Oliver Gasch, the long-serving U.S. District Court judge whose dozens of high-profile cases included the criminal trial of Senate Secretary Bobby Baker, and who ruled in another case that President Jimmy Carter had violated the U.S. Constitution, died yesterday after heart surgery at Georgetown University Hospital. He was 93.

Gasch was appointed to the court by President Lyndon B. Johnson in 1965. He served for 16 years and then went into semi-retirement, remaining on the bench for 14 more years as a senior judge.

His decisions cut a broad swath across the workings of the city, its businesses and citizens and affected the day-to-day operations of the federal government. They included finding that Georgetown burial sites for African Americans should be preserved as historical sites, allowing homeless shelters near the Watergate apartments, and opening the way for the launching of nuclear payload-bearing space shuttles.

In between, there were hundreds of civil and criminal cases involving the famous and powerful as well as the obscure and penniless. The District Court in Washington is the venue for cases involving federal agencies, and issues of national security and other government matters often are heard by its judges.

During his 30 years on the bench, Gasch was known in legal circles for his long working hours and prolific but concise judicial decisions.

In 1969, four years after Johnson appointed him to the court, he was embroiled in a much publicized income tax evasion case against Baker, who had been a top aide to Johnson in the Senate. Baker was accused of peddling influence while serving in the Senate, and the trial drew national attention. Gasch sentenced Baker to one to three years in prison. It was one of the few trial losses suffered by Baker's renowned defense attorney, Edward Bennett Williams.

In the case against President Carter, Gasch determined that he had violated the Constitution when he unilaterally terminated the mutual defense treaty between the United States and Taiwan. That decision was reversed by the federal appeals court.

Gasch presided over the trial of Rep. Charles C. Diggs Jr. (D-Mich.), who was convicted in 1978 of mail fraud and other charges for illegally diverting more than $60,000 of his congressional payroll for his own use. Diggs was sentenced to up to three years in prison.

Gasch also handled the trial of Rep. Daniel J. Flood (D-Pa.), who was indicted on bribery and conspiracy charges in connection with his role as chairman of a House Appropriations subcommittee. Flood pleaded guilty to mail fraud and tax evasion.

In 1973, at a time when President Richard Nixon was testing his power to cut or kill federal programs, Gasch ruled that the Environmental Protection Agency had to allocate $6 billion in water pollution control grant funds that Nixon had ordered withheld.

In 1979, Gasch opened the way for Pope John Paul II to perform Mass on the Mall after atheist activist Madalyn Murray O'Hair tried to block it on constitutional grounds. Gasch said the National Park Service had not violated its regulations because the Mass was open to people of all faiths.

Gasch was a lifelong resident of Washington and a graduate of Western High School. He received his undergraduate degree from Princeton University, working his way through school by running a picture-framing business.

He later received a law degree from George Washington University. He attended classes at night while working for the city bus company that was a predecessor of Metro. As a judge many years later, he helped persuade the university to retain the night division after plans were announced to discontinue it.

Gasch was named to the D.C. corporation counsel's office in 1937 and was later chief of the trial section.

He served in the Army judge advocate general's office in the Philippines during World War II, and he continued after the war as a lieutenant in the reserve.

Active in Republican politics, he was named principal assistant U.S. attorney for the District and then was U.S. attorney from 1956 to 1961.

He was in private practice and served as president of the D.C. Bar Association before being named to District Court.

Among his trials as a senior judge was the libel suit brought by Mobil Corp. President William P. Tavoulareas against The Washington Post. Tavoulareas said his son had been slandered in a Post article that said he had been "set up" in a shipping business.

A jury returned a $2 million verdict in 1982 in favor of the Tavoulareases. But the next year, Gasch reversed the verdict, saying that while the article fell "short of being a model of fair, unbiased, investigative journalism," there was "no evidence . . . to show that it contained knowing lies or statements made in reckless disregard of the truth." That decision was reversed on first appeal but was ultimately upheld.

Gasch served on a special three-judge panel that heard a challenge of the constitutionality of the Gramm-Rudman Deficit Reduction Act. The panel ruled, and the Supreme Court later affirmed, that the act violated the separation of powers doctrine of the Constitution.

In 1989, Gasch denied a Northern Virginia homeless group's request that a federal parking lot overlooking the Pentagon be turned over to it for housing. But that same year, he also found that the Department of Housing and Urban Development failed to take the needs of the homeless into account by simply auctioning off foreclosed single-family homes to the highest bidder.

In the early 1990s, he rejected petitions from anti-nuclear groups seeking to block launchings of space vehicles with radioactive payloads.

In 1991, in a controversial decision that preceded the "don't ask, don't tell" policies of the military, Gasch upheld the right of the U.S. Naval Academy to expel a midshipman nine months short of graduation because he had acknowledged to a classmate that he was gay. Gasch said the ruling was needed in part to help prevent the spread of AIDS in the armed forces.

Outside the court, Gasch was a chancellor of the Episcopal Diocese of Washington and a vestryman at St. Alban's Episcopal Church. He was a director of the Landon School for Boys, president of the Reserve Officers Association of D.C. and a member of the Military Order of the Caribou, Chevy Chase Club and University Club. He also had been general counsel of the Interstate Commission on the Potomac River Basin and of the Boys Club of Washington.

Survivors include his wife of 56 years, Sylvia Meyer Gasch, of Washington, the retired principal harpist and soloist of the National Symphony Orchestra; and a son, Michael Gasch of Bethesda.

CAPTION: JUDGE OLIVER GASCH

CAPTION: Judge Oliver Gasch heard cases that affected District residents and the federal government.