Was Bobby Kennedy in on the plot to kill JFK? Before you think, good God, another nut, another preposterous theory, stay with me for this thought experiment. Consider these arguments. Bobby Kennedy had the means, motive, and opportunity to kill his brother. He had all the right connections with the Cuban exiles, trained in murder, ruthless and motivated to see the president dead. Fratricide was his surest path to the throne, once he put Lyndon Johnson out of the way. Jack trusted Bobby more than he trusted anyone else, and would never have guarded himself from his best friend.

The further you pursue this possibility, the more it makes sense. Yet no one thought of this possibility. When police investigate a murder, the first people they question are those the victim knows best. Instead of following standard procedure, the FBI fixed on Lee Oswald immediately after Kennedy died. It did not investigate the president’s brother at all. If the FBI had at least talked to the attorney general, they might have learned some interesting things.

Bobby Kennedy as the prime mover behind his brother’s death resolves multiple mysteries connected with the event. Bobby was his brother’s liaison with the CIA. Lee Oswald worked for the agency, and for the FBI, long before his employers set him up to take the fall on November 22, 1963. Second, the attorney general prosecuted Carlos Marcello, Mafia boss in New Orleans: Bobby Kennedy had him deported, in fact. Marcello had close ties with Jack Ruby, Oswald’s killer, and plenty of reason to hate the Kennedys. Lastly, Bobby Kennedy failed to warn his brother about trouble in New Orleans, or threats that awaited him in Dallas. “I thought they would come after us,” he said of his enemies when he heard the news from Texas, “but I thought it would be me.” Was that a clever instance of misdirection, to throw the FBI off the scent?

Most telling of all, Bobby Kennedy, despite his power as attorney general, never acted to find his brother’s killer, or to discredit those who ginned up a false brief against Oswald. He permitted Lyndon Johnson and J. Edgar Hoover to concoct an incredible story about intelligence asset Oswald firing on the president for no reason: with no motive at all that anyone could see. Bobby’s friends were perplexed, because he knew it could not be true. He let the new president, the director of the FBI, and the chief justice of the Supreme Court pass off this nonsense to the public with a formal report. Bobby was the chief law enforcement officer in the country for most of the time the Warren Commission conducted its investigation. He could have done something to find the truth. Why didn’t he?

Let’s pause in this thought experiment for a moment. Do these arguments appear plausible? Perhaps. If nothing else, they show how quickly speculation about infamous, unsolved crimes can lead researchers into tricky terrain. No amount of straight-cut logic, by itself, can overcome these difficulties. Evidence-based analysis and sound logic both go a long, long way, but you can still make mistakes if you are not careful. That is one reason collaborative research produces reliable results: it prevents mistakes.

After I published the thought experiment above – without calling it out as a thought experiment and before I wrote any follow-up analysis – a friend wrote to say, “I think you are completely off base on this one. …Bobby did not pursue the real killers – LBJ and Allen Dulles and etc – because he needed the power of the presidency behind him to pull off the level of house cleaning required.” With that I thought, it’s time to write part two of this essay. Here’s some helpful analysis.

The first point concerns the opening question: “Was Bobby Kennedy in on the plot to kill JFK?” In on is not particularly useful for analysis or evaluation of evidence. It simply serves as a conversation starter if you want to play the who dunnit parlor game. It is entirely too open and imprecise. Was the Mossad or any other part of the Israeli government in on the plot to blow up the World Trade Center? Was the Mafia in on the plot to kill Kennedy? Was the CIA in on the plot to kill Bobby Kennedy? These questions may be alright if they are the first ones to come to mind, but they are weak tools for analysis or investigation. Researchers who want to draw useful conclusions recognize the indeterminacy of a phrase like that, then refine the question to eliminate that weakness. Weak questions yield weak results.

A second point of the thought experiment is to demonstrate, in a crime like Kennedy’s murder, how you can make the implausible sound possible and even reasonable without doing much violence to well accepted knowledge. Tailor your sentences correctly, and you can create verbal illusions. The illusions become especially effective if you convince yourself they are true. Arlen Specter’s magic bullet theory fits that description. Just as no one who has looked at the evidence believes the magic bullet theory, no one familiar with Bobby Kennedy thinks he had his brother murdered. Yet you can make the hypothesis appear reasonable enough. If that’s the case, what do we do to reject, or at least set aside, ideas like this one? Here are some thoughts related to that question.

Inadequacy of the means, motive, and opportunity test for ruling hypotheses in or out.

We know the means, motive, and opportunity test. A person who has the means, motive, and opportunity to commit the crime is a suspect. You often see this standard applied with the cui bono test, who benefits from the crime? As the Bobby Kennedy thought experiment suggests, both tests are of questionable value if not accompanied by other evidence. Yes, researchers can use these questions to rule suspects in or out, but the potential number of false positives is huge. That is, you include an enormous number of people in your suspect pool that could not possibly have committed the crime. Bobby Kennedy as a suspect in his brother’s murder is an example. He meets the standard criteria for a suspect, but any investigator interested in the truth would know Bobby Kennedy is not a suspect.

Lee Oswald is another false positive, for that matter, though careful researchers would argue that he did not have an adequate weapon, a clear reason, or a clear shot. He certainly did not have a clear shot from Kennedy’s right side, the origin of the fatal shot, because he was not located there. If we apply standard tests, one set of investigators might rule Oswald in and identify him as the sole shooter, as the Warren Commission did. Another set of investigators might use the same tests to rule him out. Results of the means, motive, and opportunity tests are not unambiguous.

In sum, the three-part test seems rigorous, but it performs poorly when you want to rule people out. So you pretend to be rigorous when you are not. You think that if you make each suspect meet each test, you can eliminate all but a narrowly defined group. Every time you take another look, though, the number of people who had the means, motive, and opportunity expands still more. Bobby Kennedy becomes a prime suspect with this test, as do a host of Mafia figures and other assassins at the CIA’s disposal. However you conduct your investigation, you cannot stop with the standard criteria.

Use of innuendo and non-sequiturs to suggest false possibilities.

The middle of the thought experiment teems with innuendo and non-sequiturs. If you think Bobby neglected his brother’s welfare, you have travelled a long way down the wrong road. Yet liars in high positions can make anything sound reasonable. The idea that Bobby Kennedy killed his brother is no more improbable or outlandish than the idea that Lee Oswald did. The only reason people think Oswald killed the president is that someone with a badge, and someone named Earl Warren told them so. If the chief justice of the Supreme Court had reported that Elmer Fudd had assassinated the president, do you suppose anyone would have laughed at him? The lies put out before the United States attacked Iraq in 2003 show outlandish falsehoods accepted as true because people with weighty reputations gave the lies credence.

Lyndon Johnson was perhaps the most practiced liar of his generation, yet people did not recognize it till the debacle in Vietnam. Most people he led accepted his version of events in Dealey Plaza, where he ducked down in his car well before the first shots hit the motorcade. He knew what was coming, and he did not even have the manliness to sit up during the execution. Then he used his prestige, his personality, and his power to make fictional statements about the execution seem real.

Reliance on reasoning from negatives: conclusions drawn from what did not happen.

The thought experiment asks why Bobby Kennedy, at the head of the Department of Justice, did not move to find his brother’s killer. Reasoning from negatives can actually be a powerful tool. For the 9/11 attacks, one asks why the United States air defense system did not scramble fighters to intercept the hijacked airliners. When you use this type of reasoning, however, researchers have to compare what did happen with what did not. Government agencies and officials are well known for incompetence, neglect, mixed motives, poor judgment, bad decisions under pressure: all kinds of mistakes people are subject to. These weaknesses can cause people not to do things you might expect them to do. No matter how you consider the 9/11 attacks, inaction in that instance was so systemic that failure to respond to the attacks is inexplicable unless you assume a stand down order was in place.

In Bobby Kennedy’s case, you needn’t allow for mistakes or stand down orders. He was incapacitated by grief over the loss of his brother during the period that Hoover and his FBI collaborated with the Warren Commission to compile the commission’s report. He was not an active attorney general during these months, nor was he in a position to be, given the rock-bottom state of his working relationships with Hoover and Johnson. After the Warren Commission’s report came out in September 1964, the attorney general recognized that he could not pursue his brother’s killers if he were not president. He had to know as well that if he was correct about who killed his brother, he would probably never become president.

Importance of context and background in assessing arguments.

During the 1960s, speculation about who actually killed the president ran rampant, if somewhat underground. Reasonable doubts, new possibilities, and sometimes dubious theories sprouted in soil well fertilized by the Warren report. In that environment, mainstream media and others could dismiss Jim Garrison’s case against Clay Shaw as one more misdirected, unwelcome theory. What’s that guy Garrison doing down in New Orleans? Yet subsequent research proved Jim Garrison correct. We know Jim Garrison was correct because we have better information now than we did then. We want the truth now more than we did then.

Every generation has new resources to understand the past. The investigators of the 1960s – early researchers like Harold Weisberg, Mark Lane, and Josiah Thompson – started the process that led to books by David Talbot, James Douglass, and others more than forty years later. The early researchers represented the truthers of their time: ridiculed, mocked, and dismissed. Later investigators vindicated their work. The best books – such as Me and Lee by Judyth Vary Baker and Mary’s Mosaic by Peter Janney – knit together a rich background of details and remembrance. These memories develop the individuals in the drama, reveal their true roles and relationships, and give credence to previously speculative ideas. Investigators have always hoped these stories would come out. Now they have.

From the beginning of my research, I thought that if we could only know more about personal relationships among the various characters on the set, we could figure out the mysteries behind this crime. By good fortune, books that contain just this kind of rich background have appeared during the last five to ten years. We have had to wait a long time. Now we can see that careful work by skeptics during the decade after the murder support narrative accounts published forty to fifty years after Kennedy died. These stories help us reach accurate judgments about which arguments ring true, and which do not.