On his first day of freedom in 438 days, Alphonso L. Harris returned to the courtroom in D.C. Superior Court where on Monday he was found not guilty of the brutal murder of Catherine Fuller and where yesterday a jury continued to deliberate the fate of the remaining two defendants without reaching a verdict.

Wearing purple jeans and a jaunty grin as he stood waiting to get into the courtroom, Harris, known as Monk, said nonchalantly, "I'm here to see my friends." His presence caused a stir among courtroom regulars, one of whom remarked, "If I were him I'd be on the first bus to North Carolina."

Harris, 23, was one of two young people -- among the 10 accused of Fuller's murder -- to be acquitted when the jury returned with its partial verdict late Monday. Six were found guilty of felony murder, kidnaping and armed robbery.

But yesterday Harris faced his accusers on a different ground.

"So you still think I'm guilty?" Harris said to an approaching Detective Donald Gossage in the courthouse cafeteria at lunch time in full view of gawking onlookers.

"The jury found you not guilty. I'm going to shake your hand for it," responded a smiling Gossage, who became a nemesis to many of the Fuller suspects during the year-long investigation as he ferreted out some of the most reluctant witneses.

"But you found me guilty," Harris was overheard insisting to Gossage.

Gossage also had a special relationship with Harris. In 1979, Harris shot Gossage in the leg with a BB gun during another investigation, according to court papers. Later yesterday the two spoke intently for about 20 minutes in the basement lobby, with Gossage at one point putting his arm around Harris' shoulder.

In another exchange, Detective Patrick McGinnis said "Hi, buddy" to Harris, as McGinnis passed him in the hall. "Buddy?" responded an incredulous Harris.

"I've got four more years before I retire," McGinnis shot back over his shoulder as he walked on. McGinnis was one of two homidice detectives assigned to the case.

Finally, by the time prosecutor Jerry S. Goren decided to make a pass down the hall, the beseiged Harris merely shook his head when Goren nodded, "Mr. Harris."

Harris later told a reporter he had come to court because "they're still my friends . . . . I still got friends."

Harris had attempted during his trial testimony to distance himself from the other nine young persons on trial because the plot to rob Fuller allegedly was hatched during a regular afternoon gathering of friends. During his account of how he spent the day Fuller was killed, Harris testified he knew few of the accused, but acknowledged that he had played football with "Chrissie," whose last name he did not know.

"Chrissie" is Christopher D. Turner, one of the defendants whose fate the jury is still deliberating; the other is Russell L. Overton. Harris came to court yesterday with a young man who described himself as Turner's best friend.

Harris' attorney Michele Roberts said yesterday her client was "not down there trying to play hide and seek" and that Harris had left numerous messages looking for her and Corinne Schultz, Harris' other lawyer. Roberts added she was not surprised that Harris was concerned about Turner.

As to Harris' courtroom exchanges, Roberts said "there is understandably some tension between the police and Mr. Harris because they didn't believe him."

Later in the day, a deputy U.S. marshal who had come to know Harris during the proceedings took Harris aside and advised him to leave the courthouse.

Harris dodged out the back door to avoid waiting television crews and walked with a reporter to a friend's silver Camaro. When asked how he was going to spend the remainder of his first free day, Harris responded "free."

A young woman passed and Harris spun in his steps. "There's a pretty girl."