The case is sordid. It involves clandestine sex. There are allegations of violence and perjury. And in the middle of it all is a lawyer named Billy Martin, who is riding a dirty whirlwind yet never seems to soil his button-down Polo shirt.

It's not the case of Chandra or Monica -- to shorthand just two of the scandals featuring Martin as a key player. No, today we're watching Martin in his natural habitat, the hushed, cool confines of D.C. Superior Court.

Attorney William R. Martin, for the defense, is the very model of a smooth and seasoned criminal litigator. His client, unfortunately, is the very model of a reckless student athlete.

Attila Cosby, 6 feet 10, a suspended player on George Washington University's basketball team, is being tried on charges of abusing an alleged prostitute. To wit: forcing her to perform oral sex at gunpoint and violating her with a broomstick. Cosby, 23, says he picked up the woman in May 2000 during a spell of "bad judgment -- I was totally not thinking right."

She admits she was high on crack but insists she wasn't turning tricks that night. Cosby denies threatening her in any way.

"I'm a very kindhearted guy," he testifies under cross-examination. Warily, Martin watches from the defense table as his client enters the cross hairs of the prosecutors.

Yes, Crosby allows, he's always been fond of guns, ever since childhood. But, no, he would never pack a revolver, as is alleged.

Revolvers are just not safe, he says. Cosby prefers semiautomatic handguns, such as the Ruger and the Glock he legally owned at the time of the incident in his GWU dorm room. Cosby, who earlier testified that he'd never even "used" a gun before, then volunteers to the judge how he once accidentally shot himself in the leg with a revolver when he was 16 and . . .

"The cat is out of the bag," Martin says, on his feet now and trying to minimize the damage. Cosby has not only contradicted his earlier testimony but made his juvenile record fair game. The big man -- he plays center and power forward -- has a big mouth. He shot himself and winged his defense attorney, too.

"I'm getting clobbered, my head is spinning," the usually unflappable Martin grumbles outside the courthouse. Reporters are milling around for quotes on the latest development on missing intern Chandra Levy. Martin represents her mother and father: He helped blast the case into the media ionosphere last week by accusing Rep. Gary Condit of lying about his affair with Levy and challenging him to take a polygraph examination.

But right now Martin is more worried about Cosby. Last year a judge dismissed a felony rape charge against the athlete for lack of evidence. But prosecutors refiled nine misdemeanor counts that could bring more than four years in prison.

To cynics, Martin may come off as another media-savvy legal mouthpiece whose specialties include keeping prominent athletes out of jail. Among his clients: boxing champ Riddick Bowe, who got probation after abducting his wife and kids in North Carolina and court-ordered treatment for another incident in which he allegedly assaulted other family members in Maryland; then-Washington Wizards star Rod Strickland (probation for his first DUI arrest); then-Wizard Juwan Howard (sexual assault case dismissed by the grand jury); and Philadelphia 76er Allen Iverson (assault allegations dismissed by the grand jury). But Martin enjoys a spotless reputation among lawyers and clients for his work in the gritty legal trenches, as well as in the corridors of corporate power. He's the new go-to guy in D.C.

"You're everywhere lately," Diane Lepley, a local defense attorney, says when she sees Martin pausing for an iced latte near the courthouse. She pumps his hand.

Is there such a thing as too much exposure for a lawyer?

"For some of us, maybe," says Lepley. "But not for this guy."

Cochran Kudos "I can't hide in this city," says Martin, 51, a modest smile crossing his impish face. He can't hide his delight, either. Humility is hard to maintain as people constantly wave their congratulations from the sidewalk and stroll over to bask in his celebrity:

"How you doing, man."

"Saw you on TV."

"You're working hard. When I see you on TV I pray."

A minister, a U.S. marshal, a cop, a federal prosecutor, folks he doesn't even recognize: nearly all of the well-wishers are African Americans. Billy Martin makes them proud.

"Two thumbs up. He is a real fine lawyer. Very, very thorough," says Johnnie Cochran, who once could have trademarked the term "Famous Defense Attorney" but doesn't mind ceding territory to Martin, a good friend.

"After I saw him on 'Good Morning America' I called Billy and said, 'You make me proud the way you handle yourself. You're controlling the agenda here, and that's what a good lawyer does, controls the agenda.' "

But unlike other power lawyers, "Billy doesn't have an intimidating manner," says one of his civil-practice clients, former Georgetown University basketball coach John Thompson. "He mixes a common touch and friendliness with his competence and his ability."

More than a decade ago, Thompson began advising sports franchises (the Pittsburgh Penguins and Pirates) as well as athletes (he worked for the NFL Players Association). Thompson hooked up Martin on some headline-making sports cases when he recommended him highly to lawyer-agent David Falk, who represents several athletic superstars. Martin, says Thompson, knows his way around Washington "at every level, from the lowest of street levels to the highest of sophistication."

Martin grew up outside Pittsburgh, the son of a steelworker. His mother raised eight children and also worked as a caterer and domestic. Today Martin charges $400 an hour, but like other high-buck defense lawyers, he first toiled as a government prosecutor. That part of his career lasted 15 years.

He attended Howard University and the University of Cincinnati College of Law. As executive assistant U.S. attorney in the District, he learned the importance of solid investigation: He helped prosecute then-Mayor Marion Barry on drug charges as well as the notorious crack ring leader, Rayful Edmund III.

Working in the 1980s for the federal Organized Crime Strike Force in San Francisco, Martin handled complex cases involving the mob and the Teamsters. After crossing over to the defense bar in 1990, he kept many friends on the law-enforcement side, and maintained their respect.

"I'm honored to be in his presence," says Charles W. Cobb, an assistant U.S. attorney here who knows Martin well. But the go-to guy demurs. "I'm just one of the people's lawyers," Martin says.

The Double-Edged Sword Martin first flared to national fame in 1998 when he was hired by Monica Lewinsky's mother, Marcia Lewis. He handled her grueling, theatrical grand jury appearances. He also urged the family to fire William Ginsburg, the showboating California malpractice lawyer, and get more experienced local counsel, which Lewinsky did.

Martin developed another sui generis skill during that last mad season of daily intern-sex headlines: He became an expert at eluding media stakeouts. His secret? "Switch cars" and decoy limos, he says, recalling how he got Lewinsky and her mother around town undetected.

After another long day in the Attila Cosby trial, Martin exits the courthouse and narrows his eyes at a TV truck in the distance. No need to dodge -- it's a friendly reporter, Channel 4's Jackie Bensen, prowling the sidewalk in a chic camouflage-pattern top. These days Martin seems to have a lot of journalistic friends, and he even married one of them: ABC correspondent Michel Martin, 42, formerly a reporter for the Wall Street Journal and The Washington Post.

Michel Martin says the relationship got rolling after Billy volunteered to carry her handbag and shawl during the 1996 Radio and TV Correspondents' Dinner -- she was weighed down by the bulky crystal award she had won. He drove her home and she invited him in for coffee. "Has your status changed?" he asked, diplomatically referring to her availability. She had just gone through a divorce, so the answer was yes. They wed in June 2000 and live in the District. (Martin has two grown daughters from a previous marriage.)

During the Lewinsky scandal, Billy Martin wasn't nearly so visible or voluble. This newspaper dubbed him "low-profile." In August 1998, a Wall Street Journal reporter profiled him under the headline, "Little-Known Adviser Becomes Key Lewinsky Strategist." The story's author, Michael Frisby, eventually went into PR and now serves as Martin's spokesman.

Instinctively, Martin straightens his tie and buttons the jacket of his sharp (but still off-the-rack) suit before he does two minutes for Channel 4. Bensen seeks his response to reports that Condit wants to limit the scope of a lie-detector test.

The Levy family, Martin says, wants "a full and complete session. . . . We want to know full answers." Afterward, for the benefit of the cameraman, the lawyer poses for a two-shot with Bensen and does a walk-off shot across Indiana Avenue NW.

But cooperating with the media "is a double-edged sword," Martin says later. "Once you start talking to the press, you have to keep talking."

How did he get the job representing the Levys? He won't dish all the specifics, but corrects the impression that it might have been because of his role advising the Lewinsky family.

Of course the saga of President Clinton's dalliances with Lewinsky shares some similarities with Condit's trysts with Levy. Long-married politicians in their fifties with steely haircuts, looking more and more dyspeptic on camera as the stonewall crumbles. "You have promises of a married man to a young girl: 'If I weren't married, you'd be foremost in my life,' " Martin notes. "You have a distressed family."

It turns out that Martin's name was passed to the Levys by a Bay Area lawyer from his Strike Force days. His law-enforcement background got him hired: "They wanted somebody who could actually get the respect of the [D.C.] police department," he says.

Martin drilled down on the case as if it were a homicide, though he says his only mission is "to find out what happened to Chandra" by conducting "a complete and independent investigation." He deployed two retired D.C. homicide detectives as full-time private eyes.

Levy's parents, Robert and Susan, felt police were not being responsive enough, Martin says. The family suspected Condit was withholding information about his affair with Chandra. They were, understandably, "very demanding" in their quest for action, Martin says. But the police, also understandably, didn't want to disclose information about the probe.

Enter Martin to "bridge the gap," as he put it. To wield a truncheon of persuasion via the media, while wearing a velvet glove. And yesterday, on "Meet the Press," Martin kept the pressure on, saying he wasn't impressed by the lie-detector test Condit passed ("The way this thing was set up by his attorney is slippery, it's slick"). He advanced the theory that Chandra Levy was lured from her apartment by someone she knew.

"He energized this investigation. They weren't going anywhere until he got in there," says Cochran. "He energized the D.C. police department: Now they want DNA samples and they're carrying out boxes from Condit's apartment."

Doubt and Reassurance DNA evidence, sordid tales of multiple affairs, somebody's lying: Sex stories, it seems, are always the same. The one involving the California congressman may keep Martin on the national news, but back in Superior Court, it's been tough going for the defense.

During his closing argument to the judge -- no jury in this trial -- Martin methodically rebuts what he calls the prosecution's "fantasy theory" of Attila Cosby as a demented, perverted attacker. The attorney describes a naive athlete "with a young man's swagger and macho presence," desiring quick sexual release because his girlfriend was nine months pregnant at the time.

Cosby was weak-minded, and he was tempted by this stoned prostitute, "a woman possessed of crack cocaine," says Martin. "She stopped my client, she flagged him down."

When she wasn't paid enough for her services, she concocted the story, Martin argues. He also strongly appeals to that faithful friend of the innocent and guilty alike: reasonable doubt.

Outside the courtroom, the goliath is comforted by his girlfriend. She is trim, attractive, tattooed. Cosby looms two feet above her.

The judge will decide his fate Tuesday morning. "We got a shot at this -- don't give up, okay?" Martin is reassuring his client. "Hang in there."

Later, finishing his beloved Starbucks latte, Martin concedes that representing athletes in their scrapes with guns, women, dope and booze can become tiresome. "It gets repetitive," he says. The one sport he expresses a serious passion for is the one he plays, golf, which is usually a more gentlemanly pursuit.

A young man wanders by, inquiring about a Starbucks job while nonchalantly dragging on a blunt -- a cigar packed with marijuana. Martin wrinkles his nose. A wind kicks up, blowing debris around the outdoor patio. A cop cruiser roars by.

A small whirlwind snatches up some plastic takeout cups. Martin's coffee topples but doesn't spill on his suit.

"I'll get that," he says, bending to the ground to clean up. Then he disposes of the trash.

History repeats itself: Billy Martin, who represents the family of missing intern Chandra Levy, not so long ago advised the family of another Washington intern surrounded by controversy, Monica Lewinsky."I can't hide in this city," Martin jokes, but he acquired the skill of eluding media stakeouts during the Lewinsky case.