Four years ago, facing reporters and cameras in the Prince George's County courthouse, the county's top prosecutor, Arthur A. "Bud" Marshall Jr., made an announcement that clearly pained him. After nearly a quarter of a century, he had been voted out of office, and, in a voice cracked by emotion, he conceded:

"I've pretty much concluded my career in public service. If anybody wants a prosecutor with 24 years' experience, I'm available."

A few months later Marshall was gone. Alex Williams, a reform-minded law professor with a style far removed from Marshall's blunt, sometimes hot-tempered nature, and the first black to gain countywide office in Prince George's in a dozen years, was sworn in as state's attorney.

That was then. This is now: "Remember," said Marshall, smiling one afternoon last week, halfway into a full day of campaigning for his old job, "I said 'pretty much concluded.' . . . I left myself a little room."

And then he laughed, because after four mostly "unhappy" years in private law practice -- a generally dull experience, he said -- Marshall is back in the hunt for elective office. "And I'm enjoying it," he said.

"I live five minutes from here," said Marshall, sitting in an Upper Marlboro office condominium he purchased a few months after losing to Williams. "I've got a nice office. The courthouse is close. And I'm probably doing a little better than making a living. I'm making as much as if not more than I was making as state's attorney, and I enjoy the contact I have with people.

"But I miss being state's attorney," Marshall said.

And he thinks the county misses him.

Marshall, 59, was elected in 1962 as a Democrat and reelected by wide margins five times, building a reputation as an outspoken, hard-line prosecutor and garnering his strongest support among voters in the county's rural precincts.

He rarely shrank from publicity, clashing with judges whom he considered soft on criminals, seeking the death penalty in every case where the law allowed it, and asking for changes of venue for murder trials when he thought local juries might be reluctant to impose capital punishment.

But in 1986, with the largely white Prince George's Democratic elite wanting black representation in a countywide office, Marshall was replaced on the party's slate by Williams. The move came as Marshall was facing criticism for what many perceived to be his overzealous investigation of the cocaine-induced death of University of Maryland basketball star Len Bias.

Some Prince George's Democrats attributed Williams's upset victory in the Democratic primary partly to Marshall's handling of the Bias case. Critics accused Marshall of trying to gain political mileage by directing an overly broad grand jury investigation of drug use on the College Park campus and by making incautious public statements about the probe.

Now, in his comeback attempt, Marshall has cast himself as "a committed prosecutor," a career "law-and-order" man, trying to unseat an incumbent he describes as "a professional politician" using the prosecutor's post as a launching pad to higher office. This time around, though, Marshall is a Republican.

Democrats outnumber Republicans by better than 3 to 1 in Prince George's, and Marshall said his campaign will spend about $50,000, compared with more than $100,000 in 1986. Williams, heavily favored to win, said he expects to spend more than $150,000.

Williams has described Marshall as a man whose time has gone by, a desperately bored ex-public official looking for a return to prominence, waging a negative campaign.

Marshall calls Williams "soft on crime."

"I remember going out and talking to every attorney we hired," Marshall said. "And I'd tell them they had a great job. They're on the side of apple pie and motherhood, the side of the American flag . . . . Your job is to represent the victims of crime, to represent police agencies. Your job is to put bad guys away.

"And I don't think Alex feels that way," he said. "I think Alex feels he's sort of a grand jury. He feels he's there to protect the citizens from the system, to protect them from overzealous police officers."

He was referring to the most controversial case of Williams's tenure, that of Gregory Habib, a native of Ghana who died in a May 1989 struggle with four white Prince George's police officers. Williams criticized a grand jury for issuing only misdemeanor indictments.

"I believe police officers, like teachers and parents, all have the right to use force," said Marshall. "I used to like to believe I had a concept of what a police officer goes through out there on the street. I don't think Alex has a concept of that, and he thinks differently."

He accused Williams of padding the office administrative payroll through politically inspired hiring, an allegation Williams denies.

Marshall also has told audiences that in its first two years, Williams's office achieved a conviction rate of only 62 percent. "Those are his own figures," Marshall said, referring to a midterm report published by the State's Attorney's Office. Williams, however, accused Marshall of twisting statistics that actually show a conviction rate of better than 90 percent. Marshall gets his figure by comparing convictions, not counting plea bargains, to the total number of cases. Williams compares convictions, including plea bargains, to the number of cases that were settled.

Williams's supporters describe him as a strong prosecutor, yet one more sensitive to the growing black population in Prince George's, which has reached about 50 percent. But Marshall scoffed at the argument.

"I don't think the job is to be compassionate," he said. "I don't think the job is to protect citizens. I think it's the police department's job to protect citizens. And I don't think the job is to stand between police agencies and citizens in the community who feel they've been brutalized.

"I think the job is to investigate," he said. "We had people who made allegations of police brutality. The police investigated, and if they thought {the allegations were} justified, they would bring a case to the state's attorney. We had a number of prosecutions. And we probably had a couple of convictions over the years. But those were serious cases."