LATE ONE night in January 1991, I got a call informing me that a close friend, researcher Greg Stone, had committed suicide. Because I had talked to Stone, who seemed fine, earlier that day, the news seemed impossible to believe. Five days later, after I returned home from his funeral, I received a signed note from Stone in the mail that simply said, "Sorry about this, Dan. Stay a survivor."

Stone and I had met during the summer of 1985 while I was living in Los Angeles, working on a book. A long-time aide to Allard Lowenstein, the former New York congressman who had been murdered in 1980, Stone had been trying to reopen the investigation of the murder of Sen. Robert F. Kennedy. Because of my background as an organized crime investigator, Stone wanted me to get involved in the case.

Kennedy had been shot and mortally wounded in the early morning of June 5, 1968, in the Ambassador Hotel in Los Angeles. Just moments earlier, the 42-year-old Kennedy had left a celebration in the wake of winning the California Democratic presidential primary. No fewer than 77 people were crowded in the narrow kitchen pantry when 24-year-old Palestinian immigrant Sirhan Bishara Sirhan, using an eight-shot .22 caliber revolver, opened fire. Kennedy was shot three times and died early the following day. Five other people were each shot once but all survived.

At our 1985 meeting, Stone explained that evidence of a possible second gunman was based, in part, on an official FBI report that indicated more shots had been fired than Sirhan's gun could hold.

In addition, Kennedy's wounds, according to a thorough autopsy, came from shots fired at point-blank range -- six inches or less. However, not a single eyewitness saw the muzzle of the shooter's gun get anywhere near that close.

Also, a court-appointed firearms panel that had refired the murder weapon seven years after the shooting could not match the intact bullets removed from Kennedy and two of the other victims with Sirhan's gun.

And, Stone told me, Thane Eugene Cesar, a security guard with extreme right-wing views, who hated Kennedy, was standing next to the senator at the moment of the shooting and had a gun in his hand and powder burns on his face. When I began to read the limited amount of available documents concerning the assassination, I was shocked by what I saw. Without question, the case I had always assumed was open-and-shut had been badly mishandled by the Los Angeles Police Department, particularly with regard to crime scene evidence. It was clear that law enforcement officials had misrepresented key facts in the case, destroyed material evidence and obstructed independent attempts to resolve the critical issues surrounding the case.

Helping to perpetuate doubts about the official investigation was the fact that the LAPD's case file had remained hidden. Promises to release these 50,000 documents began as early as the end of the Sirhan trial when District Attorney Evelle Younger said, "The Los Angeles Police Department has agreed without reservation that the interests of the public and law enforcement are best served by full disclosure of the results of the comprehensive investigation which they have conducted."

But full disclosure had not come. And evidence that had not been tampered with made it seem unlikely that Sirhan was the only person to fire a gun that night. Stone prompted me to write an investigative piece about the unanswered crime scene questions. My first effort appeared in the June 1987 issue of Regardie's.

In addition to examining the inconsistencies in the official version of the killing, the story also contained my exclusive interview with security guard Gene Cesar.

That same June, the city of Los Angeles reversed the LAPD's position, ordering the immediate release of the entire Robert Kennedy murder case file. And on April 19, 1988, with a minimum of censorship, the RFK case file was made public in a microfilm edition. However, on the day of the release, California state archivist John Burns announced that 2,410 photographs -- with subjects unknown -- had been inexplicably burned by the LAPD on August 21, 1968, just three months after the murder and nearly eight months before the conclusion of Sirhan's trial.

Also missing from the files were numerous items from the crime scene, as well as the taped statements of 51 key witnesses, including 29 with accounts that related directly or indirectly to questions of conspiracy.

In the midst of widespread criticism, the LAPD remained unrepentant and even defiant. Regarding the release of the files, former LAPD chief of police Ed Davis told UPI, "It's like opening up a collection of pornography to a bunch of sex-hungry pornography addicts. They're going to fondle the gun, touch the wood, stick their fingers in the bullet holes, and read all the reports. But there isn't going to be much there."

Indeed, there wasn't. But although it was immediately evident that the LAPD files in the case were incomplete and that valuable evidence and records had been destroyed, Greg Stone convinced me that there was enough new information to draw me back into the investigation.

My first stop in Los Angeles was Parker Center, headquarters for the LAPD. I had earlier given my Regardie's article to three homicide detectives, whom I had used as sources for my previous work, and asked for their opinion of my story. In essence, these officers criticized the article because I had relied too heavily on the testimony of eyewitnesses who lacked the experience necessary to make their stories credible.

Instead, I started to conduct a series of interviews over the next several months with the people whose training and experience would be beyond dispute: the officials, detectives and patrolmen in the LAPD, the Los Angeles Sheriff's Department, the Los Angeles Fire Department and the FBI who performed their routine duties at the crime scene after the shooting.

Of the 187 principal law enforcement officials, detectives and officers identified in LAPD records as having been involved in the 1968 Kennedy crime scene investigation, I was able through my contacts to locate or learn the fate of 158 of them. A total of 114 agreed to be interviewed and speak on the record.

Virtually none of these law enforcement professionals had ever been interviewed about the Kennedy case. During our conversations, most of them were honest and unguarded in their responses to two basic questions: "What did you do?" and "What did you see?" Many officers had kept their field officer's notebooks, and some even referred to their notes during my interviews.

Several LAPD and L.A. Sheriff's Department officers told me that during the 105 minutes after the shooting, from 12:15 a.m. to 2 a.m., when the LAPD's crime lab took control of the area, they saw or heard about evidence of what they believed to be bullet holes in the walls and door frames in Sirhan's line of fire. Other LAPD officials and officers told me that they believed that they had also seen bullet holes at the same location.

With its own crime scene report, the FBI had essentially made a case that at least two guns had been fired the night of the murder. And now officers and officials of the LAPD were corroborating the FBI's findings.

The preliminary results of this investigation were contained in an Outlook article that appeared on these pages five years ago. In the article, I concluded: "{I}t would be a mistake to rush to quick or simplistic judgments concerning the origin of additional assassination gunshots. The importance and complexity of this matter demand that it be examined impartially by a reconstituted official investigation."

On the basis of the new evidence, Greg Stone, just two months before he killed himself, sent a letter to Ira Reiner, the new Los Angeles County district attorney, requesting a grand jury investigation into the police investigation of Kennedy's death.

Because I am an independent journalist, personal and professional restrictions forced me to fade in and out of the case, depending on how much time and money I could afford to spend satisfying my curiosity: Do we really know the truth about Robert Kennedy's murder? It was not until I received the backing of a major publisher that I could do what was necessary to resolve my own questions about this case.

I continued to study the case file; I continued my interviews with law enforcement officials. At last, I arranged for Cesar to be polygraphed. He passed -- the first indication that my "plot" was taking an unexpected turn. It became clear to me that an innocent man had been wrongly accused of involvement in murder for over 25 years. I also began to learn how the physical evidence might have been misunderstood; for example, the "bullet holes" in the door frame could have been mislabeled by a sheriff's deputy who lacked expertise in ballistics and firearms identification.

I had not abandoned the idea of a second gunman, but realized that Sirhan himself had become my last hope for conclusive proof of a second gunman or other co-conspirators. I guess I had known all along, whether I fully realized it or not, that this entire case would begin and end with him. The six-hour interview between us in September 1993 went well, as did my second four-hour interview two weeks later. In each session, I recounted my work in the Kennedy murder case -- which he was already well aware of -- that indicated that two guns had been fired at the crime scene. For the most part, I had been lobbing softball questions, allowing him to smack them over the fence.

My third interview with Sirhan occurred on June 5, 1994. Assuming that this would be my last formal interview with Sirhan, I decided to go over some of the same ground we had covered during the previous two interviews and then to go for his throat to see how he would react.

Deep into the interview, I again took Sirhan through his day on June 4, 1968.

He recalled leaving a practice gun range during the late afternoon, wandering through Pasadena, searching for a party in downtown Los Angeles, arriving at the Ambassador and drinking Tom Collinses at a party for Republican senatorial candidate Max Rafferty; then, after going back to his car, returning to the Ambassador for coffee.

"At that point," Sirhan told me. "I blacked out."

Sirhan has always maintained that he had been drunk on the night of the shooting and does not remember either firing his weapon or even seeing Kennedy.

I asked him, "You don't remember anything about the shooting?"

"No, nothing," Sirhan replied. "It just isn't in my mind. I just remember being choked {by those at the crime scene trying to subdue him}."

"Do you think the contributing factor to your memory loss was the fact that you had drunk too much that night?"

"I didn't know anything about beers or liquors. I was a square. The Tom Collins tasted just like lemonade. I was tired. It was late. I was an early-to-rise, early-to-bed person. I was out of my element. Whether I was drunk, programmed or out-maneuvered, what has happened has happened. They never gave me a breathalyzer, and they only drew my blood the next day \. \. \. ."

"Then, once again, why don't you just accept responsibility for this crime?"

"If I was to accept responsibility for this crime, it would be a hell of a burden to live with -- having taken a human life without knowing it."

"Then you are saying that you are willing to take responsibility, but you have no memory of committing the crime?"

"It's not in my mind, but I'm not denying it. I must have been there, but I can't reconstruct it mentally. I mean no disrespect here, but I empathize with Senator Ted Kennedy in the Chappaquiddick incident. He was supposedly under the influence of alcohol and couldn't remember what he had done. When he finally did realize what had happened, someone was dead."

"Why did you take credit for the murder at your trial?"

"{Sirhan's defense lawyer} Grant Cooper conned me to say that I killed Robert Kennedy. I went along with him because he had my life in his hands. I was duped into believing that he had my best interests in mind."

"You were willing to go to the gas chamber for a crime you didn't remember committing?"

"I did a lot of self-exploration while I was on death row. It changed my whole vision of the world. I was trying to justify that I was going to the gas chamber. I wanted to search myself to find the truth, but I could never figure it out. I had nothing to lose."

"Did you ever examine whether you had acted with premeditation?"

"When I got to death row, I started reading the law about diminished capacity and the requirements for premeditation. There was no way that I could have summoned the prerequisite for first-degree murder. That was no part of me. They said that I didn't understand the magnitude of what I had done. They're right. I don't truly appreciate it, because I have no awareness of having aimed the gun at Bobby Kennedy."

"Why did you admit to the murder before the parole board?"

"They want the prisoner to admit his guilt and take responsibility for the crime. They want us to confess and to express remorse, which is what I have done. In fact, I have been told that I won't be paroled because of the Kennedys."

"So, once again, you were willing to take credit for the crime without remembering that you had committed it?"

Sirhan then seemingly became overwrought, exclaiming, "It's so damn painful! I want to expunge all of this from my mind!"

As if I had been punched with a straight right hand, I suddenly thought to myself: This guy has been lying to me all along.

"I am not a court of law," I told Sirhan. "I am not a parole board. I'm a reporter who doesn't want to be wrong. I want to know, Sirhan: Did you commit this crime?"

Sirhan fired right back, "I would not want to take the blame for this crime as long as there is exculpatory evidence that I didn't do the crime. The jury was never given the opportunity to pass judgment on the evidence discovered since the trial, as well as the inconsistencies of the firearms evidence {the bullet evidence} at the trial. In view of this, no, I didn't get a fair trial." With that reply, I finally began to understand Sirhan's strategy: As long as people like me continued to put forth supposed new evidence, he still had a chance to experience freedom. And I also understood why he was talking to me in the first place. More than any other person in recent years, I had been keeping this case alive.

At that moment of my stark realization in that prison visitation room, I barked at Sirhan, "You don't remember writing in your notebooks in which you articulated your determination to kill Robert Kennedy and why -- That's motive! You don't remember getting your gun when you returned to your car from the Rafferty party -- That's means! You don't remember having been in the pantry, getting close to Kennedy, and firing your gun -- That's opportunity! "Every time you have a memory lapse, it goes to motive, means or opportunity!"

In response, Sirhan sat quietly, saying nothing but looking puzzled, probably wondering where the hell I was going with all of this. But I could tell that he wasn't concerned. He knew, probably more than anyone else, that I had bought into the second gun theory and made a good case of it. "What's Moldea going to do now that he's in so deep?" Sirhan must have been thinking.

Knowing how close Sirhan was to his ailing mother, I asked him, "Sirhan, when your mother dies, God forbid, are you going to remember everything and come clean?"

Furious with me for having brought his mother into this, Sirhan exclaimed, raising his voice with each syllable, "Change my story? Mr. Moldea, you're a {expletive}! Mr. Moldea, you're a {expletive expletive}!"

I smiled at Sirhan and started jabbing my finger in his face. "Sirhan, it's Dan, you're a {expletive}. Dan, you're a {expletive expletive}.' " As I started to laugh out loud, Sirhan paused for a moment and started laughing, too, breaking a very tense moment.

But he wasn't laughing for the same reason I was. I had just wanted Sirhan to remember the first name of his last hope. Dan Moldea's most recent book, "The Killing of Robert F. Kennedy: An Investigation of Motive, Means and Opportunity," is being published this month by Norton.