William H. Oliver left nothing to chance.

Last week, less than a month before his 39th birthday, Oliver, a thin, small-framed man with short blond hair and a bushy mushtache, prepared his tiny Alexandria apartment for his last rites.

He meticulously taped his door airtight. He slipped his chain lock into place.

He went into the kitchen, where he pulled a plastic garbage bag over his head, taped it tightly around his neck and connected it to his gas stove.

He then turned on the stove and sat down for the last time.

He had made no telephone calls and he left no suicide notes.

Oliver was a homosexual, but he kept it secret, telling only a few, close friends.

Only 24 hours before his body was discovered, Oliver's secret was ended. He was summmoned to a Northern Virginia courtoom to answer charges of performing a homosexual act in a public restroom. The charge, sodomy, is a felony.

A gay activists and Oliver's lawyer piece together details of his methodical suicide, they bitterly complain that his death is directly attributable to the tough stance Fairfax County prosecutors have taken toward homosexual acts. Prosecutors "all but turned on the gas" that killed Oliver, charges his attorney, James M. Lowe, an Alexandria lawyer specializing in gay rights cases.

Unlike most Washington localities, which treat homosexual acts performed in public as misdemeanors, Fairfax prosecutors are invoking against homosexual suspects a felony law that carries a penalty of up to five years in prison.

It was that law that the prosecutors invoked against Oliver and another man who were allegedly caught April 8 in a homosexual act in a public restroom at the Tysons Corner shopping center.

Fairfax chief prosecutor Robert F. Horan, a hardline law and order advocate, said he is merely enforcing state laws that are on the books. It would be wrong, he said, for his office to routinely reduce what are felony sodomy charges to misdemeanors. "I would be setting myself up with veto power over the Virginia legislature" if the charges were lowered, Horan says.

The Horan assistant who decided to prosecute Oliver for a felony said his sole objective was to discourage homosexuals from engaging in sex in public restrooms. In recent months, several other homosexual suspects have been arrested in the same restroom at the Tysons Woodward & Lothrop department store, according to assistant Fairfax prosecutor William J. Schewe Jr.

"A bunch of us [assistant prosecutors] were sitting around one day and somebody brought up that this was kind of getting out of hand, and we ought to do something about it," Schewe said.

"I don't give a tinker's damn about what somebody does in their own bedroom," Schewe said. "But there ought to be some limits about what society permits in public. A couple of us said we don't want our sons seeing it," he said.

With that, Schewe said, the Fairfax assistant prosecutors abandoned their practice of reducing the sodomy charges to disorderly conduct, a misdemeanor, and began trying homosexuals on felony sodomy charges. Schewe said the prosecutors believed many of the homosexual suspects were government and professional men who could easily pay the nominal fines that accompany misdemeanor convictions, but that homosexuals could not ignore felony convictions.

Although officials at Woodward & Lothrop, where Oliver was arrested, disclaim any problems with homosexuals at the Tysons store, the chain has a policy of insisting that criminal charges be pressed against anyone arrested in its stores, according to Lewis Shealy, the company's vice president for security. What criminal charge is filed, however, is a decision the company leaves to prosecutors, Shealy said.

Lawyer Lowe and gay activists in the Washington area charge that it was unjust for Oliver to be accused of a felony for an incident that involved sex between two consenting adults. "You don't put somebody in the electric chair for shoplifting," angrily said Frank Kameny, a leader in the District's gay community.

Other Virginia and Washington-area prosecutors said they usually charge homosexuals arrested in public restrooms with misdemeanors, such as disorderly conduct or indecent exposure. The penalty is usually a fine of $100 or less.

Oliver had been arrested in the District of Columbia, for example, he would not have been prosecuted and the misdemeanor charge would have been dropped, according to James Owens, the chief of the misdemeanor section in the U.S. attorney's office.

Owens said charges against first-offenders in homosexual cases are routinely dismissed on the condition they spend six hours observing court proceedings and write an essay on their encounter with the legal system.

"We never prosecute for felonies" in cases involving consenting homosexual adults, Owens added. "Our concept is that we don't want to legislate these types of things," he said.

For Oliver, a $14,000-a-year (GS-7) computer operator for the Army, the felony charge could have been ruinious, Lowe contends. His arrest on the felony could have cost him his security clearance and his job, the lawyer says. f

Lowe said Oliver was not the only one of his homosexual clients to suffer from Fairfax prosecutors' tough policy on restroom arrests.

"I died a thousand deaths since it happened," said one of his clients who was recently charged and convicted on sodomy charges there. "But I never contemplated killing myself."

The man, who asked not to be named, said he quit his longtime, $30,000-a-year government job rather than be fired and face embarrassment from his colleagues.

He said he plans to move from the Washington area when his case is completed. "I'll try to put all the pieces together and start all over again," he said.

Prosecutor Schewe said he was "very sorry" about Oliver's death. "I was upset enough that I called up my father to find out his reaction." Even so, Schewe said he intends to pursue the felony charge against the man arrested with Oliver.

Schewe said he would not have asked the judge to sentence Oliver to prison and had told Lowe he also planned to ask the judge to withhold imposing a formal conviction on Oliver's record, if he had been found guilty.

Kameny said most people are unfamiliar with the courts and are ignorant of such possible sentences. "The presentment of a grand jury indictment is in itself terrifying . . . (and) they (the suspects) obviously panic," Kameny said.

One of the Oliver's friends said that Oliver, a North Carolina native, had been depressed before his arrest. "He was lonely and concerned about aging," the friend said.

The court case was the "final straw" that led to his death, the friend said.

The friend said Oliver never told him about his arrests, but the day before Oliver went to court last week "he was just miserable. He called me Tuesday and said he couldn't be alone."