Law enforcement officials yesterday attempted to distance themselves from an ill-fated bribery investigation of then-D.C. Mayor Marion Barry, but the lead FBI agent said he had support from top supervisors and kept them fully briefed throughout the inquiry.

"I don't think anyone believes that just being an agent, I would be able to run or conduct an investigation of this nature on my own," said William H. Spivey Jr., a 16-year FBI veteran who was in the public integrity section.

In a planned sting operation last year, authorities hoped to catch Barry on videotape taking money from someone seeking a D.C. government job. FBI officials declined to comment about details of the investigation. The U.S. attorney's office said it never approved the plan, which was not carried out. One source familiar with the case said some officials in the U.S. attorney's office viewed Spivey as a "loose cannon" too eager to act.

Without discussing specifics, the FBI acknowledged yesterday that a single agent acting on his own could not have initiated the Barry investigation. FBI spokeswoman Susan Lloyd said that the FBI typically requires "levels of authorization. In general, decisions about investigations are made by a team of individuals--agents, their supervisors and prosecutors."

Spivey and top supervisors at the FBI's Washington field office believed a sting operation had the potential to capture the four-term mayor on videotape accepting a bribe, law enforcement sources said. But the U.S. attorney's office was skeptical and demanded a stronger foundation, the sources said. The discussions were described as part of the natural give-and-take that takes place in criminal investigations, with one side pushing for action and the other for more information. Usually such discussions remain private.

But details emerged on Thursday, when a federal judge unsealed transcripts of previously secret hearings in the case of Yong H. Ahn, a former D.C. police lieutenant who was arrested in February 1998 on charges of taking bribes from operators of illegal massage parlors. Ahn and his wife, Azita, agreed to aid the FBI and D.C. police department's internal affairs unit in an investigation last year that ultimately targeted Barry.

Barry, who did not seek reelection last year, responded to the revelations with outrage. Despite numerous investigations dating to his first term in office, he was convicted only once, of a misdemeanor drug charge stemming from his arrest in a 1990 sting at the Vista Hotel. Barry said he would never accept money for jobs.

His wife, Cora Masters Barry, also condemned the law enforcement tactics yesterday. "After a while, you just get tired of being harassed," she said. "This is not a new phenomenon. People have been harassed by the FBI forever in an insane, irrational theme about this man."

According to the transcripts, authorities hoped to set up a meeting in Northern Virginia with Barry in which Azita Ahn would offer money in return for a D.C. government job. Spivey testified at a hearing that the operation was scheduled for April 1998 when news leaked about Ahn's arrest, derailing the investigation.

By targeting Barry in Virginia, prosecutors could have brought charges in Alexandria instead of in the District, where a jury in the 1990 case had been unable to reach a verdict in 12 of 14 counts, in the end convicting him of only one misdemeanor count of drug possession. But other sources familiar with the matter said the sting never came close to taking place. Prosecutors were reluctant to pursue anything but "a clean and straightforward" case, said one law enforcement source involved in the discussions, speaking on condition of anonymity.

The source said a team of prosecutors doubted Barry "would bite" and didn't believe the sting had a chance of success. The source said the basis for believing Barry might take a bribe was murky, and prosecutors feared that pursuing Barry on shaky grounds would appear vengeful.

Instead, the source said, prosecutors wanted Ahn to focus his efforts on allegations of corruption in the D.C. Department of Consumer and Regulatory Affairs, the city's licensing arm. Ahn wore a hidden recording device on at least three occasions, and his efforts eventually led to a guilty plea from a licensing official whose case remains under seal.

Spivey declined to say yesterday how the Barry investigation came about. Others said Ahn, who was caught on videotape taking money from two massage parlor operators, offered information about Barry and others in hopes of getting a plea bargain and more lenient sentence. Ahn wound up with a four-month term at his sentencing on Tuesday.

After the Barry plans collapsed, Ahn and his lawyer attempted to withdraw the guilty plea and accused law enforcement officials of leaking news about Ahn's arrest. The transcripts released Thursday were from hearings in October 1998. At the conclusion, U.S. District Judge Thomas F. Hogan did not permit Ahn to withdraw his plea.

Spivey, called as a defense witness, testified that the FBI helped prepare a phony resume for Azita Ahn, that a meeting with Barry was going to be planned through an intermediary, and that plans called for the entire exchange to be secretly videotaped. But, he said, "The day before we were going to pass the resume and the money, the story broke in the news media."

Spivey's FBI career was put on hold right after the hearing. He was placed on administrative leave after a series of allegations stemming from unrelated workplace episodes dating to 1993.

According to court documents unsealed this week, the FBI was investigating a 1993 incident in which Spivey allegedly took a friend on an unauthorized ride on an FBI aircraft, a 1996 incident in which Spivey allegedly sought to intercede on behalf of a "source" accused of bank fraud, and a bizarre series of events involving a corruption case against another D.C. police officer.

Spivey was the lead agent in the case against Michael Cencich, who pleaded guilty in May 1998 to demanding money from people who run houses of prostitution. As part of a plea bargain, Cencich agreed to work with Spivey and the FBI in a broader investigation of police corruption.

Instead of pursuing leads, Cencich claimed, Spivey sent nude photographs of himself via the Internet and numerous e-mail messages depicting sex acts to Cencich's wife, suggesting that if she agreed to a relationship with him, it would help her husband. Cencich turned over copies of the materials to the FBI in August 1998, triggering an investigation into Spivey.

Cencich, who hoped to get a more lenient sentence by leading the FBI to other crooked police officers, got a break in his case. A judge sentenced Cencich last April to a 15-month term, citing his cooperation.

Spivey's attorney, William B. Moffitt, contended yesterday that Cencich manufactured the allegations against Spivey and the agent did nothing wrong in the other instances under review. Moffitt said FBI officials had been determined to retaliate against Spivey for years because he was a leader in a class-action lawsuit alleging racial discrimination.

CAPTION: Former mayor Marion Barry says he would never have sold jobs.