D.C. Superior Court Judge Robert M. Scott denied a mistrial in the Catherine Fuller murder case last night after a dramatic court appearance by a juror who was summoned to the witness stand after it was revealed that her daughter knew several of the defendants on trial.

Juror Rita Weaver, brought to the court by U.S. marshals under orders of the judge, took the witness stand and asserted that she "did not know" her daughter "was acquainted with any of the people here on trial."

Her daughter, 15-year-old Natasha Weaver, also took the stand and acknowledged that she did know three defendants, but said she had never discussed that fact with her mother.

The threat of a possible mistrial hung over the proceedings for hours when the extraordinary late-night session was set in motion by a sobbing teen-ager, who informed the court that Weaver's daughter "knew" and "went with" some of the defendants.

The revelation came moments after the jury had gone home without reaching a verdict in its fourth day of deliberations in the case of 10 young persons charged in the Oct. 1, 1984, beating death of Fuller.

The teen-ager, 16-year-old Darnella Perritt, also said that Weaver had visited her home Wednesday night and argued about the case with Natasha, telling Natasha, "You might as well tell all your little boyfriends 'bye. They're all going to jail." Weaver testified that she had neither seen Perritt nor visited her home that night.

After hearing all the testimony, a furious Judge Scott said he had "no question but that the girl is an absolute liar," and asked the U.S. attorney's office to take action in the case. Scott had previously warned Perritt, as he placed her under oath, that "anything not true subjects you to a perjury charge . . . . It is a felony."

The girl's surprise statements added yet another wrenching moment to one of the most dramatic trials in the city's history. The judge, the prosecutor and defense attorneys appeared shocked by the girl's allegations, which, if true, could form the basis for a mistrial in the final leg of a case that has taken five weeks to present to the jury and a year to investigate.

When defense lawyer Greta Van Susteren moved for a mistrial, she was cut off in midsentence as Scott said, "Motion denied."

Scott ordered the juror to return to court today, but said he had not yet made up his mind "if there is any reason she could not be totally impartial." Under a recently promulgated D.C. Superior Court rule, the judge could excuse a juror and allow the remaining members of the jury, normally composed of 12 persons in a criminal case, to complete their deliberations. Alternate jurors are excused at the start of deliberations.

One defense attorney muttered after the proceedings ended that the case "screamed for a mistrial," while defense lawyer Allan Palmer disagreed, saying, "I want a verdict." A third said, "The bizarre thing is, no one knows who's telling the truth."

Yesterday's late-night session was surrounded by heavy security precautions. Before Weaver took the witness stand, a bullet-proof glass screen was drawn to separate the courtroom well from the overflow audience, and more than a dozen extra U.S. marshals poured into the court.

Perritt's dramatic testimony came after she made similar allegations to defense lawyer Lillian McEwen moments after the judge had excused the jury for the day.

McEwen, who represents Levy Rouse, escorted the trembling Perritt to the judge's stand where Scott recalled departing lawyers and told the teen-ager to repeat her story under oath.

During her testimony, several defense attorneys slumped in their seats and others shook their heads. Assistant U.S. Attorney Jerry S. Goren, who has worked on the case for more than a year, looked solemn and Judge Scott, normally vigorous in his comments, was shocked into silence at one point.

Perritt, who spoke haltingly and tearfully throughout the proceeding, said Weaver and her daughter had arrived at Perritt's house Wednesday evening to pay Perritt's aunt some baby-sitting money. She said she had known Weaver's daughter, Natasha, for about seven years and that Weaver's other daughter lived with the Perritt family.

The three began "fussing" about the case, Perritt said, when the elder Weaver made the comment about "all your little boyfriends . . . going to jail".

Weaver was "mad" with her daughter because Natasha "used to like" defendant Kelvin Smith, Perritt said. When Natasha said, "Mama, I don't know why you're saying that. I feel all of them are not guilty," Perritt said the elder Weaver repeated her comment.

Perritt had earlier told the same story to a Washington Post reporter during an interview with Perritt and a girlfriend of Levy Rouse's. Perritt, however, told the reporter her name was Chiquita and said she was 21 years old.

Perritt, dressed in a royal blue leather suit, acknowledged to Judge Scott that she had visited defendant Rouse in jail earlier Wednesday night with his girlfriend, with whom she had become friends during the trial. She also said she "used to like Timothy, Timothy Catlett," another defendant, and had sent her photographs to Catlett in jail.

Pressed by Goren whether she "cared" about the verdict, Perritt said, "I guess I care if they go to jail or if they don't go to jail."