It has been nearly six decades since President John F. Kennedy was fatally shot while traveling in a convertible limousine along Dallas' Dealey Plaza.

However, last week saw renewed interest in the president's assassination after a retired Secret Service agent shared memories of the event that appear to conflict with official accounts. 

Agent says he found bullet lodged in car seat

According to the New York Post, 88-year-old Paul Landis had been assigned to protect First Lady Jackie Kennedy during the president's 1963 Dallas visit.

Landis told The New York Times that he was just feet away from the president when a gunshot went off. The former agent said this shot was quickly followed by two additional gunshots.

He recalled seeing President Kennedy collapse in the convertible as well as having to duck in order to avoid being struck by pieces of Kennedy's brain.

Landis then described picking up a bullet which he found lodged in the back seat of the car which had been facing Kennedy. He then claimed to have placed the bullet on the president's stretcher.

Landis' account differs from official narrative

The Post pointed out that this account is at variance with the version of events popularized by the Warren Commission.

Headed by then-Supreme Court Justice Earl Warren, it was tasked by President Lyndon Johnson with investigating Kennedy's assassination.

The commission's report states that the bullet was discovered on the stretcher of Texas Democratic Gov. John Connally after it fell from a wound in his thigh.

Commissioners concluded that of the three shots that were fired, the first missed the car completely, the third struck Kennedy in his head, while the second passed through Kennedy’s throat before hitting Connally's back, chest, wrist and thigh. Critics have dubbed this account the "magic bullet theory."

Agent's book is scheduled to come out next month

However, Landis insists that the bullet he placed on the president's stretcher must have at some point been transferred to the one occupied by Connally.

"There was nobody there to secure the scene, and that was a big, big bother to me. All the agents that were there were focused on the president," Landis was quoted as saying.

Landis, who was never interviewed by the Warren Commission, said that he is now beginning to doubt whether gunman Lee Harvey Oswald acted alone as per the commission's findings.

The agent wrote a book that is scheduled to be released next month called, "The Final Witness: A Kennedy Secret Service Agent Breaks His Silence After Sixty Years."