Who killed JFK?

Who killed JFK?

This is probably the biggest mystery in American history that will never be resolved to everyone's satisfaction. On Nov. 22, 1963, President John F. Kennedy was shot in Dallas by Lee Harvey Oswald (although some speculate that he wasn't the only one shooting). On Nov. 24, 1963, before Oswald could stand trial, Oswald was fatally shot by nightclub owner Jack Ruby. Ruby died of lung cancer on Jan. 3, 1967. 

The most widely accepted explanation is that Oswald killed JFK on his own and Ruby killed Oswald, on his own volition. Ruby's stated motivation was to spare Jacqueline Kennedy "the discomfiture of [Oswald] coming back to trial." However there are still a significant number of professional historians, along with many amateurs, who do not agree with this explanation and since JFK's death, numerous alternative explanations have been brought forward by historians and amateurs. Given that significant new evidence is unlikely to appear, a firm consensus will probably never be reached.