German Mass Murderers and Their Proximal Warning Behaviors




Zentraler Phänomenbezug

Allwinn, Mirko; Hoffmann, Jens; Meloy, Reid John

1. Januar 2019
1. Januar 2021

Radikalisierung (allgemein)
Phänomenübergreifend, Phänomenunspezifisch (kein ausdrücklich ausgewiesener Phänomen- bzw. ideologischer Bezug

Zentrale Fragestellung:

The main objective of this study was to analyze mass murder cases committed by adults from a threat assessment perspective, and to identify risk factors and proximal warning behaviors. Therefore, court records of 33 German mass murderers between 2000 and 2012 were systematically evaluated. One major focus was the comparison between psychotic and nonpsychotic offenders. Significant differences were found between the 2 groups regarding their choice of weapons, planning behavior, personal crises, personality aspects, and warning behaviors.

Stichprobenbildung – Datenzugang:
We identified relevant cases for this study inGermany in two steps. First, a media databasesearch for the identification of potential adultmass murder cases was carried out. In a secondstep, the full case files for all identified attackswere requested. Of the 60 cases identified, 43case files (72%) were sent to us by the publicprosecution departments throughout Germany.Cases for the study were selected based uponthe following criteria: 1. the attack was carried out between January 1, 2000 and December 31, 2012, and 2. at least partially happened in public space. 3. The perpetrator was older than 24 years. 4. The perpetrator had tried to kill more thanone person. 5. Killings in the context of organized crime,or attacks carried out by members of ter-rorist organizations, as well as attackscommitted using only vehicles were excluded

Inhaltlicher / Thematischer / Empirischer Zentralfokus

n = 33
Deskriptivanalyse, Bivariante Verfahren


Zentrale Forschungsbefunde:

Significant differences were found between the 2 groups regarding their choice of weapons, planning behavior, personal crises, personality aspects, and warning behaviors. Nonpsychotic subjects were significantly more likely to evidence pathway warning behavior and directly threaten their targets before the attack when compared with the psychotic subjects. Effect sizes were medium to large. All offenders showed multiple proximal warning behaviors prior to their attacks. Findings are interpreted in light of previous studies and for the purpose of enhancing threat assessment protocols of such persons of concern.

Implikationen oder praktische Verwendbarkeiten:

The study reveals the presence of warning signs in a representative sample of adult German mass murderers and relates the results to the research from the United States. A predisposition to commit an act of deadly violence was noticeable months, years, or even decades in advance in most of the cases, but the specific intent became apparent relatively late in the pathway toward violence, usually within days or weeks before the killings. The work of threat assessment professionals is supported by the study and opportunities for preventing severe violence are identified.

Hinweise / Anregungen zu möglicher Anschlussforschung:


Zitation des Projekts

  • Allwinn, M., Hoffmann, J., & Meloy, J. R. (2019).
    German mass murderers and their proximal warning behaviors. Journal of Threat Assessment and Management, 6(1), 1–22.

Quellenangabe projektbezogener Publikation