Nemesis: Aristotle Onassis, Jackie O and the Love Triangle That Brought Down the Kennedys, by Peter Evans

Peter Evans makes the case that Aristotle Onassis knowingly funded the assassination of Bobby Kennedy to get even for Kennedy's successes in blocking some of Onassis's shadier business dealings and to clear the way for his marriage to Jackie.  I'd say the evidence is circumstantial and his confession to Helene Gaillet not entirely reliable.  I probably couldn't convict.  Besides the Kennedy assassination, there are lots of deaths and lots of questions are raised about those deaths.  And lots of loveless marriages and secret and public affairs.  Pretty darned readable.