the authority to provide protection for foreign heads of state and was the lead agency for this role through the early 1970s. However, an order signed by President Richard Nixon gave primary responsibility of protection of visiting heads of state to the Secret Service. Nevertheless, the DSS has expanded its protection mission, including providing security to the heads of Afghanistan, Haiti and Liberia in their respective home countries. The appointment of Hillary Clinton as Secretary of State raised questions about whether DSS would serve its usual protective role, since, as a former First Lady, she received Secret Service protection. The DSS was ultimately named as the lead agency to carry out the protection for Hillary Clinton during her tenure as Secretary of State. Investigations DSS investigations, carried out by numerous Field Offices and Resident Agent offices throughout the U.S, and by RSOs overseas, focus mainly on passport or visa fraud. DSS Special Agents also investigate such cases as human and sex trafficking, document fraud, international parental kidnapping, violations of the Protect Act, assaults on federally protected persons, fugitive arrests overseas (with host nation assistance), counterterrorism and counterintelligence (CI) investigations and international organized crime cases. If there is a nexus to passport and/or visa fraud, use of State Department documents, diplomatic activities, the U.S. Foreign Service, or terrorism, DSS is typically involved. Passport and visa fraud U.S. passports and visas are valuable travel documents, and consequently some foreign nationals fraudulently acquire U.S. passports and visas to carry out criminal activities, including terrorism, inside the borders of the United States. It is a federal offense to apply, or assist someone in applying, for a U.S. passport or visa when they are not entitled to one. Usually this means an alien in the U.S. trying to establish a false U.S. identity, or stealing the identity from an American, often one who has died. Visa fraud can also include participating in sham marriages in order to allow an unentitled foreigner to become a U.S. citizen. Sometimes Americans, including Foreign Service Officers (FSOs), are the target of DSS investigations, such as an FSO selling visas for personal gain. DSS also investigates other alleged improper or illegal behavior by Department of State personnel, to include incidents of espionage. Such cases would involve other agencies, such as the Department of Justice. Overseas DSS must take the role of local and state law enforcement when investigating issues such