Christopher D. Turner, one of the defendants charged in the slaying of Catherine L. Fuller, told a D.C. Superior Court jury yesterday that on the day Fuller was killed he was lounging around his best friend's house, watching television and talking on the telephone.

Turner, 20, testified that he and Kelvin D. Smith, 20, another defendant, spent the day at Smith's house and never left it after hearing about Fuller's death in a nearby alley because of a fear that they might be "pulled . . . into it."

"It was a rainy day, a Monday, a lazy day," said Turner. "We just laid around . . . . "

Turner's testimony was detailed and precise as he carefully accounted for his movements by television shows like "One Life to Live," "The Love Boat" and the cartoon "Inspector Gadget." Rarely faltering, Turner gave an account that contrasted sharply withthose of several other defendants in the past week, including his brother Charles S. Turner. Other defendants often appeared confused as they attempted to place themselves elsewhere on Oct. 1, 1984, the day Fuller was killed.

Smith had testified on Monday that he and Turner were together, but he was far less certain of the details and time than Turner. Six of the 10 accused have presented alibis. The attorney for Steven Webb, 20, rested his case yesterday after a neighbor testified Webb had an "excellent reputation" in the community for "peacefulness." Attorneys for two other defendants rested their cases without presenting any witnesses, and one defendant, Clifton Yarborough, 17, has yet to present his defense.

Several prosecution witnesses testified that Turner was present when Fuller was killed and that he participated in her beating.

During his cross-examination of Turner, Assistant U.S. Attorney Jeffrey Behm attempted to show that Turner remembered too many specifics of his account for it to be real, including the name of a record he had played the day of the killing and answering a phone call to Smith's sister from her boyfriend.

"You remember all these details very clearly . . . ," Behm told Turner. "When you were arrested you had your alibi ready."

Unlike their approach with most of the other defendants, prosecutors did not say yesterday that Turner's testimony was inconsistent with a statement he gave to police soon after his arrest.

Robert DeBarardinis, Turner's lawyer, smiled broadly as he left the courtroom and a number of defense lawyers commented on the smoothness of Turner's delivery.

During the past week, defense lawyers have been critical of the majority of the other alibis.

"He only helped himself," said one defense lawyer. "He was very good," said another, "he looked like a Rhodes scholar compared to the rest."

Turner told the jury he remembered the day clearly because Smith received a phone call telling him about the killing in the alley and the next day a family friend commented that it was lucky Smith was at home.

The police "would try to put Kelvin there," Turner recalled the woman saying.