The effect of his editing was to suggest that a single bullet struck the assassinated president in the neck and severely wounded Texas Governor John Connally - a crucial element in its controversial finding that Lee Harvey Oswald was the sole gunman.
This latest revelation will fuel the debate about the Kennedy assassination and add weight to conspiracy theories which maintain that more than one gunman was responsible.
The president was shot on 22 November 1963, in Dallas, Texas. Oswald was arrested that day but was shot and killed two days later as he was being transferred from the city jail to the county jail.
Ford's changes tend to support the single-bullet theory by making a specific point that the bullet entered Kennedy's body "at the back of his neck" rather than in his uppermost back, as the commission staff originally wrote. Ford said last night that it was a small change, one intended to clarify the report and not to alter history.
Ford was a Republican leader in Congress at the time who became president when Richard Nixon resigned in 1974. He is the sole surviving member of the commission headed by Chief Justice Earl Warren.
"My changes had nothing to do with a conspiracy theory," he said. "My changes were only an attempt to be more precise."
However, his editing was seized upon by members of the conspiracy community, which rejects the commission's conclusion that Oswald acted alone.
"This is the most significant lie in the whole report," said Robert Morningstar, who has studied the assassination since it happened and has written a book about it.
The effect of Ford's editing, he said, was to suggest that a bullet struck Kennedy in the neck, "raising the wound two or three inches. Without that alteration, they could never have hoodwinked the public as to the true number of assassins."
The Warren Commission concluded in 1964 that a single bullet - fired by a "discontented" Oswald - passed through Kennedy's body and wounded his motorcade passenger, Connally, and that a second, fatal bullet fired from the same place, tore through Kennedy's head.
Ford's notes were contained in 40,000 pages of records kept by J. Lee Rankin, chief counsel of the commission. They were made public yesterday by the Assassination Record Review Board, an agency created by Congress to amass all relevant evidence in the case.
Staff of the commission had written: "A bullet had entered his back at a point slightly above the shoulder and to the right of the spine." But Ford had suggested changing it to read: "A bullet had entered the back of his neck at a point slightly to the right of the spine", which is what appeared in the final report.
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