According to this story from Exopolitics.org, that may very well be the case!  The piece goes on to say that Marilyn Monroe had direct knowledge that JFK had seen a crashed UFO.  When combined with her mysterious death, the mind races with the implications.  Regardless of who or why, I have always felt that the Marilyn Monroe suicide was a little too pat given the circles in which she, um, traveled.  You be the judge and check out this compelling account.

Link: Exopolitics.org