Prior to the program's inception in 1971, confidential informants regularly refused to testify for fear of violent physical retribution. Since 1971, however, almost 5,500 principal witnesses plus their family members have accepted the protection offered by the program. At the heart of the program is a network of 160 specially trained Witness Security Inspectors stationed throughout the country whose sole responsibility is to protect and assist endangered witnesses; supporting these inspectors are 150 Deputy U.S. Marshals. The Witness Security Program training curriculum includes diverse courses ranging from psychological testing and counseling and methods of documentation to defensive driving and protection of high profile dignitaries. Field inspectors also attend semiannual training conferences to stay current with new policies and procedures. The Witness Security Program is considered a very successful operation, since information provided by protected witnesses has helped to convict approximately 89 percent of defendants against whom they have testified. Steps involved in protecting a witness are detailed.