Amateur cameraman Abraham Zapruder captured the killing in Dallas in November 1963 on his eight-millimetre home movie camera. The images have helped launch a hundred conspiracy theories.
The original 26-second film is kept in a freezer in a federal archive, one of the most significant documents in US history.
Abraham Zapruder and his camera
The Zapruder family is arguing over exactly how much the film is worth. The federal government is offering them $3m, but they want $18m and are prepared to go to court, saying that they want to recoup the cost of preserving and enhancing the film.
While the wrangling continues, the Zapruders are releasing the video version, which is going on sale for $20 a copy.
The 45-minute video, called 'Image of an Assassination: A New
Look at the Zapruder Film,' consists of a 40-minute preamble and
six separate showings of President Kennedy's head exploding when
hit by a bullet.
BBC Correspondent Stephen Sackur says some Americans are questioning the motives of the Zapruder family and feel the film of the last seconds of President Kennedy's life is being misused.
Hordes of amateur cameramen tried to film the Kennedys in Dallas
Ali, executive producer for MPI Home Video, which made the video, argues that, despite being "gruesome, shocking and vulgar," it is probably
the most important film clip in the nation's history.
"Parents should be cautious about showing it to children under
the age of 11 because it is disturbing, but this needs to be out in
the hands of the people," he said.