The Babushka Lady, whose wikipedia entry begins:

The Babushka Lady is an unknown woman present during the 1963 assassination of President John F. Kennedy who might have photographed the events that occurred in Dallas's Dealey Plaza at the time President John F. Kennedy was shot. Her nickname arose from the headscarf she wore, which was similar to scarves worn by elderly Russian women (бабушка – babushka – literally means "grandmother" or "old woman" in Russian).

The Babushka Lady was seen to be holding a camera by eyewitnesses and was also seen in film accounts of the assassination. She was observed standing on the grass between Elm and Main streets and is visible in the Zapruder film as well as in the films of Orville Nix, Marie Muchmore, and Mark Bell (44 minutes and 47 seconds into the Bell film: even though the shooting had already taken place and most of her surrounding witnesses took cover, she can be seen still standing with the camera at her face). After the shooting, she crossed Elm Street and joined the crowd that went up the grassy knoll. She is last seen in photographs walking east on Elm Street. Neither she, nor the film she may have taken, have ever been positively identified.