Kenneth O'Donnell was born in Worcester, Massachusetts, on 4th March, 1924. During theSecond World War O'Donnell served in the US Airforce (1942-1945). After the war O'Donnell studied at Harvard University where he met Robert Kennedy. He also attended Boston College Law School.
O'Donnell worked in public relations before being appointed as Assistant Counsel, Select Committee to Investigate Improper Activities in Labor-Management Relations in the Senate (1957-59).
In 1960 O'Donnell was the organizer and director of John F. Kennedy's presidential campaign schedule. The following year he became Kennedy's special assistant. O'Donnell was an early critic of the Vietnam War and advised Kennedy to bring an end to America's involvement in the conflict.
In November, 1963, he was involved in the organization of the presidential trip to Dallas, Texas. This involved discussions with Winston G. Lawson (secret service agent in charge of the trip), Roy Kellerman and Jesse Curry(chief of police in Dallas).
On the 22nd November, 1963, O'Donnell travelled in the Secret Service car immediately behind the presidential car. O'Donnell later wrote, "After the second shot, Dave Powers said to me, 'Kenny, I think the president's been shot!' I made a quick sign of the cross. While we both stared at the president, a third shot took the side of his head off. We saw pieces of bone and brain tissue and bits of reddish hair flying through the air. The impact lifted him and shook him limply as if he were a rag doll, and then he dropped out of our sight, sprawled across the back seat of the car."
Several witnesses said that William Greer stopped the car after the first shot was fired. This included Jean Hill, who was the closest witness to the car when Kennedy was hot: According to Hill "the motorcade came to almost a halt at the time the shots rang out". James Chaney (one of the four Presidential motorcyclists) - stated that the limousine "after the shooting, from the time the first shot rang out, the car stopped completely, pulled to the left and stopped." Mary Woodward, a journalist with the Dallas Morning News wrote: "Instead of speeding up the car, the car came to a halt... after the first shot".
O'Donnell later wrote: "If the Secret Service men in the front had reacted quicker to the first two shots at the President's car, if the driver had stepped on the gas before instead of after the fatal third shot was fired, would President Kennedy be alive today? He added "Greer had been remorseful all day, feeling that he could have saved President Kennedy's life by swerving the car or speeding suddenly after the first shots."
O'Donnell told the Warren Commission that the shooting had come from the rear. He later told his friend, Tip O'Neill, that he had been under pressure from the Federal Bureau of Investigation to say this. In fact, he believed that the gunfire had come from in front of the motorcade. O'Donnell commented: "I told the FBI what I had heard, but they said it couldn't have happened that way and that I must have been imagining things. So I testified the way they wanted me to. I just didn't want to stir up any more pain and trouble for the family." This story was backed up by David F. Powers, who was sitting next to O'Donnell in the motorcade.
In 1965 O'Donnell established his own management consulting company. In that year he was also an unsuccessful candidate for the Democratic nomination for Governor of Massachusetts. In 1968 O'Donnell was the campaign manager of the Robert Kennedy presidential campaign. After the assassination of Kennedy he helped the campaign of Hubert Humphrey.
Kenneth O'Donnell and David F. Powers began work on a book on their time with John F. Kennedy. The bookJohnny, We Hardly Knew Ye: Memories of John Fitzgerald Kennedy was published in 1976.
Kenneth O'Donnell died on 9th September, 1977, of the effects of alcoholism. His daughter, Helen O'Donnell, published the book, A Common Good: The Friendship of Robert F. Kennedy and Kenneth P. O'Donnell in 1998.