Pretrial hearings in the politically charged Brink's Inc. robbery case, in which former Weather Underground leader Kathy Boudin and five other radicals stand charged with the murder of two police officers and an armed guard nearly a year ago, deteriorated into a noisy free-for-all today.

Four defendants walked out of the courtroom and the judge threatened to hold their attorneys in contempt of court when the lawyers attempted to follow suit.

"I am not an American citizen, I'm a victim of America," said defendant Nathaniel Burns as he insisted on leaving the courtroom. "I do not need a lawyer because I am not a criminal."

The four lawyers said that since their clients were not participating and their clients had told them not to participate, there was no reason for them to remain.

"For you to leave would be tantamount to your abandoning your clients," said Judge Robert Stolarik, who said he considered the lawyers "attorneys of record."

Angry defendants, some of whom say they are members of the Black Liberation Army's "revolutionary armed task force," jousted throughout the day's proceedings in Rockland County Court over their right to wear black armbands and their right to defend themselves. There were shouts of "free the land" from the defense table and calls for decorum from the bench. The statement of Burns, who repeatedly told the court he wished to be identified as Shakur Odinga, was characteristic.

"I do not recognize the right of this court to try me," he said. "I'm a freedom fighter and a prisoner of war -- free the land!"

"Free the land," came the echo of voices from the visitors' row.

The defendants are charged with participating in the botched stickup of an armored Brink's truck carrying $1.6 million, and a subsequent shootout that killed a guard and two Nyack policemen.

In the wake of that shooting, police captured former Weather leaders Boudin, Judith Clark, and David Gilbert, as well as Black Liberation Army members Donald Weems and Burns. A sixth suspect, Samuel Brown, was reported to have an extensive criminal record but was not well known as a political activist. All were charged with murder and attempted robbery.

As the pretrial hearings began here last week, however, some defendants denounced the charges.

"I am a revolutionary. I do not recognize the validity of this court to try us. I do not plan to take part in the proceedings," Clark, 32, told Stolarik.

Flyers and statements, passed out among the crowd of 50 demonstrators by a group called "The Coalition to Defend the Oct. 20th Freedom Fighters," also took a political view of the robbery, saying that the defendants had attempted to "expropriate" funds that were rightfully theirs.

Today, the fourth day of the hearings, the combative and politicized atmosphere continued, though the most famous of the defendants, Boudin, 38, was conspicuous by her silence.

Her father, prominent civil liberties lawyer Leonard Boudin, sat occasionally by her side. Like the other defendants, she refused to rise when the judge took the bench. (Her father did stand when the judge entered the room.) Nor did Boudin and Samuel Brown rise and leave the courtroom when the other defendants chose not to remain.

Arguments between the four other defendants, their attorneys, and the judge began almost from the moment the hearings convened in early afternoon.

Defendant Weems complained that he and the others had been forbidden to wear black armbands in solidarity with those massacred in the Palestinian refugee camps in Beirut. There were also complaints that the sheriff's office had not allowed the defendants to wear red T-shirts with political slogans on the back.

"We wanted to wear red T-shirts with slogans, which were clearly objected to because of their politics," said Clark.

"You allow the sheriff to wave the American flag, the sponsors of the massacre," Gilbert yelled.

The judge, insisting that the sheriff's decision was not within his domain, refused to decide the T-shirt question.

Pretrial hearings are expected to be lengthy.