The video speaks for itself.
Against all logic - and standard security protocol - the two Secret Service bodyguards closest to Kennedy were told to stand down. Minutes later Kennedy was shot.
This footage was suppressed for many years after the assassination.
The "conspiracy theorists" who believe Kennedy was murdered by a lone nut who was in turn murdered by another lone nut have never addressed this footage.
As mainstream media appears to have a number of videos and other reports on the Kennedy assassination ready for popular consumption, you can be sure that none of it will seriously question the official version of what happened.