Journal of Threat Assessment and Management, Vol 13(1), Mar 2026, 37-60; doi:10.1037/tam0000250
Motivation is at the heart of understanding the causes and reasons for all human behavior. This article addresses the often elusive, conflated, or overlooked motivational underpinnings of lone actor grievance-fueled violence, referring to acts of demonstrative violence carried out by a single perpetrator, for example, lone actor terrorism, school shootings, or public rampage violence. With the frequent occurrence of such violence over the past decades and the ongoing efforts to intervene and prevent attacks before they occur, it becomes essential to understand lone actors and the factors and mechanisms motivating their behavior. The present article outlines a conceptual understanding of motivation, proposing that behavior is driven by the desire to fulfill or restore basic psychological needs, for example, belonging, identity, or significance. Alongside this, the role of individual characteristics in offending is examined, outlining the importance of questions and formulation in understanding motivation. The study illustrates the analytical and practical utility of psychological needs, questioning, and formulation in understanding offending behavior and motivation through an in-depth case analysis of the 2020 Nova Scotia attack perpetrated by Gabriel Wortman. The case analysis focuses on two central questions, (a) “what was it about Wortman and his situational circumstances that led him to commit violence?” and (b) “how was the violence a means to restore or resolve thwarted psychological needs?” The article concludes by reviewing the importance of paying greater attention to motivation and discusses the benefits that this provides to preventative efforts made by law enforcement, threat assessment teams, and mental health practitioners. (PsycInfo Database Record (c) 2026 APA, all rights reserved)