DSS also conducts counterterrorism , counterintelligence , cybersecurity and criminal investigations domestically and abroad. Originating in diplomatic security measures implemented during the First World War , DSS was formally established in following the deadly bombings of the U. The service's most visible activity is providing security to the U.
As part of its duty to provide a safe and secure environment for U. While best known for its security role, DSS is a full-fledged law enforcement agency that conducts international criminal investigations , threat analysis , counterterrorism , counterintelligence , security technology, and cybersecurity.
The agency employs over 2, Foreign Service specialists, including special agents, security engineering officers, security technical specialists, and diplomatic couriers.
Whereas most U. DSS agents are unique in being required to serve multiple-year tours abroad as a condition of employment. When not on an overseas assignment, agents serve at DSS headquarters in Arlington, Virginia , or in one of the thirty-three field offices nationwide. A small percentage of DSS special agents are members of the State Department 's civil service and are not mandated to serve tours overseas; they instead focus on criminal investigations and dignitary protection within the United States.
When assigned to domestic field offices, DSS special agents investigate transnational crimes, passport fraud and visa fraud , and protect visiting foreign dignitaries. They also investigate the activities of foreign intelligence agencies that are focused on the Department of State, assist in apprehending fugitives that have fled the United States, and conduct background checks on State Department employees, applicants and contractors.
