When you're rich enough to buy-off all the official investigators into a suspicious death, it makes life very convenient - for the conspiracy theorists, that is. It means they can twist the facts and fancies to fit any allegation they want.
The known facts are that William Randolph Hearst had agreed to collaborate with the acclaimed Hollywood director Thomas Ince on a series of film-spectaculars, starring Hearst's mistress Marion Davies, and offered to celebrate Ince's birthday with a grand party on-board his yacht (which would be outside the three-mile limit, and not subject to prohibition). Despite doctor's orders not to indulge in rich food and drink, Ince accepted the invitation.
The favourite version of what followed is that Hearst had included Charlie Chaplin on the guest-list in order to catch him getting too friendly with Davies, who was known to be a fan. In poor light, Hearst saw Davies embracing a male figure that he thought was Chaplin, and shot him dead with the silver revolver he always carried, using his influence to have the corpse taken off the boat and hurriedly cremated before there could be an autopsy. But it wasn't Chaplin after all, it was Ince. Embarrassingly, there had also been a witness in the shape of gossip-columnist Louella Parsons, who was promptly bought-off too, with a huge syndication deal that transformed her career.
It seems to have been a spot of blood on Ince's shirtfront that sparked-off the murder theory. Was it a bullet-hole or just a case of a known heavy smoker coughing up residue from a damaged lung? Two grand-daughters (one from each side) firmly deny any murder. Also it seems that Parsons' big contract had actually been awarded the year before.
But if there was no foul play, why did Chaplin forcefully deny that he was ever on-board, when it has been well confirmed that he was? And Parsons the same, when she probably was?
At a range of almost a century, it seems unlikely that we shall ever resolve the puzzle. But it remains a big part of California mythology, presented here with the familiar whiplash delivery of A.J. Benza - accompanied towards the end by what sounds like a slow, orchestral rendering of Irving Berlin's 'Blue Skies', often seen as a code for those innocent Twenties that may not have been quite as innocent as they looked.