Eyewitnesses saw Oswald in the window of the TSBD as he was doing the shooting; several co-workers were directly below him as he fired - they heard the shots right over their head and heard the shell casings drop on the floor. No credible witness saw any other shooter in Dealey Plaza, nor has any concrete evidence ever been found of a fourth shot or a second shooter. (Posner demolishes the contradictory and evolving testimony of many of the "witnesses" who formed the basis for the film "JFK"; he also analyzes and explains the head movements etc. shown in the Zapruder film.)
Eyewitnesses saw Oswald in the window of the TSBD as he was doing the shooting; several co-workers were directly below him as he fired - they heard the shots right over their head and heard the shell casings drop on the floor. I won't pretend to have any answers, but I have a whole lot of questions. Maybe they might seem "irrelavent" to some people, but details are my job, so I guess I'm just wired that way....
One thing that just doesn't seem right...there were three shell casings found by the window on the 6th floor by the open window. Oswald was supposed to have fired three shots in about 8 seconds, stash the gun, and get the hell out of there. If he was in such a hurry, and knew that his third shot took the president's head off, why did he bother to eject the third spent shell casing?