A federal jury convicted D.C. Mayor Marion Barry yesterday on one charge of cocaine possession, acquitted him on a second and announced it was unable to reach a decision on the remaining 12 charges.

U.S. District Judge Thomas Penfield Jackson declared a mistrial on the deadlocked charges. The mixed verdict and rapid ruling brought an end to an emotional chapter in the city's history that brought out deep differences of opinion about the mayor's conduct and the actions of the government.

U.S. Attorney Jay B. Stephens, who entered the courtroom just after the jury returned the verdicts, said he would announce his decision on a possible retrial of the remaining counts on Sept. 17, when Jackson said he would hold a hearing on the case.

Jackson did not set a sentencing date for the single possession count, on which Barry could receive up to a year in prison. It is rare for a first-time offender to be sentenced to jail for cocaine possession.

Crowds of people jubilant about the verdict booed Stephens as he held a news conference on the steps of the U.S. District Courthouse yesterday evening. At times, Stephens was almost drowned out by the jeers of Barry supporters who celebrated nearby.

Barry was convicted of a count charging that he possessed cocaine between Nov. 7 and Nov. 10, 1989, at the Mayflower Hotel with Doris Crenshaw, an old friend from the civil rights movement.

He was acquitted of the charge that he possessed crack cocaine at the Frank D. Reeves Municipal Center on Sept. 7, 1988, after buying it from crack dealer Lydia Reid Pearson. The defense produced witnesses who said the mayor was not in the city building the morning that Pearson said she sold the drug to him.

During the trial, Barry attorney R. Kenneth Mundy admitted that his client occasionally had used drugs.

To convict or acquit, the jury had to be unanimous.

Among the 12 charges on which the jury deadlocked were those involving some of the most controversial aspects of the case: testimony by former D.C. employee Charles Lewis and former Barry girlfriend Hazel Diane "Rasheeda" Moore; the Ramada Inn incident of Dec. 22, 1988; and the videotaped FBI sting of Barry at the Vista Hotel on Jan. 18. Moore lured the mayor there, and he was shown smoking crack, then being arrested. The Vista sting, on which the jurors could not reach agreement, capped years of federal investigation of the mayor.

On returning home last night, foreman Edward P. Eagles declined to discuss the breakdown of the jury votes. "We reached the verdict we could," he said. "We couldn't come up with a consensus."

Eagles, a history teacher at St. Albans School for Boys, said the jury did not try to "sort out what the government's purposes were" in prosecuting Barry. "We tried to concentrate on the questions at hand," he said. "What I was interested in was counts, evidence."

Juror Johnnie Mae Hardeman, 61, said last night the panel was hopelessly split on the three perjury counts and divided 6 to 6 on the charge arising out of the Vista sting. Hardeman, of Northeast Washington, said she believed prosecutors had unfairly singled out Barry for prosecution, and she said she doubted the credibility of Lewis and Moore.

In the courtroom, as jury foreman Eagles read the two verdicts, Barry stood, nervously unbuttoning his coat. At the words "not guilty" on count three, Barry's face was impassive. When Eagles read "guilty" on count 12, the mayor looked down at the table. When he looked up again, his expression seemed mildly annoyed. A few moments later, Barry wept silently as he hugged supporters in the courtroom.

On his way out of the courtoom, Barry spotted D.C. police Detective Al Arrington, one of the lead investigators in the case.

"Arrington," Barry said, reaching out to shake the officer's hand. "See you next time."

"You never know," Arrington replied.

Barry left the courthouse by a side entrance, then walked around to the front of the courthouse accompanied by a horde of cameramen and reporters. He conferred on the courthouse steps with his press secretary, Lurma Rackley, who announced that Barry would have no comment until a 2 p.m. news conference today. Barry's wife, Effi, was not in the courtroom.

When U.S. Attorney Jay B. Stephens appeared later to make a statement on the courthouse steps, he was greeted by loud boos from Barry supporters, who almost drowned out his statement on the verdict.

Stephens said his office would reassess the Barry case to decide whether to retry it. As Assistant U.S. Attorneys Judith E. Retchin and Richard W. Roberts stood impassively on either side of him, Stephens defended his decision to take Barry to trial.

"Our job is to be prosecutors, and to present the evidence fairly and professionally," he said, adding that it would have been irresponsible to ignore persistent allegations of drug use by the mayor.

"The verdict today at least says publicly and officially to Mr. Barry that 'You must accept responsibility for that conduct,' " Stephens said.

The prosecutors and investigators who put together the case stood behind Stephens on the courthouse steps as he tried to answer questions before the rowdy crowd. FBI agent Ronald Stern shook his head slightly while D.C. Detective James Pawlik chuckled sadly.

Retchin, one of the two prosecutors, said, "And that's the home crowd," making a meek attempt at a smile.

Then the group swept through the U.S. marshals' office and down through a basement parking garage. They left the courthouse escorted by two federal police cars.

Later, Stephens said of the crowd's booing, "I wasn't stunned at all." He added that when the case went to the jury eight days ago, among the prosecution team "there was a sense of calm -- that we had done our job and done it professionally, and there was nothing else that we could do."

"We feel lucky," Mundy said as he accompanied Barry from the courthouse. Asked whether he was surprised by the verdict, Mundy said, "I'm too old to be surprised."

Within 30 minutes, supporters of the mayor were driving past the courthouse on Constitution Avenue NW to honk their car horns and shout their pleasure about the verdict.

The jury of nine women and three men returned the partial verdict eight days after starting their deliberations. Several jurors appeared tense as court clerk Bob West asked each of them whether they agreed with the verdicts. A few of them looked at Barry as they entered the room.

The jurors have been sequestered since June 18.

In excusing the jury, Jackson departed from the usual tradition of judges' praising a panel's work, and he suggested he was not pleased with all of them. "I do want to thank you," the judge said. "I realize it has been something of a hardship for you. And I realize that you have, or at least some of you have, endeavored diligently to try to reach a verdict."

As the jury left the courtroom, at least one of the jurors, Joseph Deoudes, let out a celebratory whoop that echoed to the back of the room.

Barry was charged with 14 distinct crimes: 10 counts of possessing cocaine, three counts of perjury and one count of conspiracy to possess cocaine.

The verdict was immediately hailed as a major victory for Barry. Without a felony perjury conviction and the near-automatic prison sentence, there would be no legal obstacle to Barry's holding public office in the future.

On the other hand, those close to Stephens said the government had won two key victories. For one, they said, Barry dropped out of the mayor's race even before the trial began. And second, Mundy conceded at the close of the trial that Barry had been an "occasional" user of cocaine.

Although Barry dropped out of the mayor's race, close associates of the mayor have said that Barry could decide over the weekend to seek an at-large D.C. Council seat as an independent. The deadline for declaring himself as an independent is Monday. Even Barry's closest friends and political advisers have said they are amazed at Barry's ability to maintain a significant amount of popular support in the face of a two-month trial that has included allegations of his frequent cocaine use, questionable decisions about city contracts and one claim that he forcibly had sex with a Virgin Islands woman.

A four-year term on the council, where Barry served before his election as mayor in 1978, would afford him the opportunity to preserve his D.C. government pension, as well as a platform to influence city policy, which he has said he hopes to do.

At the same time, many Democratic Party activists and members of Barry's inner circle believe he is unlikely to reverse his June 13 announcement against seeking a fourth term. Party leaders said Barry's image was so damaged citywide by trial testimony about illegal drug use and extramarital affairs that even if he harbored ambition to run again for mayor, he almost certainly would not.

Barry's defense team fought the charge involving Pearson more vigorously than any other, asserting that Barry had an alibi for the morning of Sept. 7, 1988. In Barry's defense case, several witnesses -- including D.C. Fire Chief Ray Alfred -- testified that Barry was elsewhere that morning. The government argued that Barry had time that morning to go to the Reeves center.

By deduction, Mundy argued to the jury, the government's entire set of possession charges had not been proved because of the doubt he said the defense had cast on Pearson's allegations, which he called the "most specific" in the case.

The charge on which Barry was convicted was based on testimony from Crenshaw, a Montgomery, Ala., businesswoman. Crenshaw told the jurors that she used cocaine with Barry at the hotel, although she was unable to testify about the precise date. In his instructions to the jury, Jackson told them that the prosecutors need not prove that the possession occurred on an exact date for them to find Barry guilty.

Courtroom observers said Crenshaw's testimony seemed to be credible partly because of her civil rights credentials, and partly because she appeared to be a reluctant witness.

The most serious of the 14 charges were the three perjury counts, for which a conviction carries a near-certain prison sentence. All the perjury charges were based on Barry's testimony before a federal grand jury in January 1989. During his testimony, Barry told the grand jurors that he was not aware Lewis was involved with drugs, that he had not given drugs to Lewis and that he had not received drugs from Lewis.

Barry was subpoenaed to appear before the grand jury after U.S. Attorney Stephens decided to investigate the Ramada Inn episode of Dec. 22, 1988, in which D.C. police broke off an investigation of drugs at the hotel when they learned Barry was visiting suspect Lewis in Lewis's room.

To prove Barry lied about his knowledge of Lewis's drug involvement, prosecutors opened their case with a long examination of Lewis, who told of using drugs with Barry at the Ramada in December 1988 and in the Virgin Islands earlier that year and in 1986.

Mundy countered with a blistering attack on Lewis, eliciting in cross-examination that Lewis had spent dozens of hours with D.C. police and FBI agents in preparation for his court appearance. Mundy also used his cross-examination of Lewis to make a point for the jury, that a conviction on perjury would mean a prison sentence for Barry.

The longest testimony came from Moore, a former Barry girlfriend-turned FBI informer. Moore, recalling her two years in an intimate relationship with the mayor between 1986 and 1988, told the jurors that she had used cocaine and crack with Barry more than 100 times since June 1986. She described Barry's paranoid-seeming behavior after using drugs: Sometimes he was convinced he was being watched from afar. Moore described how, on separate occasions, both she and Barry almost overdosed on crack.

On cross-examination, Moore conceded that she may have gone too far in arranging the sting by insisting that Barry come to her room at the Vista, but she maintained that she was justified in asking Barry seven times if he wanted to use cocaine. Mundy maintained that, except for the last time, Barry rejected each suggestion that he use drugs. Moore insisted that it was Barry who brought up the subject of drugs moments after he arrived at the hotel, when he asked "You been good? Of course not."

It was not clear until just before 6 p.m. whether there would be a verdict. The jury sent a note to Jackson in mid-afternoon, asking that they be allowed to deliberate until 6:30 p.m., and several lawyers and courthouse workers took the message as a sign the jurors could be close to an agreement.

Just before 5 p.m., foreman Eagles sent a second note to Jackson, asking "if on any count the jury is unable to reach a verdict, what are our instructions?"

Jackson brought the jury into the courtroom and handed them five written questions, asking them to go back into the jury room and return with written answers. In his note, the judge asked whether the jury had reached a verdict on any of the counts, whether they wanted to announce the partial verdict, whether any further deliberation would enable them to reach agreement on any remaining counts and whether they wished to deliberate further yesterday or today.

After the jury returned to the courtroom and announced the two verdicts, Jackson delivered a last-resort instruction designed to encourage a deadlocked jury to deliberate further. After a few moments back in the jury room, the jurors returned and said that additonal deliberation would be of no use.

Following are the 14 charges against D.C. Mayor Marion Barry and a listing of key witnesses.

COUNT 1

Hung Jury

Conspiracy to possess cocaine, Fall 1984 to Jan. 18, 1990.

This charge is based on testimony of witnesses in counts 2 to 14 and on logs of telephone calls made by alleged co-conspirators and Mayor Marion Barry.

COUNT 2

Hung Jury

Possession of cocaine, November 1987.

This charge is based on testimony of Barry girlfriend Theresa Southerland and Georgetown restaurateur Hassan H. Mohammadi.

COUNT 3

Not Guilty

Possession of crack cocaine, Sept. 7, 1988.

Lydia Reid Pearson's testimony provided the basis for this charge.

COUNT 4

Hung Jury

Possession of crack cocaine, Dec. 16, 1988.

Counts 4 through 7 refer to testimony by Charles Lewis that he and Barry used drugs together at the downtown Ramada Inn.

COUNT 5

Hung Jury

Possession of crack cocaine, Dec. 17, 1988.

COUNT 6

Hung Jury

Possession of crack cocaine, Dec. 19, 1988.

COUNT 7

Hung Jury

Possession of crack cocaine, Dec. 22, 1988.

COUNT 8

Hung Jury

Perjury.

This charge centers on Barry's denial in January 1989 grand jury testimony that he knew about Lewis's involvement with drugs.

COUNT 9

Hung Jury

Perjury.

This charge centers on Barry's denial in grand jury testimony that he ever gave Lewis any drugs.

COUNT 10

Hung Jury

Perjury.

This charge centers on Barry's denial in grand jury testimony that he ever received any drugs from Lewis at the Ramada.

COUNT 11

Hung Jury

Possession of cocaine, Aug. 26, 1989.

Testimony by Barry friend and former D.C. employee Darrell Sabbs was key to this charge.

COUNT 12

Guilty

Possession of cocaine between Nov. 7 and Nov. 10, 1989.

This was based on Barry associate Doris Crenshaw's testimony that she used cocaine with him at the Mayflower Hotel.

COUNT 13

Hung Jury

Possession of cocaine between Jan. 1 and Jan. 18, 1989.

Barry friend Bettye L. Smith said she gave him cocaine and used drugs with him during this period.

COUNT 14

Hung Jury

Possession of crack cocaine, Jan. 18, 1990.

This charge stems from the FBI sting operation involving Hazel Diane "Rasheeda" Moore at the Vista Hotel.

Staff writers Michael Abramowitz, John Ward Anderson, Jenice Armstrong, Karlyn Barker, Tom Bell, Valerie Chow Bush, Ruben Castaneda, Bill Dedman, Sharon Epperson, Gabriel Escobar, Steven C. Fehr, Marcia Slacum Greene, Stephanie Griffith, Retha Hill, Kent Jenkins Jr., Beth Kaiman, Joe Kirby, Nancy Lewis, Brooke Masters, R.H. Melton, Eugene L. Meyer, Jill Nelson, Daniel H. Pink, Lynda Richardson, Carlos Sanchez, Rene Sanchez, Chris Spolar and researchers Ben Iannotta and Matthew Lee contributed to these reports.