Table 3.
Frequencies of Motivating Factors among U.S.-Based Mass-Shooters versus Non-U.S.-Based Mass-Shooters
| U.S.-Based (n=835) | Non-U.S.-Based (n=350) | ||||
|---|---|---|---|---|---|
| Motivating Factor | n | % | n | % | p |
| Self-Survival | 7 | 0.84 | 4 | 1.14 | 0.740 |
| Criminal Objectives | 213 | 25.51 | 30 | 8.57 | <.001 |
| Religious or Political Beliefs | 32 | 3.83 | 39 | 11.14 | <.001 |
| Psychosis/Other Severe Psychiatric Disturbance | 40 | 4.79 | 13 | 3.71 | 0.414 |
| Emotional Upset | 482 | 57.72 | 228 | 65.14 | 0.017 |
| Sub Types of “Emotional Upset” | |||||
| Type 1: Despair or extreme sadness over life event(s) | 77 | 15.98 | 22 | 9.65 | 0.023 |
| Type 2: Disgruntled employee | 32 | 6.64 | 10 | 4.39 | 0.235 |
| Type 3: Disgruntled student | 4 | 0.83 | 2 | 0.88 | 1.000 |
| Type 4: Family/marital/custody dispute (non-impulsive in nature) | 38 | 7.88 | 4 | 1.75 | <.001 |
| Type 5: Overwhelming, impulsive anger | 122 | 25.31 | 69 | 30.26 | 0.165 |
| Type 6: Revenge for bullying | 4 | 0.83 | 15 | 6.58 | <.001 |
| Type 7: Romantic rejection or loss/severe jealousy | 102 | 21.16 | 40 | 17.54 | 0.260 |
| Type 8: Social/peer rejection (e.g., feeling isolated or unwanted, not necessarily involving bullying) | 10 | 2.07 | 4 | 1.75 | 1.000 |
| Type 9: Specific non-romantic grudge | 93 | 19.29 | 62 | 27.19 | 0.017 |
| Related to Psychopathic or Sadistic Traits | 17 | 2.04 | 7 | 2.00 | 0.968 |
| Related to Narcissistic Traits | 4 | 0.48 | 2 | 0.57 | 1.000 |
| Related to Schizoid/Autistic Detachment | 3 | 0.36 | 2 | 0.57 | 0.635 |
| Disorganization Related to Severe Psychiatric Disturbance | 16 | 1.92 | 11 | 3.14 | 0.197 |
| Disorganization Related to Drug or Alcohol Intoxication | 8 | 0.96 | 7 | 2.00 | 0.143 |
| Unknown/No Determinable Motive | 13 | 1.56 | 7 | 2.00 | 0.589 |
*
P-values are derived from chi-square tests comparing each row with the rest of the sample. For comparisons with any cell values<5, Fishers Exact Test is used.