Once, while jurors in a darkened courtroom watched one of his clients' films before deciding whether it was obscene, he fell asleep at the defense lawyer's table, snoring loudly, to demonstrate that the film really wasn't very exciting.In another obscenity trial, he brought the jurors a big bag of popcorn for the film showing.

He convinced the judge in one case that a book depicting a woman's sexual escapades with various animals had some redeeming social value and therefore was not obscene.

But for another client, an adult bookstore operator sued by a pornography distributor for failing to pay for books that had been ordered, he argued that the books were obscene, and therefore illegal, so the bookstore operator should not be made to pay for them. He lost that case.

For the past 20 years, Stanley Martin Dietz has made a respectable living and substantial legal reputation by keeping local purveyors of pornography out of jail and in business. He has helped them open adult bookstores and movie houses, fight obscenity prosecutions and settle their occasional internecine disputes.

Dietz has argued two test cases on pornography before the U.S. Supreme Court that established new obscenity standards. And he fought a pioneering, although losing battle three years ago, to permit the showing of the film "Deep Throat" at the Mark II Theater in downtown Washington. Times have since changed, in part because of Dietz's efforts in court, so that movie and books far more libertine than "Deep Throat" are widely available here.

The tough-talking lawyer, with the eyes and quarter-moon moustache, takes quite seriously his job of handling the legal affairs of most entrepreneurs in the pornography business here.

His sometimes zany courtroom antics are an integral of a serious defense strategy, carefully calculated to win jurors over to his contention that obscenity, like beauty, is in the eye of the beholder. When he defended one adult bookstore owner charged with selling obscene magazines, for example, Dietz brought to court large pictures of naked men to prove "the longer you look at a sexual scene, the more boring it gets."

Dietz says that movies like "Deep Throat" do indeed put him to sleep and he calls adult books and magazines "garbage." So why does he defend them so vigorously?

Money? "Sometimes I have good years, sometimes bad," he said. "One year I'll make $80,000 (net before taxes). Last year I made $40,000 (net) . . . You couldn't convince the police or the FBI that I have no proprietary interests in the bookstores I defend. But the truth is I don't."

Principle? "There are constitutional issues involved in these cases," he argued. "We're talking about the right to say your piece. . . Freedom of speech, that's what it boils down to."

Dietz's unique practice also has given him something else desired by any lawyer -- his own special niche in Washington's cluttered legal heirarchy.

In his vested suits, patent leather shoes and flashy ties, Dietz is a familiar figure in courthouses here. Secretaries recognize him with warm smiles. He is careful to remember their first names, too, and to give them rogueish, head-to-toe, once-over looks only when their backs are turned.

Once a grocery delivery boy and a soda jerk back in Brooklyn, the 50-year-old lawyer now drives a 1971 Lincoln, wears custom-made coats and a black fedora from Dobbs of Fifth Avenue.

At Paul Young's and Duke Zeibert's, waiters greet "Mr. Dietz" with a warm handshake and show him to his usual table. He rewards them in turn with $30 tips, playing the role of the successful Washington attorney.

His tough guy manner, earthy language and the toothpick he dangles from his mouth are all New York. Seated on a swivel chair in front of an American flag and behind mounds of papers on the desk in his Vermont Avenue NW office, he conversed with a client who had called him on the phone in gruff Brooklynese: "I hear you're having problems with wife No. 2. . . Did you catch her (with) somebody elsez. . . Well that's not adultery just because she's seeing some other guy. . . all right, all right, scratch up about a hundred-fifty and come on down."

In his private life, Dietz actually is something of a straight arrow. He does not drink or smoke. He generally works from 9 a.m. to 9 p.m. and spends most of his weekends either working or on the golf course.

Dietz keeps 13 pictures of his daughters -- ages 15 and 19 -- in his Washington office. "He's a very good father. . . he's always worried about getting home to dinner," said Terry Roberts, who worked as Dietz's law clerk until last month, and was his caddy as a boy.

Following a 1976 divorce, (after which his oldest daughter left home for California), Dietz now lives in a $56,000 townhouse in Montgomery Village, which doubles as his Maryland office, with his 15-year-old daughter and his mother-in-law, 68. He calls his wife's mother "Grandma."

Some of his vigor with which Dietz argues cases in court could be traced to his physical stamina, pushed to the limit in 1956 when he suffered 18 broken bones, including both legs and arms and his jaw, in a car crash in Florida. Diez's mother, who was driving, ran into a train, and both she and his father were killed.

Dietz's early ambition in life was to start a liquor business or hotel in Florida with a buddy from Flatbush. After a stint in the Navy, where he served as an aviation radio man, Dietz came to Washington to study business administration at George Washington University.

"There were so many times when someone would ask the professor a question and he would say, 'Well, you'll just have to ask your lawyer about that.' So I had some GI benefits left and figured I'd better go to law school." And he did, graduating from a two-year accelerated program at George Washington.

Dietz said he never intended to practice law after passing the bar, but an encounter almost three decades ago with a D.C. policeman in a taxi changed his mind. "I got into this taxi with this cop who started telling me and my buddy how he'd shot this 'nigger' in an alley. . . I thought to myself, this is how they administer justice, I'm going to stay here (in Washington) for six months and defend all the Negroes that I can. . . It's now 26 years later."

It was just as much by coincidence that Dietz began defending pornography defendants.

During the 1950s, Dietz represented several homosexual men who charged that they had been brutalized by D.C. police. Herman Womack, a local philosophy professor and a homosexual, hired Dietz as his attorney when he began encountering difficulties with the Post Office for selling homosexual magazines through the mail.

When Womack's company MAN-ual Enterprises, sued the postmaster general, Dietz took the case to the U.S. Supreme Court. In a landmark decision, the high court ruled that neither the Postmaster General, nor any U.S. agency except a federal court, had the authority to determine what is obscene.

In addition, the court agreed with Dietz's argument that Womacks homosexual magazines, featuring men in tight-fitting underpants and naked little boys, were not "patently offensive" to Womack's male subscribers, and therefore not obscene.

Another case Dietz later argued before the Supreme Court helped establish two of the tests by which courts determine what is obscene: Would the materials in question be considered obscene by the standards of the community at large? And do the materials have any social redeeming value?

"Take a magazine like Playboy. That is considered to have normal erotic appeal. . . But that doesn't make the magazine obscene, because it's not obscene to the community at large." What is comes down to, insisted Dietz, is that pornography is "a matter of taste."

According to Dietz, there are three types of pornographic materials that "a jury in this area would not tolerate."

Material dealing with children

Scenes showing physical abuse (whippings, blood, bruises)

Depictions of sex acts with animals.

Dietz says he advises his clients in the pornography business not to sell books or films that contain any of those three elements.

The bottom line of pornography in court, says Dietz, is whether or not the prosecution can prove that the alleged pornography appeals to a person's "prurient instinct" and is "patently offensive" to viewers.

Next: Washington's original pornographer.