"Ensuring the continuous operation of government and the safety of the personnel and citizens who enter government facilities on a daily basis is an essential part of securing our homeland. To enhance prevention efforts in this area, the U.S. Secret Service National Threat Assessment Center studied 43 attacks targeting federal government facilities and officials that occurred between 2001 and 2013 in the United States. These attacks bear an unfortunate resemblance to incidents of violence we see occurring in schools, colleges and universities, workplaces, and other public venues across the country. For example, most of the attacks were committed by lone actors, involved the use of firearms, and ended without law enforcement intervention. Further, although the offenders directed their attacks toward federal sites and officials, at times, the indiscriminant nature of their violence affected individuals who happened to be conducting business at government sites, attending government functions, or working in buildings shared with government personnel. This report builds on existing best practices that the U.S. Secret Service has established in the field of threat assessment by offering considerations for investigations, security practices, and other types of mitigation strategies to reduce the risk of incidents of targeted violence."
U.S. Secret Service: http://www.secretservice.gov/