The headline on a report Monday about two major cases this year involving the FBI's Los Angeles bureau incorrectly referred to "acquittals." One case ended in a mistrial.

The recent mistrial in the Richard W. Miller spy trial was a milestone: It was the first time the U.S. government failed to get a conviction in an espionage case.

Last year, celebrity automaker John Z. DeLorean was acquitted on drug charges by a jury in the same federal courthouse where on Nov. 6 Miller's jurors, after a three-month trial and 14 days of deliberations, announced themselves "hopelessly deadlocked."

In both cases, guilty verdicts had seemed sure bets. In both cases, FBI investigators had their quarry on tape: Miller's conversations with Soviet emigre Svetlana Ogorodnikova; DeLorean poking at a bundle of cocaine that he pronounced "better than gold." And in both cases, alleged co-conspirators had already pled guilty.

But in both cases, the government came up empty handed. So now some law enforcement experts are speculating that something may be wrong at the FBI's Los Angeles office -- which not only played a major role in both investigations but had assigned Miller to the foreign counterintelligence squad.

In the DeLorean case, the cocaine in the hotel room where he was arrested had been brought there by government agents. And the prosecution's star witness, an informer who reportedly had boasted that he would "get" DeLorean for the government, was a convicted drug smuggler and admitted perjurer. The jury foreman, a former law enforcement officer, said after the acquittal that he jury felt the verdict "would indicate to the government that they should reevaluate their investigative techniques."

In the Miller case, trial testimony described the defendant as a career-long bumbler. U.S. Attorney Robert C. Bonner, who prosecuted, said in his closing argument that "it's only natural to ask" whether Miller should have been fired from the Federal Bureau of Investigation long before his arrest. But he added: "That's not the way it works in government or the FBI. Maybe that's the way it should work."

Other testimony at the trial established that, although his career had been riddled with problems, Miller often received an "excellent" rating. Testimony also showed that 90 percent of the bureau's agents get that rating each year.

Neil Welch, a former assistant director who served 29 years with the FBI, said the bureau now has "a lack of willingness to fire people . . . . You literally can't get rid of anybody. The only thing you can do is transfer them around." Welch said it wasn't always so: the late FBI Director J. Edgar Hoover "would have fired Miller, and half the agents in California."

Many defense attorneys say that the problem is much broader than one FBI office, that it goes beyond a single agency.

Howard Weitzman and Donald Re, who defended DeLorean and have since dissolved their partnership, are two of the defense attorneys who say they think that problem is rooted in Washington. "We have an arrogant administration that brings with it the attitude, 'We can do no wrong,' " Weitzman said. "The public perceives that, juries perceive it. And they don't like it."

But there is also criticism aimed specifically at the FBI's Los Angeles office. Welch said one of many questions raised by the Miller case is: "Why was he, an incompetent guy who should have been dismissed, put in a sensitive role?"

There have been charges, both by Miller's attorneys and by an FBI agent who filed a complaint with the Equal Employment Opportunity Commission, that Richard T. Bretzing, the agent in charge of the Los Angeles office, gives special treatment to Mormons. Bretzing is a bishop in the Mormon church; Miller is an excommunicated Mormon. Testifying at Miller's trial, Bretzing denied that religion played any role in his duties.

Tony Genakos, an FBI spokesman in Washington, noted that testimony at Miller's trial had established that the severest disciplinary actions against Miller -- suspensions without pay -- were taken by Bretzing and and P. Bryce Christensen, Miller's former supervisor on the foreign counterintelligence squad and now an assistant agent in charge of the Los Angeles office.

Genakos said reports that Bretzing would be removed as head of the Los Angeles field office are "baseless rumors." Genakos pointed to the office's "thousands and thousands" of successful cases and added, "It's unfair to take two cases and say, hey, there's something wrong with the FBI."

Fred Reagan, an FBI spokesman in Los Angeles, said that in terms of arrests and convictions, "We are the flagship of the FBI." Reagan said the criticisms are "a mirage . . . value judgments. That something is wrong, that morale is bad. These are things I don't see."

Weitzman and Re both said they think that the prospect of publicity sometimes skews the judgment of law enforcement officials. "I truthfully think they rushed into [the Miller case] to save some face in the wake of the DeLorean case," Weitzman said.

Re, who was not involved in the Miller case, criticized the FBI's investigation: "They take the tack, immediately, that he is a sophisticated spy, not a bungler . . . . You're supposed to go out and investigate for the truth, not make things come out the way you've already decided they're going to come out."

Genakos responded: "That sounds as though they're saying we frame people . . . that's attributing some sort of nefarious motive that just isn't there . . . . I think our record shows otherwise."