As a witness to the revolution that Pope John Paul II unleashed in the minds of his fellow Poles, I am especially eager to know whether the conspiracy against his life can ultimately be traced back to the Kremlin.

When the pope was shot in St. Peter's Square on May 13, 1981, I was living in Poland, absorbed in the amazing story of what amounted to a peaceful uprising against 35 years of communist rule. I saw the enormous role played by the first Polish pope in history in reviving the nation's self-confidence and acting as a kind of spiritual godfather to the independent Solidarity trade union.

When John Paul II was shot, Poland palpably shuddered. It was as if a light in the national psyche had flickered and almost died. When it became clear he would live, the light came on again.

When allegations first surfaced of a possible "Bulgarian connection" to Mehmet Ali Agca, the pope's Turkish assailant, the hypothesis of a Kremlin-inspired conspiracy seemed plausible to me. I had no difficulty accepting the proposition that, if Moscow's most loyal ally in Eastern Europe was implicated in this affair, then so too was the Soviet Union itself.

By last June, after an Italian state prosecutor formally accused the Soviet bloc of attempting to murder the pontiff, I had moved from East to West Europe. The Washington Post assigned me to the story. Looking into Agca's background, I traced his footsteps to St Pete's Square by way of Turkey, Bulgaria and Italy. I talked to his former associates and alleged co-conspirators, interviewed lawyers and magistrates and sifted through thousands of pages of Italian and Turkish legal documents.

I was following a real-life detective story. I discovered that there is a circumstantial case to support the theory of a "Bulgarian connection," but it hangs on the statements of Mehmet Ali Agca, a confessed liar who continued telling demonstrable lies to the Italian authorities even as he "confessed" the Bulgarian connection. There is also a circumstantial case against the theory of a Bulgarian tie to the attempted assasination. Given the potential political significance of this legal case, both possibilities deserve further exploration.

One of the attractions of the Soviet bloc conspiracy theory is that it seems to provide an easily understandable motive for the murder of a pope. It is difficult to underestimate the fright the Kremlin received in 1980-81 with the rise of Solidarity. Once the genie of democracy had been allowed to escape in Poland, Moscow's alternatives were stark. Either the genie had to be stuffed back into its bottle or it would devour the country's monolithic communist institutions, thus threatening the stability of all of Eastern Europe.

Why not simply remove the man who was at once a symbol of Poland's national identity and a source of inspiration for millions of discontented Polish workers and farmers? And why not use the Bulgarian secret service, Darzhavna Sigurnost (DS) -- an agency unafraid to commit murder, and which the KGB supervises closely -- to accomplish this objective?

From Moscow's perspective, Agca could easily have been the ideal choice as papal assassin. With the exception of a six-week stay in Bulgaria in the summer of 1980, there is nothing in his background to suggest a Soviet bloc connection. In Turkey, he was associated with an extreme right-wing terrorist group known as the Gray Wolves.

Arrested on suspicion of murdering a liberal Turkish newspaper editor in February 1979, he managed to escape from prison in Istanbul with the help of fellow right-wing terrorists.

In fact, it is possible to demonstrate a clear chain of relationships connecting Agca and the Bulgarian secret service -- and thus, by extension, the KGB. The Gray Wolves were connected at several different levels with an international gang of smugglers known as the Turkish mafia upon whom they relied for arms and funds. The mafia in turn conducted much of its business through Bulgaria -- with the complicity of that country's communist authorities.

After the Turkish military seized power in September 1980, alarming evidence came to light of Bulgaria's involvement in a vast traffic in weapons and ammunition to both left and right in Turkey. In addition to the Soviet bloc's ideological interest in fomenting political instability in a NATO country, the arms trade appears to have represented a valued source of revenue for the Bulgarian authorities, who took a cut of the money earned by hundreds of Turkish smugglers who operated through Sofia.

Agca has told Italian magistrates that he was introduced to Bulgarian agents in Sofia by influential members of the Turkish mafia with whom he had been in contact during his Gray Wolf days in Turkey. Logistical support for the attempted assassination of the pope, Agca said, was provided by three Bulgarian officials in Rome and a network of Turkish rightists in western Europe.

There seems no doubt that Agca did indeed spend the better part of July and August 1980 in Sofia. Even accepting the fact that he was travelling on a false Indian passport, it is difficult to explain how one of Turkey's most wanted terrorists could have spent such ane extended period in the Bulgarian capital without attracting the attention of the authorities -- unless, of course, the DS knew all about him already.

Evidence for a relationship between Agca and the three Bulgarians he has named as his "controls" in Rome is provided by his ability to give Italian investigators accurate details about their movements, personal characteristics and hobbies. Agca first identified his Bulgarian accomplices on Nov. 8, 1982, when he was shown an album containing 56 photographs, labelled simply by numbers.

The investigating magistrate, Judge Ilario Martella, described what happened next in his formal 1,432-page indictment filed in court last month: "Without [Agca] being informed in any way of the names or the positions of the people he had to pick out, this judge asked him if he had "ever known any of the people in this album"; to which Agca replied by claiming that he could identify with certainty the Bulgarians Sotir Kolev and Bayramic in the photos numbers one and two (about whom he had talked in previous interrogations) and a third Bulgarian known to him by the name of Sotir Petrov in photo number 20 to whom he was making reference for the first time, precisely now that he was able to recognize him."

The names given by Agca were code-names, whose accuracy cannot be tested. But he was also able to tell investigators that "Kolev's" first name was really Todor, that he had been in Sofia in July 1980 (when Agca said they met), that Petrov worked in the Bulgarian embassy in Rome, "probably" in the military attache's office, that "Bayramic" wore glasses, and that all three Bulgarians had been in Rome on the day the pope was shot.

All these details turned out to be correct. Agca later went on to give the judges a mass of other information about his accomplices ranging from the fact that "Petrov" had a tiny mole on his left cheek to the kinds of cars the Bulgarians drove to a description of their private apartments. Among the telephone numbers he gave for the Bulgarian embassy was one which was not even listed in the telephone book.

Since the Bulgarians accused of complicity in the assassination attempt deny ever setting eyes on Agca, the simplest explanation for the Turk's ability to provide all these details is that he is speaking the truth when he claims to have had dealings with them. The state's case is that, in the absence of any other plausible explanation for these dealings, Agca can also be believed when he says that he conspired with the Bulgarians to kill the pope.

A further boost to Agca's credibility is provided by his description of a plausible escape plan involving a diplomatically sealed truck in which he and a Turkish accomplice were to have been smuggled out of Italy. Such a truck was in fact at the Bulgarian embassy at the time of the assassination attempt. The importance of the truck for the plot is illustrated by the fact that, according to the prosecutor, the Bulgarian embassy resorted to quite exceptional customs procedures in order to clear it.

Judge Martella seems to have been totally unconvinced by elaborate alibis provided by the Bulgarian defendants for the period of the assassination attempt. Martella presents plausible evidence that Bulgarians employed at the embassy and the Bulgarian state airline Balkanair coordinated their testimony. Some Italian witnesses gave inconsistent testimony; others contradicted the versions given by the Bulgarians, and one, a circus manager, said his meeting with one of the Bulgarian accused that was part of the Bulgarian's alibi had actually taken place six months after the date claimed by the defense.

The Italian prosecutor, Antonio Albano, concluded that: "In some secret place, where every secret is wrapped in its turn by another secret, a politician of great power . . . made a decision, in accordance with the higher interests of the Soviet bloc, that it was necessary to kill Karol Wojtyla [Pope John Paul II]." In his report, Martella, the investigating magistrate, stopped short of connecting the papal plot with the Soviet Union or events in Poland. He avoided accusing any government of a role in the plot.

The biggest, most striking flaw in the argument for a "Bulgarian connection" to the papal assassination attempt is the personality of the man upon whose "confessions" the whole case hangs: Mehmet Ali Agca himself. It is hard in fact to imagine a more unreliable informant than this 26-year-old convicted killer and proven perjurer.

Agca can be shown to have lied literally hundreds of times to judges both in his native Turkey and in Italy. During two years of interrogations by Italian magistrates, he changed the details of his story virtually continuously. He has admitted describing meetings that never took place attended by characters invented off the top of his head. He has also acknowledged that he made up non-existent incidents about the three Bulgarian officials in Rome and a member of the Turkish mafia whom he has depicted as his principal accomplices.

When questioned by Judge Martella about obvious lies and contradictions in his previous testimony, court records show that Agca gave differing explanations. His excuses range from temporary memory lapse to a desire to give greater credibility to his accusations against the Bulgarians to a wish to protect his Gray Wolf associates to the sheer psychological difficulty of telling the truth for someone so accustomed to lying. On each occasion, he invariably promised to cooperate unreservedly with the Italian justice authorities in the future, but he kept on lying.

The scale of the changes made by Agca in his own testimony is reflected in his final interrogation which took place on Jan. 27, 1984. During the session, he was invited to read over all his previous interrogations and point out any untruths. His corrections, retractions, and clarifications run to no less than 121 pages -- the full transcript of which is contained in Martella's final report.

One of the more glaring examples of totally invented evidence by Agca, described by Martella as "grotesque," is his description of a meeting with a military attache of the Soviet embassy in Teheran, "Vladimir Kuzintski." Agca claimed that he discussed plans with Kuzintski for a variety of terrorist acts including killing the American hostages or Iranian leaders including the Ayatollah Ruhollah Khomeini.

Here is Agca admitting to Martella that he lied about Kuzintski: "In fact I have never known such a person. I was able to find out his name and his function from reading the newspapers which spoke about him because he applied for political asylum in a western country, in England, where I believe he still is. I, lying, talked about relations I had with this person because I felt that the Western press could do more to convince world public opinion that the attack on the pope -- which wax executed by me on the orders of the Bulgarian secret services -- was in reality piloted by the Soviet Union."

In order to make his relationship with Kuzintski more convincing, Agca later admitted, he had invented a non-existent Bulgarian secret agent called "Malenkov" who allegedly acted as his go-between with the Russian. Agca had also falsely claimed that the Soviet military attache had supplied him with a fake passport.

This was hardly the only episode which Agca invented. In order to smooth out various contradictions in his testimony, Agca has also been compelled to retract a series of other incidents ranging from a description of a strategy session in the apartment of one of the Bulgarians three days before the assassination attempt to his claim to have accompanied another of his alleged Bulgarian accomplices on outings to the horse races.

Agca mixes reality with fiction. The difficulty of sorting out the lies from the truth is acknowledged by Martella, who notes the Turk's "devilish ability, displayed many times, to produce well-constructed, fantastic, and incredible stories." In another passage of his report, the judge concedes that Agca could have a personal and idealogical interest in making accusations against Bulgaria and the Soviet Union, presumably because of his right-wing Turkish background.

A second major flaw in the "Bulgarian connection", as described by Agca, is the carefree incompetence with which the Bulgarian agents are alleged to have acted. Granted, secret services have been known to suffer from overconfidence and behave in strange ways. It could be argued that, if the CIA could seriously consider attempting to discredit Cuba's Fidel Castro by making his beard fall out, then there is nothing farfetched about the Bulgarian DS conspiring with a bunch of right-wing Turks to kill the pope. The problem with this particular plot, however, is that the plotters seem to have taken practically no precautions at all to keep what they were up to secret.

If Agca is to be believed, he socialized with his Bulgarian co-conspirators, visiting with them at their homes and accompanying them on shopping expeditions. To contact his principal Bulgarian control, he simply telephoned the embassy, apparently oblivious to the posibility that the phones might be bugged. Meetings were held in some of Rome's best-known restaurants and bars.

This shows at the very least an appalling ignorance of what is known in the intelligence business as "tradecraft." As a veteran CIA hand, William Hood, noted in a recent article in the magazine Problems of Communism: "Agca's activities show no evidence of careful preparation, secrecy or compartmentation. In fact, the Bulgarian association with Agca was so ill-concealed that even the notorious cinematic bungler Inspector Clouseau might have detected it."

The same thought apparently crossed Martella's mind. At one point in the interrogation, he specifically asked Agca about his claim to have met with the Bulgarians several times in the same busy bar near the central railway station. Did it never occur to anybody that there was a danger of being recognized if, as in fact happened, one of them was later captured?

Agca replied: "We excluded such a possibility in view of the fact that this was a place on two different floors and the waiter only paid attention to our orders."

On the day of the shooting itself, Agca says he was accompanied to St. Peter's Square by all three Bulgarians accused. One, Sergei I. Antonov of the Balkanair national airline, took the trouble to put on a false beard "because of his numerous everyday contacts in Rome." It was Antonov's job to drive the getaway car, an Alfa 2000 hired from Hertz, which he parked in the busy Via della Conciliazione which leads down to the River Tiber from the Vatican.

It proved impossible for the investigators to find any trace of the Hertz rental car mentioned by Agca. Nor could they find any trace of the 3 million West German marks ($1.4 million) which Agca says he and his friends were paid to kill the pope. No witness has come forward to confirm any of the meetings between Agca and the Bulgarians. Neither has any witness been found who could testify that Antonov or any of the other Bulgarian accused spoke more than a few words of English -- the language which according to Agca, was their only common means of communication.

Elementary logic might have induced the Bulgarian secret service to get their agents out of danger right after the assassination attempt. This did not happen. All three Bulgarian defendants stayed on in Rome for many months, despite mounting press speculation about a "Bulgarian connection" to the papal plot. Antonov was still in Rome 18 months later, on Nov. 25, 1982, when Italian police arrested him.

Italian magistrates have yet to release evidence to support the prosecutor's contention that the bulgarian embassy resorted to "exceptional" customs procedures to clear a specially sealed truck at the time of the assassination attempt. Bulgarian officials say that such trucks called at the embassy half a dozen times a year. The fact that a truck was at the embassy on May 12-13, 1981, was first pointed out by the defense lawyers -- not the prosecution -- in an attempt to establish an alibi for one of the Bulgarians.

As for the chain of contacts between the Gray Wolves and the Bulgarian secret service, this proves little in itself. The real question is not whether they can be shown to have had dealings with each other, but who was using whom and for what purpose.

There is convincing evidence that the Gray Wolves used the Turkish mafia to smuggle Agca out of Turkey in the summer of 1980 after he escaped from prison in Istanbul. A perfectly plausible case can be made out that the mafia then used its network of contacts in Bulgaria to hide Agca in Sofia before he began his long trek across western Europe. It is impossible to know whether the Bulgarian authorities were aware of Agca's real identity -- and, if so, at what level. Conceivably, Agca might have met some members of the Bulgarian secret service at this time, though, apart from his own testimony, there is absolutely no evidence of this.

The motive that has been raised for a Soviet-bloc connection to the papal plot also poses problems. It is by no means certain that the murder of the pope would have removed the religious inspiration for Solidarity, as the Soviets are said to have hoped. In fact, by providing the Polish people with the most prominent martyr in their history, it might have done just the reverse.

Another problem involves the date when, according to Agca, the plot was originally hatched -- July-August 1980, a month before Solidarity even existed. Would the Soviets have mounted such a high-risk operation against a still-hypothetical danger? And Agca himself first threatened to kill the pope in letters to a Turkish newspaper in November 1979 following his escape from prison.

Martella's conclusion that the Bulgarians got together to coordinate their testimony is plausible. The Bulgarian defendants have said that, in an effort to reconstruct what they were doing on a long-forgotten day which had no particular significance for them at the time, they discussed their "alibis" among themselves. But even if the alibis turn out to be totally artificial (a point the defense lawyers vigorously contest), we are left wondering what that really means. Offering false alibis may raise our suspicions, but does it prove a Bulgarian connection to the assassination attempt?

The case for the Bulgarian connection, as described by Agca, is weakened by a close analysis of the way in which the pope's would-be assassin supported his claim to have a personal relationship with the three Bulgarians accused. It is possible to demonstrate that he could have learned many -- though not all -- of the details that he provided to the judges about his alleged accomplices during the course of the three-year investigation itself.

Agca's initial testimony about the three Bulgarians is notable mainly for its sparseness. Much of it was to be contradicted anyway by his later statements. As the investigation proceeded, and more information became available to Agca from the Italian mass media and confrontations with other witnesses and suspects, the detail with which he described the plot became increasingly more intricate.

Take, for example, Agca's testimony about Antonov, the only Bulgarian defendent in Italian custody.

According to the chronological account in Judge Martella's indictment, Agca referred to Antonov for the first time at the end of October 1982 -- nearly six months after he began "cooperating" with the Italian authorities. The initial reference was brief. He said that, while talking to his Bulgarian control officer "Sotir Kolev" on May 12, 1981, in the vicinity of the Hungarian airlines office in Piazza della Republica, he noticed the presence of a man aged about 30 with a somewhat lank face, a blondish (possibly false) beard, and glasses which he kept in his jacket pocket but occasionally put on. It was agreed that the next day, May 13, this man would be waiting with an Alfa 2000 in the Via della Conciliazione to help him and "Kolev" excape after assassinating the pope.

On Nov. 8, 1982, Agca identified the driver of the escape car as the man in the second photo in an album of 56 Bulgarians shown him by his interrogators. "Kolev," he remembers, had called the young man "Bayramic." This time Agca describes "Bayramic" as having a black, not a blondish, beard "which seemed to me fake" but which he had been wearing for the lst two or three days -- thus contradicting his previous testimony that he had only met "Bayramic" a day before the assassination attempt.

Agca was able to provide the judges with a much more detailed account of "Bayramic's" facial features on Nov. 19 -- 11 days after being shown his photo. His accomplice, he now remembered, had a "broad forehead" and a "nose which is slightly bigger than normal." Agca again revised his testimony of both how and when he and "Bayramic" first met. He now put the original introduction back to December 1980, and said it wasn't "Kolev" who had introduced them, but another Bulgarian agent, "Sotir Petrov." And this time the meeting occurred at the Hotel Archimede in Rome, when they purportedly discussed plans to assassinate Polish Solidarity leader Lech Walesa. (Originally, Agca gave Italian authorities an elaborate account of the supposed plot against Walesa, but later he retracted key elements of his tale, and Judge Martella has now closed his investigation into that matter.)

Having earlier said he was unable to remember any telephone numbers for the Bulgarians, Agca then rattled off a string of numbers which he said he used to contact "Bayramic," "Kolev" and "Petrov." They included numbers for Balkanair, numbers for the Bulgarian embassy and numbers for two private apartment blocs owned by the Bulgarians in Via Galiani.

It later turned out that during the course of the Nov. 19 interrogation, Agca had been allowed to consult a Rome telephone directory by the court-appointed Turkish interpreter. The telephone numbers cited by Agca were all listed in the directory with the exception of one: 360-9645. He might have guessed, however, that this number belonged to the Bulgarian embassy, since numbers on either side of it, including 360-9643 and 360-9648, which he also cited, appear in the book under the embassy's listing.

By Nov. 27, two days after Antonov's arrest, Agca came up with a third version of how he and "Bayramic" first met. Brought face to face with Antonov by the judges, he now said they had been introduced to each other in Kolev's apartment at Via Galiani 36. By late December, he was claiming to have held a meeting with Antonov and his wife at their own apartment a couple of days before the assassination attempt -- a claim he retracted on June 28, 1983.

Asked in his last interrogation in January 1984 to state exactly how he had first met "Bayramic," Agca reverted to the Nov. 19 story that he had been introduced to him by "Petrov." But the site of the alleged meeting had been changed: "in the Piazza Barberini, if I am not mistaken."

A similar pattern can be observed in Agca's statements about the two other Bulgarian accused: Todor S. Aivazov ("Kolev") and Maj. Zhelkyo K. Vasilev ("Petrov"). His initial description of Aivazov was wildly inaccurate -- but improved after a press conference in Sofia on Dec. 17, 1982, at which Aivazov was present, and which was reported, with photographs, in Italian newspapers and on television. As the investigation proceeded, Agca's knowledge about the two men expanded. But he frequently contradicted himself and made mistakes which he later corrected.

Antonov's defense lawyers have argued that Agca must have been "fed" information about the Bulgarians either before or after his arrest. Judge Martella specifically rejected the charge that Italian authorities could have guided Agca while he was in prison.

A close examination of Agca's testimony suggests that it may not be necessary to construct a new conspiracy theory to explain how the pope's would-be assassin came by his knowledge of Antonov and the other Bulgarians. Given his proven ability to mislead investigators in both Turkey and Italy, and the fact that he was able to watch television and read Italian and Turkish newspapers in his prison cell, it is quite conceivable that he invented the entire Bulgarian connection with very little help from outside.

Take, for example, the tiny wart on Vasilev's face. The Italian prosecutor points to Agca's ability to recall this detail in mid-1983 as evidence that the pope's would-be assassin must have known Vasilev -- despite the awkward fact that Agca's memory of Vasiliev's height was off by about seven inches. To support this argument, the prosecutor said that Vasilev's wart "cannot be seen in photographs." In fact, it is quite clearly visible in Italian television news film of the Sofia press conference.

Agca did, it is true, provide some details about the Bulgarians that still cannot be explained away. For example, how he knew as early as November 1982 that Aivazov's first name was Todor? And how could he tell the judges that Vasilev was "presumably the military attache at the Bulgarian embassy in Rome"? Or know the detail -- which Agca first mentioned in July 1983 and was later confirmed by Antonov himself -- that Antonov liked collecting miniature liquor bottles?

The number of such inexplicable details is less than a dozen, however, and has gradually been whittled down as we have learned more about the sources of information to which Agca had access. A couple more revelations like the extraordinary admission that Agca was able to consult a Rome telephone book in prison and the mystery may be solved.

Without full access to all the evidence gathered by Judge Martella during the course of his three-year investigation, it is impossible to prove or disprove the "Bulgarian connection." Such an exercise would probably be futile anyway. As with most complex legal cases, this one will no doubt be decided by the court's assessment of the balancve of probabilities rather than conclusive proof one way or the other.

Despite the assumptions of many commentators and politicians, particularly in America, that the Bulgarian connection has been virtually "proven," it has not been. The case is circumstantial, and depends entirely on information provided by a liar. Though the prosecutor asserted a Soviet inspiration to the plot to kill the pope, the more cautious Judge Martella avoided making that charge.

Martella did, of course, charge three Bulgarians with complicity in the crime, and one can fairly ask why this cautious, highly regarded investigator would do that if he didn't think he had a good case.

There is a possible answer to that question. Swayed by Agca's testimony, Martella decided in November 1982 to arrest the only Bulgarian within reach, Antonov. Under Italian law, Martella could hold Antonov without charges, as he did for two years. Subsequently, Agca changed much of his story repeatedly, but Martella held Antonov in prison or under house arrest. Antonov's Italian lawyers claim that Martella is simply trying to justify his holding of Antonov for two years by turning his admittedly circumstantial case over to a Roman court for a final decision.

Rome's court of assizes will get the case sometime next year. Two judges and six lay jurors will hear the evidence and render a decision by majority vote. Lawyers for the defendants, particularly Antonov, will try to undermine Agca's credibility; the prosecution will presumably try to sustain it. Surely we should at least wait for the outcome of the trial before deciding ourselves whether there was a "Bulgarian connection."