Defense attorneys for Brian Lee Tribble called their first witness yesterday and her testimony raised questions about whether Len Bias might have provided the cocaine that he and friends used in the hours before his death last June.

Sherrie Hursey of Northeast Washington testified that she was at Tribble's apartment north of the University of Maryland's College Park campus when Bias arrived about 12:30 a.m. June 19. Hursey, who said she had dated Tribble occasionally, said she saw Bias in Tribble's living room when she unknowingly sat on Bias' carry bag.

"He said to get off of his pouch," Hursey testified. "He seemed sort of anxious to get it."

About 1 a.m., Hursey said, she left the apartment with Tribble and Bias, both of whom took her home in Bias' Nissan 300ZX. Hersey said Bias was driving far above the speed limit. "I would say about 70 to 80 mph," she testified.

Bias and Tribble left her home about 1:45 a.m., Hursey said. Hursey's name had not surfaced previously in the case, but several persons at the apartment said a woman had left with Bias and Tribble.

Tribble, 24, of Northeast Washington is on trial in Prince George's Circuit Court on charges of distributing cocaine, possessing cocaine with intent to distribute it, possessing cocaine, and conspiracy to distribute cocaine stemming from Bias' death. If convicted, he faces a maximum of 20 years in prison and a $25,000 fine.

Thomas C. Morrow and Ava Lias, Tribble's attorneys, tried last week through cross-examination of some of the 16 prosecution witnesses to show that doubt exists about who supplied the cocaine for the early-morning celebration in Bias' dormitory suite that ended with Bias unconscious on the floor.

Tribble, Bias and his teammates Terry Long and David Gregg snorted the drug for about four hours that morning, according to testimony.

Long and Gregg, key witnesses for the prosecution, testified last week that they did not know whether Tribble or Bias brought the cocaine into the Washington Hall dormitory suite.

The prosecution has alleged that Tribble or Tribble and Bias conspired to supply the cocaine for a party to celebrate Bias' selection in the college draft two days earlier by the National Basketball Association's Boston Celtics.

Prosecutors said that Tribble took cocaine from the room after Bias collapsed and put it in Bias' Nissan 300ZX, which Tribble drove to Leland Memorial Hospital, where paramedics had taken Bias.

Johnnie Walker Jr., a D.C. police officer and Bias family friend, testified yesterday that he searched Bias' car hours after Bias died to retrieve Bias' property, particularly a Louis Vuitton bag in which Bias carried money and personal papers.

Walker said he spotted the car in front of Cole Field House at the university; he said the car was unlocked, with the removable roof panels off and the windows down. Walker testified that he looked in the glove compartment, under the floor mats, beneath the seats and in the console for Bias' bag.

Walker, a two-year member of the D.C. police department, said he did not see any cocaine in the car.

The next day, a University of Maryland police officer reported finding about nine grams of cocaine behind the dashboard on the passenger side of Bias' car and about two grams on the floor of the passenger side.

As its third witness, the defense called James Wiseman, the state's attorney's office investigator who worked on the Tribble case.

But after a 20-minute bench conference involving attorneys and Judge James M. Rea, it was decided that Wiseman would not testify.

The defense might end its case today. It is unclear whether Tribble will testify.