The prosecution's key witness in the bribery trial of former D.C. Superior Court Judge Robert H. Campbell had just started testifying in federal court last week, recounting minor details of his military service in the 1950s, when defense lawyer Jacob A. Stein jumped to his feet and protested that the information was irrelevant.

Judge Thomas A. Flannery overruled Stein, noting that the testimony was the standard personal background provided by any witness. As Stein sat down, Assistant U.S. Atorney John P. Hume, who was questioning the witness, turned from the podium and glared at Stein, one of several defense lawyers in the case.

The judge was annoyed. "Don't turn around and look at counsel," Flannery snapped at Hume.

That momentary flareup was a sign of the friction that has intensified between the prosecution and the defense in the months since Campbell was charged with accepting $10,000 in bribes and favors from Excavation Construction Inc. (ECI) in exchange for dismissing hundreds of thousands of dollars worth of overweight truck tickets issued to the Maryland-based construction firm.

The incident in U.S. District Court last week was also illustrative of what is expected to be an extraordinary rough courtroom battle with dimensions far beyond the normal legal give-and-take of a criminal trial.

The case is not just a forum for the 56-year-old former judge to attempt to vindicate his professional reputation. It is his chance to put the D.C. Superior Court on trial, especially its once overburdened and arbitrary traffic court system.

Moreover, Campbell's attorney, R. Kenneth Mundy, made it clear to the jury last week that he will not hesitate to raise racial issues as he unfolds the defense of his client, a black man.

"We are now at the moment of truth," Mundy told the jury of 11 blacks and one white.

In his opening statement to the jury, Mundy noted that campbell was not the first judge at the Superior Court to discount or reduce fines for overweight truck violations, a practice which Mundy described as "normal procedure." And, Mundy said, there was controversy between the police department and the city prosecutors office about whether the law was being enforced fairly. But for Judge Campbell, Mundy said, there was another aspect of truck ticketing in the District.

Campbell, he said, used to sit in his office at the courthouse and watch as white police officers, assigned to the construction site for the new FBI building, waved some overloaded trucks by but were "pouncing" on black drivers who made up most of the ECI fleet. Mundy said white police officers also singled out drivers from the predominately black-owned hauling company known as Rice and Williams, which had been set up with financial help from Eci. ECI is owned by two white men, including Campbell's co-defendent, Larry A. Campbell.(No relation to the former judge.)

Earlier, Mundy told the jury of the judge's impoverished childhood years when "being black was anything but beautiful," adding that Campbell's memories of his upbringing "carried over in his administration of justice."

Mundy said it was important for judges to reduce fines on overweight tickets because the tickets themselves were issued to "the poor, individual driver. And in the case of ECI drivers, they were mostly black drivers." There was testimony from black ECI drivers during the trial last week, however, that they turned their tickets over to company officials and did not pay the fines themselves.

Seven present and former judges of the D.C. Superior Court are at the top of the list of witnesses Campbell may call in his defense, including former Chief Judge Harold H. Greene, now a federal judge here. The others are judges William Gardner, Eugene Hamilton, Samuel Block, Byron Sorrell, Milton Korman and George Neilson.

Much of the list of possible witnesses for Campbell reads like a Who's Who of Washington's older, black middle-class community, including former mayor Walter E. Washington, former D.C. School Superintendent Vincent Reed, D.C. teacher's union president William Simons, and Charles Duncan, a former D.C. Corporation Counsel and former dean of the Howard University Law School, where Campbell received his law degree. And there's an array of black clergymen, including Bishops Smallwood Williams and Walter McCullough.

There are a few black lawyers practicing in the local court who routinely use racial issues as a trial strategy to gain sympathy for their clients before predominantly black juries, and some, like former Superior Court judge Harold T. Alexander, have themselves become emotional symbols of those issues. But lawyers not involved in the Campbell case who know Mundy say that if he raises a question of race at a trial, he does not do so casually but as a carefully calculated legal tactic to gain his client's acquittal.

"It depends on who does it and how it is done," commented a black defense attorney, who added, however, that he would not be inclined to use that technique. Mundy is widely respected for his defense work in some exceptionally tough cases, including the murder trial of Prince George's County teen-ager Terrence Johnson. He is viewed as an accomplished lawyer, not a showman, lawyers said, so when he raises a racial question it is seen as more than just trial rhetoric. He is expected to come up with the evidence to back up his claim, these lawyers said.

Otherwise, "I think it's a racist argument," one white defense lawyer commented. "A jury's function is to overlook buzz-word kinds of agruments, arguments that draw on emotions," he said.

For the U.S. Attorney's office, the stakes are particularly high in the Campbell case. After a lengthy, difficult investigation, a former judge of this city has been charged with corruption in connection with his official duties in what is believed to be the first case of its kind here.

The government charges that as a city prosecutor and later on the local bench, Campbell, who was appointed to the court in 1972, accepted money and favors from ECI.Assitant U.S. Attorney Carol E. Bruce told the jury that in return, Campbell dismissed hundreds of thousands of dollars worth of tickets for overweight load violations issued to the company's familiar red, white and blue dump trucks.

Payoff money was allegedly brought to Campbell by Robert Payne Jenkins, once a high ranking ECI official, whom the government describes as the company's "trusted bag man." Between 1975 and 1977, prosecutors say Jenkins made seven payments to Campbell for a total of $10,550 in bribes. During that time, they say, Campbell dismissed more than 1,000 overweight truck tickets for ECI, worth more than $100,000 in fines.

Campbell, who abruplty retired from the court on full medical disability in December 1978, is charged with conspiracy, bribery and racketeering. His two co-defendants, facing the same charges, are Larry Campbell, 44, who is ECI's general manager and co-owner, and the corporation itself, which is represented by attorney Stein.

Last week, various ECI employes testified that they did favors for the judge at the direction of their supervisors, including delivery of three mounds of topsoil and moving his household furnishings from one location to another, after which Campbell gave the men $60. There was also evidence that $55 worth of drain work was arranged for Campbell and paid for on Jenkins' credit card. Another witness, a former police officer who was working for ECI after his retirement, testified he delivered two envelopes to Campbell from ECI sometime between 1971 and 1974. The witness testified he had no idea what was inside the white letter-sized envelopes.

Robert Jenkins, the government's key witness, will resume his testimony today. Arnold M. Weiner, who represents Larry Campbell along with attorney Gerard P. Martin, told the jury earlier that Jenkins was a man "leading a double life," supporting an illicit love affair with an Army nurse with the money the government said he was using to pay bribes.

Every defense lawyer in the case has pointed the finger at Jenkins, 50, once a close confidant of Larry Campbell and now convicted of perjury in connection with the federal grand jury investigation of the case.

The government theorizes that Jenkins lied to the grand jury to cover up the alleged bribery scheme for ECI. But, the government says, Jenkins was terminated by ECI last September after it was learned that he was cooperating with the government in the Campbell case. Now, the government says in court papers, the defense is making the "predictable claim" that Jenkins acted on his own.

Mundy told the jury that Jenkins was keeping the money he withdrew from company accounts for himself -- the money the government contends was used for bribes.