Who lives, who dies, who decides: Differences between mass public shooters who survive, are killed, and commit suicide

Abstract

This study provides an in-depth analysis of American mass public shooting conclusions between 1966 and 2017. Specifically, this work examines differences in factors contributing to the perpetrator's likelihood of surviving, being killed, and committing suicide. Ten hypotheses, rooted in previous homicide, suicide, homicide-suicide, and mass public shooting literature consider different psychological, situational, and background factors shaping the outcome of mass public shootings. Significant findings indicate factors influencing perpetrators' suicide include suicidal ideation, higher victim counts, and suicide copycat effects. Factors influencing perpetrators being killed similarly include higher victim counts, the arrival of law enforcement, lethal/non-lethal resistance, and government targets. This investigation provides practical implications for practitioners and policymakers, especially law enforcement and mental health practitioners, seeking to develop intervention and prevention strategies for addressing suicidal ideation and its most lethal outcome: mass public shootings.

A classification of combined homicide‐suicide: An update—Part III: Extrafamilial homicide‐suicide

“…Those with higher victim counts also distinguished those who were killed from those who survived. Being killed was also associated with arrival of law enforcement, resistance, and government targets, the latter presumably due to increased security [44]. In comparing with our study, it would appear that the larger the victim count (10 or more homicides for massacre homicides), differences between the groups dissolve, although history of suicidal ideation may simply have not been accessed uniformly.…”

“…Capellan and colleagues [44] trichotomized as we did, and found that those who committed suicide were associated with suicidal ideation, higher numbers of victims, and evidence of suicide imitation of others. Those with higher victim counts also distinguished those who were killed from those who survived.…”

“…Lankford dichotomized those who died, whether by suicide or having been killed, and found that older age, use of more weapons, and having killed more victims were significantly associated with the group that died [43]. Capellan and colleagues [44] trichotomized as we did, and found that those who committed suicide were associated with suicidal ideation, higher numbers of victims, and evidence of suicide imitation of others. Those with higher victim counts also distinguished those who were killed from those who survived.…”

A classification of combined homicide‐suicide: An update—Part I: Introduction and psychopathology

“…According to Duntley and Buss [4], “homicide ideation is part of an evolved psychological process that functions to mobilize attention, rehearse scenarios where homicide is a behavioral option, calculate the consequences of it, and motivate behavior” [2, p. 555]. Suicidal ideation is significantly associated with completed suicide: Relevant to homicide‐suicide, in mass public shooters suicidal ideation is associated with perpetrators who take their own lives in contrast to those interdicted, shot and killed by law enforcement [5].…”