Felicia Ruffin sat in the courtroom for more than six weeks, arms clasped around her body, one knee jerking up and down endlessly, eyes darting pleadingly toward her grandmother, who sat faithfully in the audience as Ruffin and nine other young persons were tried for the murder of Catherine Fuller.

Yesterday was no different, until a few moments before 3 p.m., when Judge Robert M. Scott began, "With respect to the charges against defendant Felicia A. Ruffin . . . " and the jury foreman pronounced the words "not guilty" four separate times, regarding kidnaping, robbery and charges of first-degree murder.

Ruffin, 17, suddenly was a free woman. She shook her head in seeming disbelief, dropped her face into her hands and rocked back and forth.

"Thank you, Jesus," whispered her grandmother, Mary Ella Ruffin, as each verdict was read.

Moments earlier, another of the 10 defendants in what has been called one of the most brutal and inexcusable crimes in the District's history also had been "cut loose," as the lawyers put it: found not guilty of the four charges against him.

Alphonso L. Harris, 23, flashed a broad grin as he sat with the trial's other principals in the courtroom well, separated from spectators by a shield of bulletproof glass.

"Oh my God," screamed Harris' mother, Helen Brooks, nearly three hours later as Harris, known since childhood as "Monk," stepped out of the cellblock at D.C. Superior Court and into her arms.

But it was a day for counterpoint, and nowhere was this more evident than in the nearly emptied courtroom minutes after the verdicts, when Harris' lawyer shouted to a friend: "We saved him, we saved him."

At that moment the mother of defendant Steven Webb, who had been found guilty on all charges, walked into the room, collapsed in a chair and sobbed uncontrollably.

"I know he didn't do it," Earlene Gamble said. "I know where he was. I don't believe it."

The courthouse betting had been that if anyone were found innocent in the Oct. 1, 1984, fatal beating, it would be Ruffin and, possibly, Harris. Both had been identified by fewer eyewitnesses than the other defendants -- Harris by two and Ruffin by one.

The two had other things in common. Neither was a mainstay of the group that regularly hung out at the park at 8th and H streets NE, where prosecutors charged that the crime was hatched. And both Harris and Ruffin were born to mothers who were 14 years old when they became pregnant, according to family members.

Harris, the second of five sons, had dropped out of school, like many of the other defendants. But unlike the others, friends say, he was shy and introverted, and had a major interest: working on cars and occasionally holding car repair jobs.

He has sickle cell anemia and, according to authorities, an attitude that said, "I'm going to die, so I don't care." But his mother, who works at the Department of Justice in support services, said his illness gave him "a positive attitude."

Harris had been found guilty in 1981 on charges of carrying a dangerous weapon and unauthorized use of a vehicle, and was placed on probation in both cases, according to authorities.

Yesterday, Harris, back at his grandmother's Northeast home for the first time in more than a year, said: "I did my best to prove that I didn't have anything to do with Mrs. Fuller's death. I can just hope and pray they believe me."

Ruffin, who was back at her home last night, asserted that she wasn't at the scene of the slaying, but added: "I thought all of us were going to be convicted. I didn't know if I was going to get out or not."

The youngest of the defendants and the only woman on trial, she was raised by her grandmother, who attended the trial every day and spoke proudly about Ruffin as a choirgirl and usher at the Greater Union Baptist Church in Southeast.

She said Ruffin dropped out of school and church activities recently, had been working at McDonald's and Popeye's restaurants, and had tried her patience by staying away from home for days at a time.

"Many times, I'd get down on her real hard and try to tell her what that word 'education' meant," said Mary Ella Ruffin, the grandmother.

But Felicia Ruffin had been arrested as a juvenile for assault with a deadly weapon, according to sources. And yesterday her mother, Jacqueline Ruffin, said: "I think this is a lesson to be taught, to try to keep distance from the wrong people and to keep from being in the wrong place at the wrong time."