'He's an open book, a tabula rasa," historian Robert Dallek said at the Constitution Center on Nov. 6.

He was speaking of John Fitzgerald Kennedy. The 50-year observance of his murder falls on Friday.

Sadly, inevitably, we have a flood of JFK books. Some are excellent, some pointless, some rehashes of romance (Camelot) and rumor (sex). But there's one thing all have in common. They're symptoms of grief. Symptoms of the need to return.

Vincent Bugliosi, author of Reclaiming History: The Assassination of President John F. Kennedy (W.W. Norton, 1,648 pp., $49.96), means to have the final word. Lee Harvey Oswald did it alone, he says, as did Jack Ruby. Cases closed. In a work rivaling the length of the abridged Warren Report, Bugliosi, with prosecutorial mania, rehearses the evidence, goes through the Zapruder film frame by frame (in unfortunate black and white), with normal and high-contrast images of JFK's head exploding. Bugliosi is driven "to expose, as never before, the conspiracy theorists and the abject worthlessness of all their allegations."

Not attractive - but what he says is probably as close as we can get to what happened.

The problem: No one book can close the book. Too many folks are working like mad, still, on this cold case, such as Colin McLaren, author of the forthcoming JFK: The Smoking Gun (Hachette Australia, 320 pages). The film version was shown on Reelz Friday. McLaren, an Australian detective, believes a Secret Service agent fired one of the shots that killed JFK. This book, to be frank, is as much about its author as its subject, and it hangs by some familiar threads.

Too many institutions still are keeping mum. In the next 10 years, documents will emerge that tell of disarray, trauma, and incompetence. Philip Shenon, author of A Cruel and Shocking Act: The Secret History of the Kennedy Assassination (Henry Holt, 640 pp. $32), comes to the Constitution Center on Monday. He lets us in on the seamy administrative side of the story, the Warren Commission and its many fumbles.

Dallek said on Nov. 6 that he felt the commission, while probably right, did a sloppy job. Shenon shows us how sloppy. What a cast of clowns, fools, bums, and jokers. The most fascinating thing, the thing I'd like to hear more about, is how, and how much, faux-saintly, mysterious CIA counterintelligence chief James Jesus Angleton funneled the flow of information to the commission. We'll probably learn more within the decade. Such revelations won't change much. Team players (FBI, CIA) cover up team mistakes.

There are many worthless JFK books out there. They Killed Our President  is by Jesse Ventura, Dick Russell, and David Wayne (Skyhorse, 368 pp., $24.95). The government killed our Jack and then covered it up. Ventura isn't the host of truTV's Conspiracy Theory for nothing. From the sensationalist title forward, this book piles up the usual suspicions, wild surmises, and fantasies. It whips a personal hobbyhorse and adds little.

Dallas 1963, by Bill Minutaglio and Steven L. Davis (Twelve Books, 364 pp., $17.71), on the other hand, does add some. In Mike Hammeresque vignettes and profiles, the authors remind us of what a political morass was Dallas, and more broadly Texas, and most broadly the United States, at the moment of the Nov. 22 motorcade. Our tossed salad of ultra-right and -left, simmering hatreds, our race psychosis, and Cold War paranoia, all at fevered peaks. Lee Harvey Oswald fit right in.

JFK in the Senate, by John T. Shaw (Palgrave Macmillan, 256 pp., $19.17), is a breezy look at a part of Kennedy's life that should be better known. Pragmatic, canny, cautious, a young politician absorbs all he can, sets up his future career, and goes on the road to prepare for a presidential run. He was a fan of Winston Churchill, a dealmaker, a Cold War man. This helps us understand how he acted as president.

Jeff Greenfield's If Kennedy Lived: The First and Second Terms of President John F. Kennedy: An Alternate History (G.P. Putnam, 272 pp., $18.96), reviewed previously in The Inquirer, does that. It's a "counterfactual" history in which Kennedy survives the shooting. Greenfield suggests Kennedy would have been a successful international negotiator and a very cautious domestic projector.

Further into fiction is PBS guy Jim Lehrer's novel Top Down (Random House, 208 pp., $18.11). The agent who ordered the removal of the Plexiglas top of Kennedy's limousine deals with guilt and PTSD. He learns about fate, love, and fragility. It's a well-told, worthwhile novel.

Where Lincoln and his cabinet had Doris Kearns Goodwin's Team of Rivals, Kennedy now has Camelot's Court, by Dallek (Harper, 512 pp., $22.29). Dallek read from the book at the Constitution Center.

Part of Camelot's Court focuses on Kennedy's occasional bad decisions (think Bay of Pigs). "He was very inexperienced," Dallek says by phone, "very young, and initially he had trust in the men he had appointed to these high positions." It's fair to say he learned on the job. "He learned he simply couldn't take his advisers' advice on face value."

What books do the historians like?

Dallek says Richard Reeves' 1993 book, President Kennedy: Profile of Power (Simon & Schuster, 800 pp., $29.59), is his favorite. Al Felzenberg, who teaches at the Annenberg School for Communication at the University of Pennsylvania, is author of The Leaders We Deserve, and a Few We Didn't. He recommends the 2006 book The Presidency of John F. Kennedy by James N. Giglio (University Press of Kansas, 360 pp., $17.95), a balanced look at physical frailty, sexual compulsion, and real accomplishment.

G. Terry Madonna, professor of political science at Franklin and Marshall College, recommends a new one, The Kennedy Half Century: The Presidency, Assassination, and Lasting Legacy of John F. Kennedy, by Larry J. Sabato (Bloomsbury, 624 pp., $30). Madonna tweets that it's "a marvelous work, splendidly researched and my new JFK fav."

Dallek's excellent 2003 book, An Unfinished Life: John F. Kennedy, 1917-1963, is out anew (Bay Books of Little, Brown, 849 pp., $18 paperback). Dallek, like many of us, revisits Kennedy. Why do we keep going back?

"Because he died so young," Dallek says, "we think of him as the heroic statesman, a martyr."

Ellen Fitzpatrick, a history professor at the University of New Hampshire, edited Letters to Jackie (Ecco, 384 pages, $11.22), a 2010 collection of correspondence to Kennedy's widow. Full of heartfelt sympathy and suffering, it's both devastating and uplifting. "It was like looking at the beating heart of the nation in a moment of historical cataclysm," she says by e-mail.

"We return to JFK because he tapped into a spirit of idealism and soaring aspiration in the American people," Fitzpatrick writes. Kennedy was "our first television president," and "Americans felt they 'knew' Kennedy and his vivacious family."

Greenfield says "the world spent four days in front of a television set, watching a death and its aftermath. It's burned into the consciousness of everyone at the time and is still there."

JFK's death "became a part of the lived experience of millions of Americans," Fitzpatrick writes. "I doubt the memory or interest in it will die even when they do."

215-854-4406 @jtimpane