John Costella was born in Australia. After graduating with honors degrees in both electrical engineering and the sciences from the University of Melbourne, he completed a Ph.D. in theoretical physics. After three years of postdoctoral research and lecturing at the University of Melbourne he was appointed as a teacher of Mathematics, Physics and Information Technology at Mentone Grammar.
Costella has researched the assassination of John F. Kennedy and has undertaken a sophisticated analyses of the Zapruder Film. Two of his articles, A Scientist's Verdict: The Film is a Fabrication and Mary Moorman and Her Polaroids appeared in The Great Zapruder Film Hoax (edited by James H. Fetzer).
In the wider context of the assassination, the most incongruous feature of the extant "Zapruder" film is arguably the depiction of a single, fatal shot to the President's head, which appears to blow out the entire right temple area, leaving a massive "crater".
The obvious inconsistencies between this imagery and the wounds to the President when he arrived at Parkland Hospital are enough to convince any serious student of the assassination that this section of the film is a complete fabrication. (Author David Lifton seems to be the first person to have made this observation in print, in his 1980 book Best Evidence.) But even leaving aside this "medical" evidence of alteration, the film itself can be examined for physical inconsistencies that would not occur if it were genuine, but which may have been overlooked if created as a work of "special effects". The "explosion" in Frame 313.
The bright red "explosion" shown in Frame 313 of the extant film appears to be a completely spurious addition. Recall that this "explosion" is not a ball of flame (as it would be if it were a special effect for an action movie), but rather is supposed to represent bloody matter ejected from the President's head. Now, whereas flame is caused by the emission of light upon the combustion of some material (which will subside when the fuel is spent), the red "spray" shown in Frame 313 ostensibly represents the reflection of light from the bloody matter, which would persist while this matter remains in the field of view.
Jean (Hill) calls to JFK - looking down into the middle of the seat - as he approaches them. He turns, and perhaps starts to wave. Mary (Moorman) snaps a photo and then the first shot hits him. He jumps, and starts to slump forward. Jackie then responds, and cries out, as Jean and Mary reported. The limo stops somewhere down past the steps. There are then anywhere from two to seven further shots, that inflict the remaining wounds to JFK and Connally Jean sees the hair on the back of JFK's head flap up as his skull is blasted out. The limo speeds off. Mary is quickly intercepted and asked for her photos. She and Jean undergo hours of interrogation, after which they finally turn over the Polaroids. And the cover-up begins.