(1) David Healy, Technical Aspects of Film Alteration, included in The Great Zapruder Film Hoax (2003)

My interest in this has endured for some time now. I first saw the Zapruder film around the Geraldo showing in 1975. It was a bootleg copy that some cameraman had come across. The first time I saw it, perhaps five or six other television cameramen were with me and, to a man, we felt it was very peculiar.

Every man in the room had combat-zone camera experience and their comments can be summed up as follows: either Zapruder knew what was coming down or he was stone-cold deaf. Anyone who was unaware of what was about to transpire and was forward of any muzzle blast - especially within 50 feet to his rear, as he reported - would have been off that pedestal in a flash.

My knee-jerk summation of the Zapruder film? JFK had to have been shot by more than one rifle and from more than one direction - possibly three directions, but certainly at least two. I don't give much credence to the so-called jet effect.

My more considered opinion? At least two guns from the rear, where, at my gut level, I surmise two from the right rear and one from the front, probably as an insurance policy (from the limo driver's front-facing perspective).