In the end, as in the beginning, prosecutors did not have a case against Brian Lee Tribble proving that he supplied the cocaine that killed University of Maryland basketball star Len Bias June 19.

What the prosecution did have was a mound of cocaine that caused the tragic death of a nationally known 22-year-old All-America athlete. That event drew increased nationwide attention to the problem of drug abuse, threw the Maryland athletic program into turmoil, and led to criminal charges brought by the then-Prince George's County state's attorney who was fighting for his political life during a heated election campaign.

But what police and prosecutors never had -- according to jurors and police sources -- was convincing evidence to prove that Bias' close friend Tribble was the source of the cocaine for the early-morning party in a campus dormitory. The party began as a celebration of Bias' selection by the Boston Celtics, but ended when the 6-foot 8-inch Bias fell to the floor in cocaine-induced convulsions.

"All we know is that it was an evening of celebration," said juror Doris E. Walker of Suitland. "They were all friends, and this tragedy took place, when all of them were there. But no one knew how cocaine got in the room. I couldn't blame Tribble."

That was the view of 12 Prince George's County Circuit Court jurors who deliberated six hours before acquitting Tribble late Wednesday. That was also the view of some key Prince George's police investigators, who privately acknowledged the weakness of the Tribble case nearly a year ago and predicted his acquittal.

"If it hadn't been Len Bias, the case never would have gone to trial," said one officer familiar with the investigation. "I think we did what the public wanted, and that was to try to find the source of the drugs that killed Len Bias."

Police believed that they had found the source in Tribble, a 24-year-old former Maryland student who drove a Mercedes-Benz. But police also were well aware that their circumstantial case against him would be difficult to prove, the police source said.

Almost immediately after Bias' death, Tribble became the focus of the investigation into what police termed "a suspicious death." Then-State's Attorney Arthur A. (Bud) Marshall Jr., during his reelection campaign, stood on the steps of the county courthouse surrounded by hundreds of local and national news reporters and said that he believed Tribble had supplied the cocaine.

Marshall's handling of the grand jury investigation spurred criticism from some persons who said he was using Bias' death to get free publicity in his tough Democratic primary election battle against Alex Williams, who criticized Marshall's behavior, called for a state investigation of Marshall's handling of the grand jury -- and defeated him.

Even yesterday, the two men continued to spar about the Tribble case. The day after the jury's verdict, Marshall and Williams said each other's administration might be part of the reason Tribble was acquitted.

"I think everyone has tired of this," said Williams, who yesterday dismissed two obstruction of justice charges pending against Tribble.

Williams said that memories of last summer's grand jury proceedings, with hordes of television crews hounding witnesses, and Marshall's numerous public statements might have influenced the outcome of the case. "I think quite possibly that might have been in the back of folks' minds" when the jury deliberated, Williams said. "I am sure that it was considered."

Marshall, who left office in January, said he did not know much about the prosecution's case against Tribble, including surprise witness Terrence Anthony Moore and Bias' alleged role as a co-conspirator in Tribble's alleged drug network.

Moore, 17, who had an extensive juvenile criminal record, testified that he sold cocaine for Tribble. But jurors said after the verdict they did not consider him a credible witness.

Bias was described by prosecutors as a "courtesy middleman" who had conveyed drugs from Tribble to other users, including his teammates Terry Long and David Gregg, who partied with him that night. Long and Gregg were indicted on drug possession charges, which were later dropped in exchange for their testimony.

"We had no indication that Bias supplied drugs to Long and Gregg," Marshall said. "I was not aware of what Moore or anyone else had to say about Bias. I don't know if it was overkill, but their case may have suffered because of {Moore's} lack of credibility. We thought we could certainly get a conviction for possession of cocaine."

But the jury deciding Tribble's fate did not think so.

Tribble was charged with distributing cocaine, possessing cocaine with intent to distribute it, conspiracy to distribute and possess cocaine and possessing cocaine. The jury dispensed with all but the possession charge within a couple of hours, jurors said.

The jurors were not convinced that cocaine found by university police in a trash dumpster behind Bias' dormitory was the same cocaine that Bias, Tribble, Long and Gregg snorted from about 2:30 to 6 a.m. June 19. And they were not convinced that 11 grams of high-quality cocaine found in Bias' leased Nissan 300ZX the day after his death was the same cocaine that was in the room that morning.

"If the paramedics had put their hands in {the cocaine in the room}, that would have made a difference," said jury foreman Douglas R. Wilson.

The jury gave little credence to the prosecution's theory: that Tribble, Bias and Terrence Moore were co-conspirators in Tribble's alleged cocaine distribution network.

Moore's testimony was crucial to prove the theory. Moore testified that he sold up to 100 half-gram packages of cocaine a day for Tribble around Montana Avenue in Northeast Washington and frequently spotted Bias in that area known for drug sales. But his testimony was considered unbelievable, jurors said.

Thomas C. Morrow, Tribble's attorney, cross-examined Moore for almost an hour, with most of his questions leading Moore to recite his seven years of involvement with Maryland's criminal justice system.

Juror Doris Walker said she found it hard to believe that Bias, whose face was well-known from newspaper articles and televised Terrapins' games, would hang around a known drug market, as Moore claimed.

Testimony from Long and Gregg -- which then-state's attorney Marshall thought would be enough to convict Tribble of possessing cocaine -- was not given as much significance by the jury because much of it was not corroborated by other witnesses, as is required for a drug conviction under Maryland law.

"There was no corroboration of Long's and Gregg's testimony," said Wilson, the jury foreman. "Therefore there was no Long and Gregg."

The state's theory led prosecutors to try to debase Bias' reputation as a clean-living born-again Christian whose family, friends and coaches scoffed at the idea that he used drugs.

"There were a lot of things said about Brian and Len in the last year," said Brian Tribble's mother, Loretta, immediately after the verdict. "Len did drugs, but that doesn't make him a bad person. We want to put this all behind us."

So does the University of Maryland, whose reputation took as bad a beating as did Len Bias'. Vice Chancellor A.H. (Bud) Edwards said the verdict puts the Bias case to rest.

"We think the legal system has done its job, and it's over," Edwards said.

Staff writers Retha Hill, Sue Anne Pressley and Douglas Stevenson contributed to this report.