This information provides a brief, summary outline of how investigators should assess anonymous bomb threats at schools. Applying these principles may help administrators and law enforcement personnel accurately assess the viability and credibility of a threat and appropriately gauge their response. Any credible evidence provided by teachers or peers that one or more students are planning a mass homicide of their schoolmates and teachers needs to be assessed with different measures and afforded a graver concern than the more typical anonymous bomb threat. (Contains 1 footnote.)