A case study is presented of a 22-year-old student mass murderer who stabbed or shot to death 6 college students and wounded 14 others. Because he left a lengthy autobiographical “manifesto” and social media posts, and an extensive law enforcement investigation ensued, a significant amount of information exists to examine the case. The assailant presents a complex diagnostic and psychodynamic picture, including likely features of autism spectrum disorder, narcissism, psychopathy, and depression. A predominant theme is the role of extreme social isolation and severe, pathological envy, fueling the eventual attacks. With the benefit of hindsight, prevention strategies are discussed, and the challenges in identifying and treating insidious, potentially destructive envy. Retrospective threat assessments of the subject on the WAVR-21 V3 (Workplace Assessment of Violence Risk, Version 3) are presented at 3 one-year intervals leading up to the mass murders as he traversed the pathway to predatory violence.