Investigating Root Causes of School Violence: A Case-Control Study of School Violence Offenders, Non-School Youth Violence Offenders, and Non-Offending Youths, United States, 1990-2020

This study investigated root causes of school shootings by using a case-control methodology to compare 157 adolescent school shooters (cases) to samples of two key comparison groups: 157 non-school adolescent shooting offenders and 157 non-offending youths who attended the same school as the school shooter (controls) in the United States between 1990 and 2020 (overall n=471). Specifically, the researchers compared:

Adolescent school shooters who committed shootings both fatal and non-fatal to
adolescents who committed shootings both fatal and non-fatal outside school grounds in the community.
Adolescent school shooters who committed homicide to adolescents who committed shooting homicides outside school grounds in the community.
Adolescent school shooters who caused non-fatal injuries to adolescents who committed non-fatal shootings with injuries outside school grounds in the community.
Adolescent school shooters to non-offending students from the same school.

All groups were compared on items theorized to be risk and protective factors to crime based on major criminology theories, such as social learning, general strain, social control, bio-social, life course, and psychology. Building upon the methodology used in The American School Shooting Study (TASSS), this study relied on open-source, content analysis research methods to obtain all publicly available information on the sampled individuals. Files were collected from over 60 databases, major search engines, and archival resources, which were then reviewed and coded by the research team for evidence of risk and protective factors.