A Bladensburg man and a Miami man were convicted yesterday by a federal jury here of heroin distribution conspiracy in connection with a scheme to buy five kilograms of heroin from an undercover D.C. police officer.

Five persons were on trial charged with heroin distribution conspiracy; two were convicted of the conspiracy count, two persons were found not guilty of that charge but convicted of a firearms charge, and one man was acquitted on all counts.

The verdict, reached after about six hours of deliberation, came about the same time the brother of Sharon S. Jones, a defendant in the case, surrendered to federal authorities who had been searching for him since Wednesday when he was charged with jury tampering.

Sharon Jones, 31, of 101 Ridge Rd. SE, her former boyfriend Robert L. Bullock, 35, of 1617 Ridge Place SE, and Miamian Frank E. Goa, 38, were acquitted of the heroin distribution conspiracy charges.

Jones and Bullock were convicted of federal firearms charges, and U.S. District Judge Joyce Hens Green ordered Sharon Jones held without bond until sentencing on Jan. 20.

Bullock, Steve Fafowora, 38, of Miami, and Olufonso A. Yussef, 29, of 5800 Annapolis Rd., Bladensburg, have been jailed since their arrest in July. Fafowora was also convicted of racketeering, and Green will rule on what assets he must forfeit.

U.S. Magistrate Jean F. Dwyer ordered Timothy S. Jones, 25, also of 101 Ridge Rd. SE, held without bond on the jury tampering charge, which was lodged after a juror deliberating in the case testified that Timothy Jones had followed her home and offered to give her anything to learn the outcome of the jury's first session.

Dwyer set a preliminary hearing on the matter for Thursday.

The drug case against Fafowora and the four other defendants stemmed from three months of negotiations between D.C. Detective Dwight Rawls, who is detailed to a federal Nigerian drug task force, and Fafowora for a deal involving five kilograms of heroin.

Fafowora and Yussef were arrested at the Channel Inn in Southwest Washington on July 6 after they gave Rawls $39,000 and the deeds to two Miami properties in exchange for 1.5 kilograms of heroin.

Testimony during the four-week trial showed that Jones and Bullock were acting as lookouts for the transaction and were arrested in a car outside the hotel with two loaded guns.

Assistant U.S. Attorney Paul L. Knight, who prosecuted the case, said in court yesterday that Jones had bought two .357 Magnum handguns using false Virginia identification papers and that only one was recovered at the time of her arrest.