R. Kenneth Mundy, one of the District's most effective trial lawyers, has never laid claims to preeminence in the library. More comfortable with juries than with abstract legal research, the mayor's lead attorney has just finished eight weeks of battle on the turf where his trial skills matter least.

Like it or not, as Mundy observed wryly last week, Marion Barry's defense required "a flotilla of motions" before trial. With colleague Robert W. Mance, Mundy launched 16 of them -- seeking dismissal of charges, suppression of evidence and a variety of tactical advantages for the mayor's coming trial.

Yesterday the last of the flotilla sank without a trace in Judge Thomas Penfield Jackson's federal courtroom. Experienced criminal lawyers said the defeats for the mayor, though expected, were made inevitable by a lackluster performance from the defense.

In effect, the experts said, the mayor is betting everything on Mundy's demonstrated magic with D.C. juries. But the decision to "go through the motions," as one lawyer put it, instead of fighting them aggressively, appears to have cost the Barry defense important opportunities.

"Ken's not a great legal theorist, and that's not what he was hired for," said Frederick D. Cooke Jr., a former D.C. corporation counsel under Barry. "He has basically focused his effort on persuading the potential jury panel, and ultimately those 12 or 14 or 16 people in the box, that this isn't a crime worth convicting his client about."

A typical exchange last Friday, when most of the motions were argued, began as Mance tried to persuade the judge that the case against his client should be dismissed because of "prosecutorial vindictiveness."

"Case law doesn't help you very much," Jackson observed, smiling slightly.

"Case law, quite candidly, does not give us a lot of support, because it's against us in terms of what we have to show," Mance allowed, and indeed he did not seem fully familiar with the cases. The judge, he urged, should grant the motion anyway. Jackson was unimpressed.

Impressing the judge, however, has not been the principal goal of the defense. Mundy and Mance have aimed from the beginning at the public, and, by extension, at the jurors.

In many ways the most important pretrial battle has been one of public relations. For all the sparseness of their legal reasoning, the motions by Mundy and Mance have consistently made news in local newspapers and television broadcasts with their message: that the prosecution, not the mayor, should be put on trial.

Sources close to U.S. Attorney Jay B. Stephens said Stephens, too, regards the battle for public approval as fundamental. Government briefs filed in reply to Barry's motions have been full of quotable jabs at the mayor's character and candor.

"No one forced the defendant to go to the hotel room at the Vista Hotel," said one reply. " . . . No one forced him to smoke the crack. To the contrary, he deliberately engaged in this criminal conduct as he had on scores of other similar occasions."

Prosecutors, in fact, have sometimes been disappointed with the public impact of their arguments, even as they stacked up victories in the courtroom. Sources said Stephens and criminal section chief H. Marshall Jarrett were amazed and frustrated when they attracted little media interest with a revelation that Barry -- contrary to his previous public statements -- had asserted his Fifth Amendment privilege against self-incrimination in grand jury testimony in early 1989.

But Mundy's success as a publicist has had corresponding disadvantages in the case. Experts said a more substantive pretrial defense could have:

Forced the government to reveal more of its evidence in advance. When prosecutors have to grapple with an argument, lawyers said, they often give up previously undisclosed details of their case. Mundy did secure important new disclosures about the government's case, but some lawyers thought he could have accomplished more.

Built a reservoir of credit with the judge. "As long as your motions aren't completely frivolous," said lawyer Henry W. Asbill, "you set yourself up for an argument to the judge, 'Hey judge, you've denied my last 100 motions. Go my way just once to prove that you're fair.' If you time that right you can get what you need to win -- whether it's a closing instruction or a little extra leeway with the jury."

"Frozen" important elements of the government's case. Everything prosecutors say in advance offers an opportunity for the defense to find contradictions with the evidence that emerges at trial.

Built stronger grounds for a successful appeal in the event of conviction. Trial judges are not known for making new law, but appeals courts often do. Novel, creative arguments -- about limits on prosecutorial conduct, for example -- usually have to be offered at trial if the appeals court is to consider them afterward.

Cooke, who admits to membership in the "reams-of-paper, kill-forests" school of litigation, said he would have "spent a lot of time trying to knock {the case} out procedurally if I could.

"But if I had the gift that Ken does on my feet in the courtroom," Cooke said, "I'd feel a lot better, because I would know . . . I still had a real big gun to shoot."