Stills from the Zapruder film of the Kennedy assassination, 22 November 1963

A sequence of still images taken from Zapruder's Super-8 film was published by LIFE with the headline 'Split-second sequence as the bullet struck'. The amateur, grainy pictures have become fixed in the universal consciousness as the defining trace of a key moment in history. Yet their granular, hard-to decipher quality has made them curiously elusive as evidence and they have come to serve as metaphors for the ambiguities of the photographic medium. Individual frames have been appropriated as reference points by a number of artists, including Richard Hamilton, in their investigation of the mutability of visual documents. It is instructive -- in considering the relationship between record and allegory -- to situate Zapruder's stills in the context of Warhol's 'Death and Disaster' series of 1962-64 and his emotive silk-screens of Jackie Kennedy in mourning, derived from anonymous press images.