unexplained-events:

On the day that John F. Kennedy was assassinated in Dealey Plaza, dozens of people captured photographic evidence of the murder.In order to determine exactly what happened that day, government officials have examined and scrutinized every angle of the videos. In some cases, mysterious people of interest have been identified. One of the most famous examples is the Babushka Lady(more on this later), who was witnessed filming near the assassination, but never identified by the police.

Another mysterious figure that was seen during the JFK assassination is the umbrella man. The umbrella man can be seen in several videotapes and photographs of the assassination, including the Zapruder film. He is the only person in Dealey Plaza with an umbrella, which has been deemed unusual because it was a clear day. In the videos, the umbrella man can be seen opening his umbrella and lifting it high above his head as JFK’s limousine approached. He then spun the umbrella clockwise as the limo slowed down and JFK was shot.

Theories suggest that he used the umbrella to signal the shooters.
Another theory suggests that he used the umbrella to tell the driver to slow down.