A two-hour special on the event is scheduled to air Nov. 20, two days before the 40th anniversary of president John F. Kennedy's killing.
"It leaves no room for doubt," said Tom Yellin, executive producer of the special, narrated by Peter Jennings. He called the results of ABC's study "enormously powerful. It's irrefutable."
ABC News worked with an expert who created a computer-generated reconstruction of the shooting based on maps, blueprints, physical measurements, more than 500 photographs, films and autopsy reports, ABC said.
It enables a person to view the scene from any number of perspectives, including what Oswald saw from the sixth floor of the former Texas schoolbook depository, Yellin said.
"When you do that, it's chillingly clear what happened," Yellin said.
Nothing like re-opening another of history's wounds, eh?