According to my friend, Gunnery Sergeant Carlos Hatchcock, the former senior instructor for the U.S. Marine Corps Sniper Instructor School at Quantico, Virginia, it could not be done as described by the FBI investigators. Gunny Hathcock, now retired [since deceased], is the most famous American military sniper in history. In Vietnam he was credited with 93 confirmed kills--and a total of over 300 actual kills counting those unconfirmed. He now conducts police SWAT team sniper schools across the country. When I called him to ask if he had seen the Zapruder film, he chuckled and cut me off. "Let me tell you what we did at Quantico," he began. "We reconstructed the whole thing: the angle, the range, the moving target, the time limit, the obstacles, everything. I don't know how many times we tried it, but we couldn't duplicate what the Warren Commission said Oswald did. Now if I can't do it, how in the world could a guy who was a non-qual on the rifle range and later only qualified 'marksman' do it?"
The Marines were not the only ones who attempted to duplicate the shots. According to Victor Ostrovsky, an Israeli Mossad agent, the Mossad also tried to reenact the shooting using the available data. Using their best marksmen and finest equipment, they also found it couldn't be done by one man, using that position, in the time allowed:
"To test their theory, they did a simulation exercise of the presidential cavalcade to see if expert marksmen with far better equipment than Oswald's could hit a moving target from the recorded distance of 88 yards. They couldn't. . .The Mossad had every film taken of the Dallas Assassination. Pictures of the area, the topography, aerial photographs, everything. Using mannequins, they duplicated the presidential cavalcade over and over again. Professionals will do a job in the same way. If I'm going to use a high powered rifle, there are very few places I'd work from, and ideally I'd want a place where I held the target for the longest possible time, where I could get closest to it, but still create the least disturbance. Based on that, we picked a few likely places, and we had more than one person doing the shooting from more than one angle. . . .During the simulation, the Mossad, using better, more powerful equipment, would aim their rifles, which were set up on tripods, and when the moment came they'd say "bang" over the loudspeakers and a laser direction-finder would show where the people in the car would have been hit, and the bullet exits. It was just an exercise, but it showed that it was impossible to do what Oswald was supposed to have done." 56 [Ostrovsky, Victor, and Hoy, Claire, By Way of Deception, New York: St. Martin's Press. 1990. pp. 141-143]