 60% of the adult perpetrators committed suicide or were killed by police at the end of the incident. The authors concluded that the adult perpetrators were largely angry isolated men who were unhappy with their lot, devoid of any affection or bonds, and who typically had a preoccupation with weapons.

Characteristics of mass murderers in the United States and Canada4 5

View this table:

The fact that most perpetrators lose their own lives frustrates attempts to understand motivation. Mullen tried to distinguish people at risk of spree killing from the many angry, disappointed, isolated young men who may think of suicide but don’t perpetrate mass murder.3 He described the characteristics of five perpetrators or attempted perpetrators he had assessed. Most of them had not previously perpetrated violence or been in contact with mental health services. They were resentful, obsessional young men without intimate relationships, who were bullied as children and socially isolated as adults. They were outside of the workforce and involved with guns or military activity (or both), or they had survivalist interests. They were self absorbed and described fantasies of killing. All had intended the event to end with their own death. Many were mimicking other shooters. Mullen’s conceptualization of the autogenic massacre as a planned non-specific act of revenge directed at the uncaring world, often seeking infamy and culminating in the perpetrator’s death, usually by suicide, preceded the 2011 massacre in Norway, which perhaps marked the emergence of an alternative fantasised ending—grandstanding at a trial.6

So published research provides some indication of the who and the why, but how can we prevent such events? Although the available evidence suggests some recognizable characteristics of perpetrators, it is not possible to use such common characteristics to screen or profile potential killers because events are so rare.

The lethality of the attack is associated with the type of weapon used. Attacks with knives or swords may have similar intent but do not match firearms for their lethality. A knife attack at a school in central China almost coincided with the Newtown killings, and although 22 children were wounded in the Chinese incident none was killed.7

In North America debate centres around the extent to which gun purchase and possession should be regulated. The association between gun ownership and homicide rates is not straightforward, but restriction of the ownership and purchase of guns by law in Australia has been associated with a reduction in the overall homicide rate.8

Although mass murder is not new, easy acquisition of particularly lethal firearms and modern trends in reporting have created a new context for the problem. Successful public health strategies to reduce suicide have focused on measures to impede easy suicide, such as limiting the amount of paracetamol (acetaminophen) that can be purchased at a single shop.9 Perhaps the most successful intervention to reduce autogenic massacres may be simply to make them more difficult to carry out, although their rarity may mean we will never know whether any intervention is successful. America seems to have a choice: to secure every childcare facility against the possibility of attack or reconsider the ease with which semi-automatic weapons find their way into the hands of troubled young men.


Cite this as: BMJ 2012;345:e8603


  • Competing interests: The author has completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declares: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; JHMC was vice chairperson of the National Confidential Inquiry into Homicides and Suicides steering group, he has been a member of several Scottish government expert committees involving risk and the public.

  • Provenance and peer review: Not commissioned; externally peer reviewed.


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