The document focuses on violence committed by non-strangers (e.g., coworkers, bosses, clients, and domestic partners) within a common worksite. The guidelines can be used as benchmarks for helping assess the state of an organization's current policies and practices. Guidelines for employers are presented under four categories: pre-incident violence prevention and preparation, addressing violent or threatening incidents, managing the aftermath of an incident, and legal obligations and duties of employers. Guidelines for pre-incident violence prevention and preparation address such issues as pre-employment screening, use of community resources, development and review of security procedures, improvement of internal/external communications, and employee and manager training. Guidelines for addressing violent or threatening incidents focus on the use of all available resources and the evaluation of security after a threat. Guidelines for law enforcement agencies are presented under the following categories: pre-incident violence prevention and preparation, in-progress violent or threatening incidents, and managing the aftermath of an incident. Six suggestions are offered for where to obtain additional information.