the use of sensitive investigative techniques such as the operation of confidential sources, undercover operations, and electronic surveillance. The FBI also furnishes on-the-job assistance to governments who request help during particularly difficult or sensitive investigations. Counterterrorism and military assistance DOD supplies a limited amount of military training and assistance to police officials. During fiscal years 1986 and 1987, DOD trained and equipped the El Salvadoran and Honduran police to counter urban terrorist activities. This assistance was authorized in response to the murder of U.S. Marines by terrorists in El Salvador and was managed and delivered by the U.S. Army Military Police. The assistance consisted of training in counterterrorism techniques and the supply of police vehicles, communications, weapons, and other equipment. This effort cost $19.8 million, of which $17 million was provided to El Salvador. In fiscal year 1990, DOD spent $6.4 million in previously authorized but unused military assistance funds to purchase needed equipment and weapons for Panama's newly formed national police force. Items procured included police vehicles, communications equipment, small arms, and personal gear. This assistance was a one-time, emergency program. DOD has an ongoing military assistance program to support Costa Rican police. In fiscal year 1990, DOD supplied $431,000 in military equipment and $232,000 in military training to the Costa Rican Civil Guard to help them carry out their responsibility to protect the country's border regions. DOD provided equipment such as vehicles, personnel gear, and radios, and military training in areas such as coastal operations. Additionally, DOD conducted technical training courses in equipment maintenance and medical skills among others. DOD, along with the United Kingdom, supports the Eastern Caribbean Regional Security System that was formed after the U.S. intervention in Grenada. The Security System is composed of a few permanently assigned military officers, but largely depends upon island nation police officers who can be called up for military duty in case of emergency. The United States equips and trains these personnel to prepare them for such an eventually. In fiscal year 1990, DOD provided $4.2 million in military assistance funds that were used to purchase equipment such as jeeps, small arms, uniforms, and communications gear. DOD also provided $300,000 for training in special operations, rural patrol, field survival, surveillance, and technical courses in communications, navigation, maintenance, and medicine. Difficulties in determining cost and extent of assistance Since some agencies fund assistance out of their own budgets, without necessarily