This piece of research is designed to achieve the following: (1) to highlight the salient biopsychosocial factors shared amongst many of the perpetrators of this school shooting phenomenon; (2) to reveal many of the noteworthy environmental factors, both, within the assailant's school system and in his/her immediate environment; (3) to discuss the mental health histories and indicators of mental illness commonly associated with these perpetrators; and (4) to provide a cogent, statistically-supported rationale to explain how these identified variables may serve as predictive factors in leading an individual to committing a shooting at his or her school. In pursuit of this objective, the researchers utilized a methodology with two, distinct dimensions. This research begins with a critical review of the extant literature related to the modern school shooting phenomenon in the United States, a literature review, occurring between the years 1985 and 2020. Next, the second phase of our methodology undergoes a qualitative analysis of the identified factors and variables that have been consistently associated with the perpetrators of school shootings across the majority of research included in the critical review. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]