One of the most intriguing mysteries about the assassination of John F. Kennedy, that darkest of American labyrinths, is why his brother Robert F. Kennedy apparently did nothing to investigate the crime. Bobby Kennedy was, after all, not just the attorney general of the United States at the time of the assassination -- he was his brother's devoted partner, the man who took on the administration's most grueling assignments, from civil rights to organized crime to Cuba, the hottest Cold War flashpoint of its day. But after the burst of gunfire in downtown Dallas on Nov. 22, 1963, ended this unique partnership, Bobby Kennedy seemed lost in a fog of grief, refusing to discuss the assassination with the Warren Commission, and telling friends he had no heart for an aggressive investigation. "What difference does it make?" he would say. "It won't bring him back."

But Bobby Kennedy was a complex man, and his years in Washington had taught him to keep his own counsel and proceed in a subterranean fashion. What he said in public about Dallas was not the full story. Privately, RFK -- who had made his name in the 1950s as a relentless investigator of the underside of American power -- was consumed by the need to know the real story about his brother's assassination. This fire seized him on the afternoon of Nov. 22, as soon as FBI chief J. Edgar Hoover, a bitter political enemy, phoned to say -- almost with pleasure, thought Bobby -- that the president had been shot. And the question of who killed his brother continued to haunt Kennedy until the day he too was gunned down, on June 5, 1968.

Because of his proclivity for operating in secret, RFK did not leave behind a documentary record of his inquiries into his brother's assassination. But it is possible to retrace his investigative trail, beginning with the afternoon of Nov. 22, when he frantically worked the phones at Hickory Hill -- his Civil War-era mansion in McLean, Va. -- and summoned aides and government officials to his home. Lit up with the clarity of shock, the electricity of adrenaline, Bobby Kennedy constructed the outlines of the crime that day -- a crime, he immediately concluded, that went far beyond Lee Harvey Oswald, the 24-year-old ex-Marine arrested shortly after the assassination. Robert Kennedy was America's first assassination conspiracy theorist.

CIA sources began disseminating their own conspiratorial view of Kennedy's murder within hours of the crime, spotlighting Oswald's defection to the Soviet Union and his public support for Fidel Castro. In New Orleans, an anti-Castro news organization released a tape of Oswald defending the bearded dictator. In Miami, the Cuban Student Directorate -- an exile group funded secretly by a CIA program code-named AMSPELL -- told reporters about Oswald's connections to the pro-Castro Fair Play for Cuba Committee. But Robert Kennedy never believed the assassination was a communist plot. Instead, he looked in the opposite direction, focusing his suspicions on the CIA's secretive anti-Castro operations, a murky underworld he had navigated as his brother's point man on Cuba. Ironically, RFK's suspicions were shared by Castro himself, whom he had sought to overthrow throughout the Kennedy presidency.

The attorney general was supposed to be in charge of the clandestine war on Castro -- another daunting assignment JFK gave him, after the spy agency's disastrous performance at the Bay of Pigs in April 1961. But as he tried to establish control over CIA operations and to herd the rambunctious Cuban exile groups into a unified progressive front, Bobby learned what a swamp of intrigue the anti-Castro world was. Working out of a sprawling Miami station code-named JM/WAVE that was second in size only to the CIA's Langley, Va., headquarters, the agency had recruited an unruly army of Cuban militants to launch raids on the island and even contracted Mafia henchmen to kill Castro -- including mob bosses Johnny Rosselli, Santo Trafficante and Sam Giancana, whom Kennedy, as chief counsel for the Senate Rackets Committee in the late 1950s, had targeted. It was an overheated ecosystem that was united not just by its fevered opposition to the Castro regime, but by its hatred for the Kennedys, who were regarded as traitors for failing to use the full military might of the United States against the communist outpost in the Caribbean.

This Miami netherworld of spies, gangsters and Cuban militants is where Robert Kennedy immediately cast his suspicions on Nov. 22. In the years since RFK's own assassination, an impressive body of evidence has accumulated that suggests why Kennedy felt compelled to look in that direction. The evidence -- congressional testimony, declassified government documents, even veiled confessions -- continues to emerge at this late date, although largely unnoticed. The most recent revelation came from legendary spy E. Howard Hunt before his death in January. Hunt offered what might be the last will and testament on the JFK assassination by someone with direct knowledge about the crime. In his recent posthumously published memoir, "American Spy," Hunt speculates that the CIA might have been involved in Kennedy's murder. And in handwritten notes and an audiotape he left behind, the spy went further, revealing that he was invited to a 1963 meeting at a CIA safe house in Miami where an assassination plot was discussed.

Bobby Kennedy knew that he and his brother had made more than their share of political enemies. But none were more virulent than the men who worked on the Bay of Pigs operation and believed the president had stabbed them in the back, refusing to rescue their doomed operation by sending in the U.S. Air Force and Marines. Later, when President Kennedy ended the Cuban missile crisis in October 1962 without invading Cuba, these men saw not statesmanship but another failure of nerve. In Cuban Miami, they spoke of la seconda derrota, the second defeat. These anti-Kennedy sentiments, at times voiced heatedly to Bobby's face, resonated among the CIA's partners in the secret war on Castro -- the Mafia bosses who longed to reclaim their lucrative gambling and prostitution franchises in Havana that had been shut down by the revolution, and who were deeply aggrieved by the Kennedy Justice Department's all-out war on organized crime. But Bobby, the hard-liner who covered his brother's right flank on the Cuba issue, thought that he had turned himself into the main lightning rod for all this anti-Kennedy static.

"I thought they would get me, instead of the president," he told his Justice Department press aide, Edwin Guthman, as they walked back and forth on the backyard lawn at Hickory Hill on the afternoon of Nov. 22. Guthman and others around Bobby that day thought "they" might be coming for the younger Kennedy next. So apparently did Bobby. Normally opposed to tight security measures -- "Kennedys don't need bodyguards," he had said with typical brashness -- he allowed his aides to summon federal marshals, who quickly surrounded his estate.

Meanwhile, as Lyndon Johnson -- a man with whom he had a storied antagonistic relationship -- flew east from Dallas to assume the powers of the presidency, Bobby Kennedy used his fleeting authority to ferret out the truth. After hearing his brother had died at Parkland Memorial Hospital in Dallas, Kennedy phoned CIA headquarters, just down the road in Langley, where he often began his day, stopping there to work on Cuba-related business. Bobby's phone call to Langley on the afternoon of Nov. 22 was a stunning outburst. Getting a ranking official on the phone -- whose identity is still unknown -- Kennedy confronted him in a voice vibrating with fury and pain. "Did your outfit have anything to do with this horror?" Kennedy erupted.

Later that day, RFK summoned the CIA director himself, John McCone, to ask him the same question. McCone, who had replaced the legendary Allen Dulles after the old spymaster had walked the plank for the Bay of Pigs, swore that his agency was not involved. But Bobby Kennedy knew that McCone, a wealthy Republican businessman from California with no intelligence background, did not have a firm grasp on all aspects of the agency's work. Real control over the clandestine service revolved around the No. 2 man, Richard Helms, the shrewd bureaucrat whose intelligence career went back to the agency's OSS origins in World War II. "It was clear that McCone was out of the loop -- Dick Helms was running the agency," recently commented RFK aide John Seigenthaler -- another crusading newspaper reporter, like Guthman, whom Bobby had recruited for his Justice Department team. "Anything McCone found out was by accident."

Kennedy had another revealing phone conversation on the afternoon of Nov. 22. Speaking with Enrique "Harry" Ruiz-Williams, a Bay of Pigs veteran who was his most trusted ally among exiled political leaders, Bobby shocked his friend by telling him point-blank, "One of your guys did it." Who did Kennedy mean? By then Oswald had been arrested in Dallas. The CIA and its anti-Castro client groups were already trying to connect the alleged assassin to the Havana regime. But as Kennedy's blunt remark to Williams makes clear, the attorney general wasn't buying it. Recent evidence suggests that Bobby Kennedy had heard the name Lee Harvey Oswald long before it exploded in news bulletins around the world, and he connected it with the government's underground war on Castro. With Oswald's arrest in Dallas, Kennedy apparently realized that the government's clandestine campaign against Castro had boomeranged at his brother.

That evening, Kennedy zeroed in on the Mafia. He phoned Julius Draznin in Chicago, an expert on union corruption for the National Labor Relations Board, asking him to look into a possible mob angle on Dallas. More important, the attorney general activated Walter Sheridan, his ace Justice Department investigator, locating him in Nashville, where Sheridan was awaiting the trial of their longtime nemesis, Teamster leader Jimmy Hoffa.

If Kennedy had any doubts about a Mafia involvement in his brother's murder, they were immediately dispelled when, two days after JFK was shot down, burly nightclub owner Jack Ruby shouldered his way through press onlookers in the basement of the Dallas police station and fired his fatal bullet into Lee Harvey Oswald. Sheridan quickly turned up evidence that Ruby had been paid off in Chicago by a close associate of Hoffa. Sheridan reported that Ruby had "picked up a bundle of money from Allen M. Dorfman," Hoffa's chief advisor on Teamster pension fund loans and the stepson of Paul Dorfman, the labor boss' main link to the Chicago mob. A few days later, Draznin, Kennedy's man in Chicago, provided further evidence about Ruby's background as a mob enforcer, submitting a detailed report on Ruby's labor racketeering activities and his penchant for armed violence. Jack Ruby's phone records further clinched it for Kennedy. The list of men whom Ruby phoned around the time of the assassination, RFK later told aide Frank Mankiewicz, was "almost a duplicate of the people I called to testify before the Rackets Committee."

As family members and close friends gathered in the White House on the weekend after the assassination for the president's funeral, a raucous mood of Irish mourning gripped the executive mansion. But Bobby didn't participate in the family's doleful antics. Coiled and sleepless throughout the weekend, he brooded alone about his brother's murder. According to an account by Peter Lawford, the actor and Kennedy in-law who was there that weekend, Bobby told family members that JFK had been killed by a powerful plot that grew out of one of the government's secret anti-Castro operations. There was nothing they could do at that point, Bobby added, since they were facing a formidable enemy and they no longer controlled the government. Justice would have to wait until the Kennedys could regain the White House -- this would become RFK's mantra in the years after Dallas, whenever associates urged him to speak out about the mysterious crime.

A week after the assassination, Bobby and his brother's widow, Jacqueline Kennedy -- who shared his suspicions about Dallas -- sent a startling secret message to Moscow through a trusted family emissary named William Walton. The discreet and loyal Walton "was exactly the person that you would pick for a mission like this," his friend Gore Vidal later observed. Walton, a Time magazine war correspondent who had reinvented himself as a gay Georgetown bohemian, had grown close to both JFK and Jackie in their carefree days before they moved into the White House. Later, the first couple gave him an unpaid role in the administration, appointing him chairman of the Fine Arts Commission, but it was mainly an excuse to make him a frequent White House guest and confidant.

After JFK's assassination, the president's brother and widow asked Walton to go ahead as planned with a cultural exchange trip to Russia, where he was to meet with artists and government ministers, and convey an urgent message to the Kremlin. Soon after arriving in frigid Moscow, fighting a cold and dabbing at his nose with a red handkerchief, Walton met at the ornate Sovietskaya restaurant with Georgi Bolshakov -- an ebullient, roly-poly Soviet agent with whom Bobby had established a back-channel relationship in Washington. Walton stunned the Russian by telling him that the Kennedys believed Oswald was part of a conspiracy. They didn't think either Moscow or Havana was behind the plot, Walton assured Bolshakov -- it was a large domestic conspiracy. The president's brother was determined to enter the political arena and eventually make a run for the White House. If RFK succeeded, Walton confided, he would resume his brother's quest for détente with the Soviets.

Robert Kennedy's remarkable secret communication to Moscow shows how emotionally wracked he must have been in the days following his brother's assassination. The calamity transformed him instantly from a cocky, abrasive insider -- the second most powerful man in Washington -- to a grief-stricken, deeply wary outsider who put more trust in the Russian government than he did in his own. The Walton mission has been all but lost to history. But it is one more revealing tale that sheds light on Bobby Kennedy's subterranean life between his brother's assassination and his own violent demise less than five years later.

Over the years, Kennedy would offer bland and routine endorsements of the Warren Report and its lone gunman theory. But privately he derided the report as nothing more than a public relations exercise designed to reassure the public. And behind the scenes, he continued to work assiduously to figure out his brother's murder, in preparation for reopening the case if he ever won the power to do so.

Bobby held onto medical evidence from his brother's autopsy, including JFK's brain and tissue samples, which might have proved important in a future investigation. He also considered taking possession of the gore-spattered, bullet-riddled presidential limousine that had carried his brother in Dallas, before the black Lincoln could be scrubbed clean of evidence and repaired. He enlisted his top investigator, Walt Sheridan, in his secret quest -- the former FBI agent and fellow Irish Catholic whom Bobby called his "avenging angel." Even after leaving the Justice Department in 1964, when he was elected to the Senate from New York, Kennedy and Sheridan would slip back into the building now and then to pore over files on the case. And soon after his election, Kennedy traveled to Mexico City, where he gathered information on Oswald's mysterious trip there in September 1963.

In 1967, Sheridan went to New Orleans to check into the Jim Garrison investigation, to see whether the flamboyant prosecutor really had cracked the JFK case. (Sheridan was working as an NBC news producer at the time, but he reported back to RFK, telling him that Garrison was a fraud.) And Kennedy asked his press secretary, Frank Mankiewicz, to begin gathering information about the assassination for the day when they could reopen the investigation. (Mankiewicz later told Bobby that his research led him to conclude it was probably a plot involving the Mafia, Cuban exiles and rogue CIA agents.) Kennedy himself found it painful to discuss conspiracy theories with the ardent researchers who sought him out. But he met in his Senate office with at least one -- a feisty small-town Texas newspaper publisher named Penn Jones Jr., who believed JFK was the victim of a CIA-Pentagon plot. Bobby heard him out and then had his driver take Jones to Arlington Cemetery, where the newspaperman wanted to pay his respects at his brother's grave.

At times, this drive to know the truth would sputter, as Robert Kennedy wrestled with debilitating grief and a haunting guilt that he -- his brother's constant watchman -- should have protected him. And, ever cautious, Bobby continued to deflect the subject whenever he was confronted with it by the press. But as time went by, it became increasingly difficult for Kennedy to avoid wrestling with the specter of his brother's death in public.

In late March 1968, during his doomed and heroic run for the presidency, Kennedy was addressing a tumultuous outdoor campus rally in Northridge, Calif., when some boisterous students shouted out the question he always dreaded. "We want to know who killed President Kennedy!" yelled one girl, while others took up the cry: "Open the archives!"

Kennedy's response that day was a tightrope walk. He knew that if he fully revealed his thinking about the assassination, the ensuing media uproar would have dominated his campaign, instead of burning issues like ending the Vietnam War and healing the country's racial divisions. For a man like Robert Kennedy, you did not talk about something as dark as the president's assassination in public -- you explored the crime your own way.

But Kennedy respected college students and their passions -- and he was in the habit of addressing campus audiences with surprising honesty. He did not want to simply deflect the question that day with his standard line. So, while dutifully endorsing the Warren Report as usual, he went further. "You wanted to ask me something about the archives," he responded. "I'm sure, as I've said before, the archives will be open." The crowd cheered and applauded. "Can I just say," continued Kennedy, "and I have answered this question before, but there is no one who would be more interested in all of these matters as to who was responsible for uhb

Robert Kennedy did not live long enough to solve his brother's assassination. But nearly 40 years after his own murder, a growing body of evidence suggests that Kennedy was on the right trail before he too was cut down. Despite his verbal contortions in public, Bobby Kennedy always knew that the truth about Dallas mattered. It still does.

http://www.salon.com/books/feature/2007/05/02/brothers/