The long-awaited release of the final John F. Kennedy assassination files raised as many questions as answers, with no stoppage to conspiracy theories and no definitive answer to the biggest question of all — did Lee Harvey Oswald really kill JFK on Nov. 22, 1963?

For more than a half century, the theorists waited for an answer. This was perhaps their final, best chance to get the information they’ve been seeking.

President Donald J. Trump released 3,810 files on Nov. 26 related to the assassination of President Kennedy, prompted by the Kennedy Assassination Records Collection Act of 1992. But not a single file was able to shed light on some of the most elusive answers to what some consider the biggest unsolved crime of the 20th century.

According to a poll conducted by FiveThirtyEight and SurveyMonkey from Oct. 17-20, out of 5,130 adults who responded about 33 percent believe that one man single-handedly killed JFK, while 61 percent believe that there were others involved in the murder.

Twenty years ago, however, far more people believed in a conspiracy, with many feeling that Oswald, in fact, may have been set up as a patsy. Why the shift over 20 years?

Possibility 1: The inability of conspiracy theorists to provide definitive proof. The conspiracists insist that they are bent on uncovering the truth, while many in this “post truth” age suggest that such truth doesn’t really exist, can never be known, and doesn’t really matter anyway.

Possibility 2: Computerized evidence that makes a strong case for Oswald as a lone assassin. An analysis conducted by researchers from the University of Rhode Island used neutron activation and ballistics evidence. The researchers argued that President Kennedy and Texas Gov. John Connally were hit by two bullets and only two bullets, both fired from Oswald’s rifle.

Possibility 3: A matter of demographic changes. Out of the 5,130 adults, 42 percent of all college graduates believe that one man killed JFK compared to 29 percent of people without a college degree.

The documents probably will never end the debate or speculation — and a few may add to the questions. In a 1975 deposition, for example, Richard Helms, the former CIA director, was asked: “Is there any information involved with the assassination of President Kennedy which in any way shows that Lee Harvey Oswald was in some way a CIA agent or an agen–”

But the document ends there, and Mr. Helms’ answer is missing.

“As long as the government is withholding documents like these, it’s going to fuel suspicion that there is a smoking gun out there about the Kennedy assassination,” said Patrick Maney, a presidential historian at Boston College.

Some questions — and some criminal cases — are destined to remain mysteries, and this might be one of them.