Read The Marilyn Tapes by E. J. Gorman. I don't know much about this author. His biography simply states "lives in Cedar Rapids, Iowa."
I do know that this book is likely to reawaken an old obsession of mine. This book did such a fantastic job of hiding the line that separates fact from fiction that I'm feeling the urge to do some research. See if I can discover where the line lies.
The major players definitely existed. Marilyn, JFK, Bobby, Hoover. What is less clear (at least to the general public) is the relationships between them. Did Marilyn sleep with both Kennedys? Did Hoover really seek to control the brothers? What secrets were hidden in Marilyn's past?
The murders at the heart of this novel were fiction (at least I think so). But, every element of this story COULD have happened. I love fiction that manages to convince me that it's a true story!