I was referring to Boardwalk Empire, the TV series.
https://www.rottentomatoes.com/tv/boardwalk-empire
The TV series actually mixes fictional characters with real characters. There is a character based on Al Capone, but then there are characters that are entirely fictional.
A character who plays JFK's father makes an appearance in the show as it is alleged (and denied by many reports) that he was involved in Bootlegging.
Also, my comment is based on various mobsters claiming JFK was killed by the mafia.
But it's an unproven conspiracy.