Common trends in workplace and schoolplace violence include the profiles of the perpetrators, the targets, the means, and the pathways to violence. Perpetrators are often described as "loners" with poor social skills who are often obsessed with violence and weapons. The targets of choice for both workplace and schoolplace violence include authority figures, women who have rejected them, and peers who are in conflict with them. The shared motive of the killers is revenge. Since experts have been studying effective means of dealing with workplace violence for the past 15 years, the prevention and intervention strategies derived from the studies can help law enforcement and school administrators develop a standard operating guide to avoid and respond to school place violence. Generally, police agencies should assume the same role in preventing schoolplace violence as they have with workplace violence, by becoming an integral part of the threat and violence assessment team. Preparation should involve team and policy development as well as emergency preparedness. Police should also train school personnel, students, and the community in how to identify threats and warning signs, de-escalate an agitated situation, and escape violence. Also discussed in this article are critical post-incident factors, the lessons learned from the Columbine school shootings, and the ripple effects of Columbine.