Nearly a dozen people were taken into custody in and around Dealey Plaza in the minutes following the assassination.[51] In most of these instances, no records of the identities of those detained were kept.[52] The most famous of those taken into custody have come to be known as the "tramps": three men discovered in a boxcar in the rail yard west of the grassy knoll. Speculation regarding the identities of the three and their possible involvement in the assassination became widespread in the ensuing years. Photographs of the three at their time of arrest fueled this speculation, as the three "tramps" appeared to be well-dressed and clean-shaven, seemingly unlikely for hobos riding the rails. Some researchers also thought it suspicious that the Dallas police had quickly released the tramps from custody apparently without investigating whether they might have witnessed anything significant related to the assassination,[53] and that Dallas police claimed to have lost the records of their arrests[54] as well as their mugshots and fingerprints.



Charles Harrelson, the father of actor Woody Harrelson, has been alleged to be the tallest of the three tramps in the photographs. Harrelson at various times before his death boasted about his role as one of the tramps,[58] however, in a 1988 interview, he denied being in Dallas on the day of the assassination.[59]

E. Howard Hunt, the CIA station chief who was instrumental in the Bay of Pigs Invasion, and who later worked as one of President Richard Nixon's White House Plumbers, was alleged by some to be the oldest of the tramps. At the time of his death, Hunt's son released tapes of Hunt implicating LBJ in Kennedy's assassination.[60] In 1975, Hunt testified to the United States President's Commission on CIA activities within the United States that he was in Washington, D.C. on the day of the assassination. This testimony was confirmed by Hunt's family and a home employee of the Hunts.[61] In 1985 however, in Hunt's libel suit against Liberty Lobby, defense attorney Mark Lane introduced doubt as to Hunt's location on the day of the Kennedy assassination through depositions from David Atlee Phillips, Richard Helms, G. Gordon Liddy, Stansfield Turner, and Marita Lorenz, plus a cross-examination of Hunt.

Frank Sturgis is thought by some to be the tall tramp in the photographs. Like Hunt, Sturgis was involved both in the Bay of Pigs invasion and the Watergate burglary. In 1959, Sturgis became involved with Marita Lorenz, who later identified Sturgis as a gunman in the assassination.[62] Hunt's confessions before his death similarly implicates Sturgis.