In the past 20 years, schools have been increasingly exposed to school shootings in which many of the victims are targeted at random. Despite recent progress in coping with school crises such as suicide, accidental death, and targeted violence, the advent of random-type school shootings has left mental health, education, law enforcement, and other professionals struggling to deal with this type of traumatic event in terms of its aftermath and its prevention. In this chapter, a systems-oriented approach—rather than an individually-focused approach to traumatic events—the Traumatic Event Systems (TES) model, is proposed to increase the understanding and the effectiveness of professionals in responding to the aftermath of school shootings. The companion model, the Violence Threat Risk Assessment (VTRA), is proposed with a trauma-informed threat assessment practice that creates a nexus between prior trauma and future violence potential through an understanding of the “trauma-violence continuum.”