A Secret Service agent who tried to shield former President John F. Kennedy from an assassin’s gunfire in 1963 died on Monday. Clint Hill, 93, died at his California home from unknown causes. He had been serving on presidential security detail for just three years when he made the move that defined his career.

The John F. Kennedy Presidential Library and Museum is paying tribute to Clint Hill, the secret service agent who famously jumped onto President Kennedy’s motorcade after the president was shot and killed in Dallas in 1963.

Clint Hill, the Secret Service agent who leaped onto the back of President John F. Kennedy's limousine after the president was shot, then was forced to retire early because he remained haunted by memories of the assassination, died Friday. He was 93.