Targeted violence, including mass shootings, are an urgent concern in the United States. Extensive research has been conducted to understand how to prevent mass shootings in public settings, in-cluding schools. While progress has been made identifying the behavioral and experiential factors that facilitate targeted violence offenders’ escalation towards violence, there is a lack of research that explicitly examines the relationship between trauma and targeted violence offender behavior. When trauma is acknowledged, it is relegated to childhood trauma in the home. To gain a more comprehensive understanding of the role trauma plays in the current research focused on mass shooters, this dissertation begins with a scoping review of the mass shooter literature from 1990 to the present. The results of this scoping review, which are focused on trauma-related frameworks and trauma-related outcomes, suggest that trauma plays a more complex and varied role in shoot-ers’ lives, behaviors, and motivations. This is followed by a thematic analysis of targeted violence offenders’ (N =12) self-authored documents that employs Cumulative Strain Theory (CST; Levin & Madfis, 2009) and Bronfenbrenner’s Ecological Systems Theory (1994; 2006) to analyze how individuals who have engaged in targeted violence 1) describe life events or circumstances in rela-tion to their behavior and plans to carry out a violent attack and; 2) how those descriptions align with current conceptions of trauma. Inductive-deductive data analyses confirmed that offenders are exposed to trauma across settings, as well as the three types of strain associated with CST. In addi-tion, shooters personally identified with other shooters based on the negative life events they expe-rienced, and the collective injustices described by violent extremist ideologies. Finally, contrary to previous research, shooters described the presence of protective factors. These results provide a deeper understanding of the role of trauma in the lives of those who carry out acts of targeted vio-lence and will aid in further specifying the role trauma informed care should play in targeted vio-lence intervention and prevention efforts.