The criteria in effect prior to November 22, 1963, for determining whether to accept material for the PRS general files were broad and flexible. All material is and was desired, accepted, and filed if it indicated or tended to indicate that the safety of the President is or might be in danger, either at the present or in the future. * * * There are many actions, situations, and incidents that may indicate such potential danger. Some are specific, such as threats; danger may be implied from others, such as membership or activity in an organization which believes in assassination as a political weapon. All material received by PRS was separately screened and a determination made as to whether the information might indicate possible harm to the President. If the material was evaluated as indicating some potential danger to the President--no matter how small--it was indexed in the general PRS files under the name of the individual or group of individuals to whom that material related. 17

The general files of PRS consist of folders on individuals, card indexed by name. The files are manually maintained, without use of any automatic data-processing techniques. 18 At the time of the assassination, the active PRS general files. contained approximately 50,000 cases accumulated over a 20-year period,19 some of which included more than one individual. A case file was established if the information available suggested that the subject might be a danger to the President. Many of these cases were not investigated by PRS. The case file served merely as a repository for information until enough had accumulated to warrant an investigation.20 During the period November 1961 to November 1963, PRS investigated 34 newly established or reactivated cases concerning residents of Texas.21 Most of these cases involved persons who used threatening language in communications to or about the President. An additional 115 cases concerning Texas residents were established but not investigated.22

When PRS learns of an individual whose conduct warrants scrutiny, it requests an investigation by the closest Secret Service field office,23 of which there are 65 throughout the country. If the field office determines that the case should be subject to continuing review, PRS establishes a file which requires a checkup at least, every 6 months.24 This might involve a personal interview or interviews with members of the person's household. 25 Wherever possible, the Secret. Service arranges for the family and friends of the individual, and local law enforcement officials, to advise the field office if the subject displays signs of increased danger or plans to leave his home area. At the time of the assassination there were approximately 400 persons throughout the country who were subject to periodic review. 26

If PRS concludes after investigation that an individual presents a significant danger to the life of the President, his name is placed in a "trip index file" which is maintained on a geographical field office basis. 27 At the time of the assassination the names of about 100 persons were in this index, all of whom were included in the group of