Gerald Posner is not really an assassination buff, although on the study wall in his high-rise East Side apartment in New York are copies of the guns that allegedly killed John F. Kennedy and Martin Luther King Jr. Those guns figured prominently in his bestselling Case Closed (1993) and Killing the Dream (published by Random House to coincide with the 30th anniversary of MLK's death). There's also a picture of King's accused assassin, James Earl Ray, on an FBI wanted poster, which the author recently bought in an auction conducted on the Internet. But Posner -- a compactly built man with a stylishly cut cap of dark hair, an impish grin, a very quick mind and a nice appreciation of the ironies of so much effort spent unpacking the accretions of time around old crimes -- is quick to insist that there are no more assassinations that interest him. He will not be writing about Sirhan Sirhan and Bobby Kennedy or John Hinckley's attempt on President Reagan. "I tend to concentrate on long-range shooters with a rifle who get away from the scene," he says. "I'm interested in the serendipity effect, how someone turns up all ready to shoot, and the chances that offer themselves, or fail to. I'm sure, for instance, that there must have been other plots to kill King, but Ray was the one who brought it off; and if there hadn't been a room available on the right side of that rooming house, facing the Lorraine Motel in Memphis where King was staying, and if King hadn't spent so long on the balcony, he might never have managed it."

Interest in the book is naturally keen, since Posner's conclusions on the JFK assassination were so controversial. Almost alone among the dozens of authors of hundreds of books on the subject, he became convinced that Lee Harvey Oswald had done the deed alone and unaided -- though there was certainly a lot of covering up that went on later as both the CIA and FBI strove to eliminate evidence of their many errors and inconsistencies.

Because Newsweek had first serial rights to the MLK book, PW only got to read it for review and interview Posner under conditions of strictest secrecy. Once again, the author proves a contrarian. "Most of the books about Ray [who is still in jail, and ill] say he did it as a lone gunman. My view is that there was a conspiracy, but on a very low level. Someone, I'd guess part of a racist group, probably agreed to pay him maybe $25,000 or $50,000, and perhaps we'll never know whether he got any of the money. One of the extraordinary things about the case is that if he'd had access to a bit more money when he needed it, he might have got clean away to South Africa or Rhodesia, somewhere that would have sheltered him, as he said he was trying to do, and we'd never have seen him again."

How did Posner, a lawyer by training, become a full-time writer (and one who earns, he says, more from his many magazine and newspaper pieces than he does from his books)? A political science major at Berkeley, he then went to law school and joined a big firm as a litigation associate. His first case was working on an IBM antitrust suit that had been filed in 1968, six years before he joined the firm. "It was a blessing in disguise," he says. "As a young associate, you make yourself useful by knowing the record" -- and he immersed himself in endless files and briefs. "It made me completely unafraid of paperwork, unlike some journalists," he says. "Boxes of documents are exciting to me, not daunting." And he has, according to his wife, Trisha, a photographic memory that can recall exactly where in a bulging file a paper can be found, and where on the paper a fact can be found.

In 1980 Posner, with a partner, started his own law firm. While working on a pro bono suit on behalf of some survivors of the infamous Nazi Doctor Mengele, he became hooked on the subject and decided to do a book.

In his methodical way, he went to a big bookstore and surveyed the shelves to see who was publishing serious books on history and came up, rather improbably in view of its later trade history, with McGraw-Hill. When he called the house, a meeting was arranged with an editor, and it was agreed that, as a first-time author, he would work with a coauthor. They were offered an advance of $10,000, but, says Posner, "I'd spent more than that already, so I got an agent, Pam Bernstein at William Morris, who got us up to $40,000. I thought she'd been sent from heaven." The book was Mengele: The Complete Story (1984).

He stayed with McGraw-Hill for two more books, Warlords of Crime, about Chinese secret societies, and his first and so far only novel, The Bio-Assassins. Then Bernstein introduced him to Random's Bob Loomis, and the two hit it off and have been together ever since. Posner did later change agents, however, making a switch to Andrew Wylie on his own initiative ("No, I wasn't poached away."). He made one condition: that he wanted to stay with Loomis. "Wylie agreed to that and made the best deal he could, though I think I could have got more elsewhere after Case Closed."

Curiously, although Case Closed ultimately became a big bestseller for Random, the house wasn't interested in the book at first. Posner wanted simply to sift the mountains of evidence once more, not knowing what he would come up with. Loomis was more interested in another idea, which became Hitler's Children, a book about the offspring of Nazi leaders, and that project moved ahead while the JFK book went on the back burner. Ironically, it was the huge success of Oliver Stone's movie JFK (which Posner admires for its skill while deploring what he regards as its obfuscation) that finally kindled the house's interest. "But they were worried when I concluded there was no plot," says Posner. "Harry Evans was a conspiracy theorist -- the mob was behind it." In the end, however, the former Random trade chief was convinced, though his wife, New Yorker editor Tina Brown, told him that "he should be careful, it hadn't been properly checked, the way they would do it at the magazine!"

Caught in the Crossfire

Looking back, Posner agrees that he and Random had been "arrogant" about choosing the title Case Closed -- "though it was certainly provocative." It had been suggested by Trisha, a tall, willowy former fashion model from Britain whom Posner met on a blind date in 1980; they were married three years later and work very closely together. (In fact Posner declares in an effusive acknowledgment note in the new book that "it is as much hers as mine," such are her efforts in researching, interviewing and editing). The furor that followed publication of Case Closed and the death threats that ensued were distressing to both of them. "I expected there would be a difficult time with all the people who were so invested in the idea of some widespread plot to kill the president. What I didn't expect was that people would think I was part of the cover-up myself and that I deserved to die! It was a very bad time."

Still, despite the vituperations of conspiracy theorists (which according to the polls, include most of the American people), Posner is unwavering in his belief that Oswald had no help. "I truly and adamantly believe in Oswald as the sole assassin," he declares. "People think he wasn't smart enough to have done it. I do, and that's why I spent such a lot of time tracing Oswald's life."

Posner also found Ray to be much more interesting than he had expected, and his extensive account of Ray's wretched hardscrabble life and criminal career is, he thinks, the key part of the new book. "His life told you why King died," he says quietly. "I had expected him to be an untalented hillbilly, but in the end I found him quirky enough to be utterly unpredictable: you never knew if he was going to rob a bank or go take dancing lessons."

Posner is fascinated by Ray's bizarre locutions and his frequent changes of his story (he wrote two volumes of memoirs himself, which Posner says are mildly revealing but full of error and falsehood). "When he's asked a straight question, like 'Are you a racist?' he could easily say 'Absolutely not,' but he just rambles around the question, doesn't take the opportunity for the easy lie."

He tried, naturally, to interview Ray in the penitentiary, "but in the end his lawyers didn't want me to see him because he's very sick, and they were afraid he might give something away." Posner has heard frequently, however, from Ray's older brother Jerry, who sends him long, meandering tapes from time to time -- some as recently as two months ago -- as if in mockery of his research efforts, from the trailer where he lives in rural Tennessee with a spare room for "Jimmy" if he should ever get a medical furlough. (Another brother, John, remains utterly mum.)

Parts of Jerry's tapes are played for PW. In a deep voice sounding a little befuddled with bourbon and punctuated by husky chortles -- "heh, heh. heh!" -- and the sound of gobs of tobacco juice being projected into a spittoon, Jerry Ray meanders about possible witnesses, sings a bit of a song about "my old Chevrolet" and declares: "This will be a government propaganda book, and if that's the way it is, it will be a total flop.... If your book is full of bullshit I will challenge it, Posie-Wosie."

Posner listens with keen attention, chuckling from time to time. "He's either very clever or very dense. He likes to pose as the family clown who couldn't be trusted with secrets, but even when it was clear I wasn't going to use anything he told me, he told me a bunch of lies anyway. His motive was obviously to have me put things in the book that he could prove wrong later."

Problems with the Ray family are not uncommon among those who write about the case. The late George MacMillan, from whose The Making of an Assassin (Little, Brown, 1976) Posner acknowledges having drawn extensively, worked closely with the family in the years following the assassination. He seems to have secured their trust and to have learned some valuable and true things from them about James, but later they turned against him, denying the truth of much of what they had earlier revealed.

"MacMillan's archives were invaluable to me, but what later went wrong for him was partly his fault, for paying the Rays to talk to him." Posner is adamant that no money must ever change hands in the writing of a book. "It's a disastrous thing to do, though I'm sure we may have lost good sources as a result."

The experience with publishing Killing the Dream was not unlike that of the JFK book in one important respect. Random did not at first seem interested but changed its tune after members of King's family, particularly his son Dexter, came out in public protesting that Ray was innocent, asserting that their father had been killed by unknown conspirators in the pay of the government, possibly by an Army hit team. Just as Posner had written Hitler's Children to fill in a previous gap before Random would greenlight Case Closed, so this time another project-Citizen Perot, about the Texas billionaire who became a presidential candidate-was rushed into the breach until Random was ready to publish the King book. Posner is perplexed by the Kings' attitudes. "I wouldn't worry if they felt there was a much bigger plot, though I still wouldn't think they were right," he says. "But they shouldn't exonerate Ray."

Killing the Dream, with its exhaustive research, was completed, in time for the 30th anniversary of King's assassination, in a little less than two years, and Posner is understandably a bit weary, though not without ideas for his next project. He expects this will be a study of Motown and the black music business in Detroit in the 1960s, and the ways in which the Mafia became involved with it. "I think of it as a popular piece of social history, offering commentary on a lot that was going on in America in the '60s. I'm not sure how it fits in with the rest of my work, though -- perhaps I'm on a sort of sabbatical."

And, yes, he's thought of further fiction efforts, where his endless research might come in handy. "I have all these notions," he says with a gleam in his eye, "about national plots and assassinations."