In 1962, lawyer Arthur (Bud) Marshall Jr. launched his first campaign for the office of state's attorney in Prince George's County, promising a "new look . . . for a new era." The former New Yorker won that election and has been the county's chief prosecutor ever since.

Nearly 25 years later, Marshall is running in the Democratic primary against a man who once worked for him, law professor and attorney Alex Williams. The 37-year-old Williams is telling the voters that it is time for a new face, for a person who can "lead the county into the 1990s."

Debate between the two Democrats, who will face each other in the primary election Sept. 9 in the heavily Democratic county, has begun. Marshall has taken the offensive, attacking Williams' connections with County Executive Parris Glendening and two of his top campaign advisers who are also attorneys for Prince George's General Hospital board.

"Who is he obligated to?" Marshall asked an audience at a recent meeting. "I'm not obligated. I don't owe anything to anyone."

Williams, on the other hand, is quick to tell an audience that he is not attacking his "friend, Bud Marshall," even as he criticizes Marshall for sometimes moving death-penalty cases out of Prince George's County and for what he says is Marshall's unwillingness to work with the County Council and executive's office.

The candidates spoke last week to the Prince George's County Federation of Civic Associations, the clean-shaven and fiery 56-year-old Marshall wearing a sports coat and slacks, Williams, bearded and soft-spoken, clad in a three-piece pinstriped suit.

The two men have different ideas about how the office of state's attorney should be run.

Marshall seeks the death penalty in any case that fits the criteria, where a victim is killed during a robbery, for example. Williams also supports the death penalty, but thinks the prosecutor should be more selective in choosing capital cases.

Williams thinks the office should have a unit that concentrates on prosecuting drug cases, should offer additional training for young prosecutors and should give more attention to cases involving nonviolent offenses such as consumer fraud, tax evasion and municipal infractions. marshall thinks his office is working fine, and he cites a 93 percent conviction rate as proof.

In spite of the apparent differences in the two men's styles and philosophies, Prince George's Democratic leaders have not yet decided whom to support in the September primary. Although a spot on the local party's ticket does not carry the weight it did as recently as two years ago, it is still a political plum that brings wider publicity and more campaign funds.

Marshall "has never had a hint of any scandal or any type of dishonesty in his 24 years in public office," said state Sen. Thomas V. Mike Miller Jr., head of the county delegation to the General Assembly.

"He's known as tough on crime' his civil rights record is outstanding . . . When you look at all of his credentials, you say the man's an outstanding state's attorney.

"Alex Williams is one of the nicest guys you'll ever meet in the world," Miller continued. "Everybody I know concedes that he is a good attorney and would make a good state's attorney."

The state's attorney's race presents a hard choice for Prince George's Democratic leadership because Marshall, a maverick politican who says he owes no political favors, has strong name recognition throughout the county.

If it decided not to support Marshall, the party leadership would risk alienating a candidate who tallied in excess of 5,000 votes more than Glendening in the 1982 general election.

With Williams, one of the first blacks to run for a countywide office, the Democratic leadership has an opportunity for sharing power with the county's growing black population, several black leaders said.

In bypassing such an opportunity, the leaders said, the party would risk alienating the huge black voting bloc in Prince George's -- one that is expected to turn out in large numbers to vote in the primary because of U.S. rep. Parren J. Mitchell's candidacy for lieutenant governor on the gubernatorial ticket of state Attorney General Stephen Sachs.

"Party leadership has got to consider the impact of Parren's candidacy on Alex's campaign," said Del. Albert Wynn (D-Prince George's), a state Senate candidate and Sachs supporter. "I'd be surprised if they don't come down on Alex's side."

As of last week, party leaders hadn't decided which candidate to support. Rep. Steny Hoyer, the Democrat who represents much of Prince George's in Congress, would not comment on the state's attorney's race.

Glendening, who appointed Williams to the Washington Suburban Sanitary Commission and has had turf battles with Marshall, attended a Williams fund-raiser last week. But Tim Ayers, Glendening's spokesman, said the county executive has not formally endorsed either candidate. "But I guess you could call it significant that he attended the fund-raiser," Ayers said.

Miller said it is likely that no decisions will be made until after the June 30 filing deadline.

One scenario suggested by several party members, including some elected officials, would have Marshall withdraw from the race in exchange for party leadership's support for the next circuit court judgeship in Prince George's, a post that Marshall acknowledges he would like. Marshall ran unsuccessfully for two circuit court seats in 1984, without the party's backing.

Marshall said no one has spoken to him about this scenario. But he said he has heard the talk and is not interested.

"I wouldn't trust the county Democraratic leaders as far as I could throw them," Marshall said.

Neither candidate is saying publicly he expects to be on the party ticket. Marshall said he has always run "against the Hoyers and Millers" -- the elders of the Prince George's Democratic party. Williams acknowledges that his lack of political experience doesn't help his chances.

Both men have raised about $60,000 for their campaigns, and they said they expect the electioneering to become more heated as the primary draws nearer.

"I'm in this one until the end," Williams said.