It is great that this movie has been made. There is no statute of limitations on negligent homicide. As an Irish guy from Boston, the Kennedys were an embarrassment. Worse were the hundreds of thousands that voted for Ted despite Chappaquicick. I guess that being Irish, Catholic, and part of the family that had experienced tragedy outweighed what Ted did. Howie Carr (conservative Boston talk show host for past 25 years) wrote a book last year detailing the incredibly dysfunctional history of the Kennedys - Kennedy Babylon. https://www.amazon.com/Kennedy-Babylon-Century-Scandal-Depravity/dp/0986193305/ref=sr_1_1?ie=UTF8&qid=1522336177&sr=8-1&keywords=kennedy+babylon
Statute of limitations issue is irrelevant when the perp is dead.