Was JD Tippit on the grassy knoll?

No, JD Tippit was not on the grassy knoll. He was a Dallas police officer who was shot and killed by Lee Harvey Oswald approximately 45 minutes after the assassination of President John F. Kennedy. The grassy knoll is often associated with conspiracy theories regarding the assassination, but there is no evidence linking Tippit to that location during the events of November 22, 1963.