A Cruel and Shocking Act: The Secret History of the Kennedy Assassination feels like it’s full of secrets, this slab of an investigation into arguably the most famous assassination in the history of the United States. We here at Kirkus have had to sign Serious Documents in order to get our hands on this secret history of the assassination of John F. Kennedy, almost 50 years to the day since our President was gunned down in Dealey Plaza. It’s almost a bit unnerving to page through a book which has the word “CONFIDENTIAL” stamped not just on the cover, but every single interior page: Welcome to the murky world of embargoed books.

The new investigation, named for a line in the final report of the Warren Commission, is by former New York Times reporter Philip Shenon, who performed a very similar post-mortem in his last book, The Commission: The Uncensored History of the 9/11 Investigation (2008). In his prologue, Shenon reveals that it was that book that prompted a prominent American lawyer who had worked on the Warren Commission’s inquiry to call the reporter. “You ought to tell our story,” said the attorney. “We’re not young, but a lot of us from the commission are still around, and this may be our last chance to explain what really happened.”

Now that Shenon’s investigation is hitting bookstore shelves, his conclusions can finally be revealed to the public. Delving into one of America’s greatest mysteries, Kirkus Reviews runs down 10 of the revelatory moments in A Cruel and Shocking Act.

The FBI rushed to judgment in order to discredit the work of the Warren Commission. By mid-December of 1963, the Bureau—famously headed by Kennedy family enemy J. Edgar Hoover—had leaked the results of its internal investigation in a messy, incomplete and confusing report that put the blame squarely on lone gunman Lee Harvey Oswald. Justice Earl Warren himself complained, “Gentlemen, to be very frank about it, I have read that report two or three times and I have not seen anything in there that has not been in the press.” Not to mention his succinct assessment, “This bullet business leaves me confused.”

A smart-ass reporter nearly broke the FBI. One of the story’s most interesting characters has always been Hugh Aynesworth, the Dallas reporter who happened to witness the assassination, Oswald’s arrest, and his shooting at the hands of Jack Ruby. Less reported is the fact that Aynesworth became one of the primary investigators of the assassination, breaking story after story. Queried by fellow journalist Alonzo "Lonnie" Hudkins of the Houston Post about Oswald’s connection to the FBI, Aynesworth joked, “You got his payroll number, don’t you?” and then rattled off a random series of numbers. On January 1^st, 1964, Aynesworth was startled to see that Hudkins had written a front page story for the Post titled “Owald Rumored as Informant for U.S.” The story, erroneous or not, prompted a firestorm of accusations between the Warren Commission, the FBI and the Secret Service.

Where is John F. Kennedy’s brain? The whereabouts of President Kennedy’s brain, removed during his autopsy by Commander James Hume, has been one of the oddest mysteries of the assassination, but Shenon thinks he has it figured out. Rear Admiral George Burkley, the President’s personal physician, transferred the organ to Kennedy’s former secretary, Evelyn Lincoln, and it was stored for a short period at the National Archives. The executors of Kennedy’s estate suspected that Robert Kennedy ultimately obtained the brain and disposed of it, lest it end up on public display in the Smithsonian.

Playing hide-and-seek with the spooks. There’s a troubling pattern of deception and subversion on the part of the FBI and CIA in Shenon’s account of the investigation. The day after the assassination, the FBI office in Dallas destroyed a disturbing hand-written note that Oswald delivered personally warning them to stop bothering his Russian-born wife, Marina. In another incident, a young investigator notes that 37 documents disappeared from the internal file the CIA maintained on Oswald prior to the assassination.

Partying with the Secret Service in Dallas. Shenon dug up another old story that was long since buried by the abundance of data on the assassination. Long before the Treasury was scandalized by prostitutes in Cartagena, its own Secret Service agents were boozing it up in Dallas until three in the morning, with at least one reported to be inebriated at the time of the shooting. Not a single agent was ever disciplined over the incident.

The Warren Commission took secret testimony from Fidel Castro. One of the book’s most fascinating turns takes legal icon William Coleman back to the summer of 1964, when he was sent on a secret mission to meet with Fidel Castro off the coast of Cuba. Coleman and the Cuban revolutionary were friends who met in the jazz clubs of Harlem, so when Castro used back door channels to contact the Warren Commission, Coleman traveled to Castro’s yacht off the coast of Cuba to meet with him. “I’m not saying he didn’t do it,” Coleman later said. “But I came back and I said that I hadn’t found out anything that would cause me to think there’s proof he did do it.”

Earl Warren was very uncomfortable taking testimony from Jacqueline Kennedy. Justice Warren put off interviewing the First Lady until as late as June 5, 1964, out of sheer discomfort with questioning her. The interview was conducted at Mrs. Kennedy’s colonial mansion, which had become her virtual prison in the wake of the assassination. Robert Kennedy sat in on the testimony, as Jacqueline Kennedy recounted the gruesome experience of seeing her husband killed right in front of her. Her famous pink Chanel suit remains in the National Archives, her husband’s blood still on it. She had no memory of trying to climb out of the car.

The grief and the fury of Robert Kennedy. Perhaps only Jacqueline Kennedy felt as much grief as Jack’s brother, Bobby. Robert Kennedy lost his brother and his best friend in that terrible moment in Dallas, and had to hear the news from no less than his sworn nemesis, J. Edgar Hoover. Kennedy recalled the coldness in Hoover’s voice when he called to say, “I have news for you. The president has been shot.” In the days after, Bobby had taken to wearing his dead brother’s clothes and making late-night visits to Arlington National Cemetery. But he could still raise hell, as he did when President Lyndon Johnson mused that the assassination was “divine retribution” for interfering in Vietnam. Afterwards, Kennedy characterized the comment as the  worst thing that Johnson ever said.

Key figures are still alive. Much of the evidence suppressed or destroyed involved Oswald’s involvement with a woman named Silvia Duran, who was a staunch Communist and rumored to have had an affair with Oswald. Astoundingly, the author managed to track down Duran in Mexico City after five decades, where she continues to deny the rumors and reports of her involvement with Oswald. He subsequently met Francisco Guerrero Garro, the nephew of writer Elena Garro, who introduced Oswald to many in her circle. “We met and saw and spoke with someone who then went and killed the President of the United States,” he said.

Lee Harvey Oswald’s Mexican vacation could have saved President Kennedy’s life. The CIA and FBI were well aware of Lee Harvey Oswald, who traveled to Mexico City in September of 1963, where he visited the Cuban Embassy, and many contend that surveillance photos and other evidence existed but were destroyed by the agencies in order to cover up intelligence failures and preserve counterintelligence assets. Hoover’s successor, FBI Director Clarence Kelley, believed that had the FBI simply acted on the information in their own files, Kennedy’s assassination would have been prevented.