Woody Harrelson's late father Charles Harrelson was a Texas hit-man who had famously claimed to have killed President Kennedy (he was sentenced to life in prison for murdering a Texas judge), but later admitted that he made-up the story.
Democrat President Lyndon Johnson continued the FBI's wiretapping of Martin Luther King Jr'., that had been previously authorized by the Kennedy Administration of President John F. Kennedy. As a result of listening to the FBI's tapes, remarks on King's extra-marital activities were made by several prominent officials, including Johnson, who once said that King was a "hypocritical preacher".
This is Gary Grubbs second filminvolving the aftermath of the Kennedy Assassination. The first being JFK (1991). In that film he was a member of Jim Garrison's legal team investigating the assassination.