"The gunman said they were doing this because somebody had killed their family and they didn't receive the death penalty and they should have."

That is the reason, Elsie Young testified yesterday, the Hanafi Muslims gave for taking her and 14 other persons hostage last March 9 at the District Building.

She then stepped from the witness stand and identified Abdul Muzikir, 22, also known as Marquette Anthony Hall, and Abdul Nuh, 28, also known as Mark E. Gibson, as the two men who had held her captive in a City Council office until she escaped about 7 p.m. on March 10.

She said Muzikir exchanged several shots with police who were in the main hallway of the fifth floor of the District Building and that at one time he turned and fired a blast into a room where the hostages were lying. She said the police fire knocked plaster from the wall of the room where she and the others were lying.

Muzikir and Nuh are two of 12 Hanafis on trial in D.C. Superior Court on charges of murder and kidnaping stemming from the takeover of the District Building and two other Washington locations - the international headquarters of B'nai B'rith, the Jewish service organization, and the Islamic Center.

The 12 are charged with these crimes in aid of an alleged conspiracy to force the government to turn over to them five Black Muslims convicted of murdering seven members of the family of Hamaas Abdul Khaalis, 55, alleged leader of the plot, in 1973. The Black Muslims all are serving multiple life sentences.

Young was the first witness from the District Building incident to testify that the hanafis there gave revenge for the 1973 murders as the motive for their action.

Numerous witnesses from the B'nai B'rith building and the Islamic Center have testified that they heard their captors speak of revenge.

The testimony of Mrs. Young, a receptionist at the City Council offices, was designed to advance the prosecution's conspiracy theory. Under this theory, all the defendants at all three sites are accused of acting for the same purposes. Thus, all are charged with murder in the death of Maurice Williams, a 24-year-old radio reporter who was cut down by a shotgun blast at the District Building.

In another development yesterday, prosecutors introduced into evidence fingerprints of Abdul Nuh that had been take from a knife found in a U-Haul van allegedly used by the Hanafis to transport a small arsenal of weapons and other equipment to the B'nai B'rith building.

Most of yesterday's session - the 22d day of court proceedings since the trial began May 31 - concerned the "chain of custody" of various physical exhibits. The purpose of this testimony is to determine whether any of the exhibits could have been altered from the time they first were seized and the time they are presented in court.

There was testimony about the custody of a shotgun pellet taken from the chest of City Council member Marion S. Barry Jr., who was wounded at the District Building, about pellets taken from the body of Williams, and about more pellets taken from the arm and back of Robert J. Pierce, 51, a City Council aide who was wounded.

Pierce allegedly was shot by Abdul Muzikir when Muzikir turned and fired a blast into the room where the hostages had been ordered to lie on the floor. Young said she saw him do this. She also said she saw him pump the action of his shotgun several times and reload the weapon.

About 7 p.m. March 10, about 28 hours after she had been taken prisoner, Young told the jury, Muzikir put down his shotgun. She said she then "got up and ran" to safety.

Dr. Robert John Neviaser, an orthopedic surgeon at George Washington University Hospital, told the jury of Pierce's present condition.

"Well, first of all he's alive," the doctor said. "Secondly, he's completely paralyzed from (the lower back) down to his toes and his right forearm and hand have no function at the present time."

In another development Abdul Rahman, 37, also known as Clyde Young, complained of pain in his left hip. Judge Nicholas S. Nunzio ordered him to attend the trial after testimony by a doctor at D.C. jail that Rahman was running a slight fever.