A hearing at D.C. Superior Court yesterday turned into pandemonium when a defendant tried to place the judge under "citizen's arrest," dragged a deputy U.S. marshal, a clerk and an attorney behind the bench, knocked over a flag, overturned chairs and nearly reached the judge before he was finally restrained, courtroom witnesses said.

Corridors outside the courtroom were suddenly filled with a prosecutor's screams for help, and D.C. police in the vicinity rushed to the scene, reaching for their guns, witnesses said.

No one was seriously injured in the melee, but at one point the defendant as well as those trying to subdue him tumbled to the floor behind the bench while Judge W. Byron Sorrell and astonished courtroom spectators looked on.

The incident capped a bizarre series of court proceedings over several months this year involving a defendant who insists that the CIA is responsible for at least three murders and has tried to arrest, or subpoena, numerous high-ranking government officials, including CIA Director William Casey.

The defendant, Harry Zain of Charleston, W. Va., was eventually removed from the courtroom yesterday and taken to the court's cellblock after half a dozen deputy U.S. marshals responded to calls for help.

After the incident, Chief Judge H. Carl Moultrie I signed an emergency order transferring Zain to the Ugast Center at D.C. General Hospital for psychiatric examination.

Zain had been ordered to appear in court yesterday to determine whether he should be released from jail pending a decision on whether he is mentally competent to stand trial on misdemeanor charges of simple assault and disruption of Congress. The charges were filed against him following an incident on April 27 in which he allegedly attempted to arrest former CIA director Stansfield Turner during a House subcommittee hearing.

Zain, who told the court he would represent himself, has been held in lieu of $2,000 bond.

Before the melee yesterday, a CIA attorney told Judge Sorell in court that Zain had written several CIA officials concerning his allegations and had sent Casey a letter at his home in suburban Maryland, threatening to arrest the director.

Prosecutors argued that Zain should be held pending a determination on his mental competency. Sorrell, who recently had held two other hearings on Zain's bond, was speaking from the bench, asking Zain whether he would cease his threats and stay away from government officials, when Zain interrupted.

"Your honor, I cannot let the CIA go unprosecuted for murder," he said. "I charge you with being an accessory to murder. I'm going to take custody of you. I am, as a citizen, arresting you for attempted murder."

"Everyone assumed he was just running off at the mouth," a clerk in the courtroom said later.

But Zain walked around the defense table toward Sorrell and had nearly reached the bench when a deputy marshal grabbed him. Zain then pulled the law officer behind the bench, knocking over the American flag, while the judge's clerk and an assistant U.S. attorney in the courtroom joined the struggle to stop him.

According to one clerk, Zain gave up the fight to reach Sorrell, saying, "I appear to be outnumbered."

Zain gained attention two years ago when he tried to have Congress pass a law that would allow him to marry a 12-year-old girl in his home state.

A further hearing in the matter is scheduled for Nov. 1.