"The machete man" was tying him up on the floor outside the office of D.C. City Council Chairman Sterling Tucker, said John P. Austin, when "the gunman" fired a shotgun blast at the doorway where Mack W. Cantrell was standing.

"I saw that man whirl as the door opened and fire that shotgun," Austin told a D.C. Superior Court jury yesterday. "I saw Cantrell in the foorway."

He said Cantrell "screamed" when the shot was fired.

"There was an awful lot of confusion," said Austin who, like Cantrell, is a guard at the District Building. "People were screaming, I was screaming. I was scared, too."

Austin then identified "the gunman" as Marquette Anthony Hall, and "the machete man" as Abdul Nuh, 28, also known as Mark E. Gibson.

With Austin's testimony, the prosecution began to close in on the central part of a case in which 12 Hanafi Muslims are charged with murder and armed kidnaping in the taking of 149 hostages last March at the District Building, at the international headquarters of B'nai B'rith, the Jewish service organization, and at the Islamic Center.

According to the government's evidence, Cantrell and D.C. City Council member Marion S. Barry Jr. were wounded by the shotgun blast allegedly fired by Muzikir, and Maurice Williams, 24, a reporter for radio station WHUR, was killed by it.

Austin, the first person taken hostage at the District Building, was the first witness to describe what happened in the area where the hostages were held and the first to identify Muzikir as the trigger man responsible for the woundings and the slaying.

Muzikir, a slightly built man, is charged with first-degree murder in Williams' death. He and the other 11 defendants also are charged with felony murder in the first degree under the theory that all were acting as part of a conspiracy in the takeover of the three buildings.

The purpose of the conspiracy, according to the government, was to compel officials to turn over five Black Muslims convicted of murdering seven members of the family of Hamaas Abdul Khaalis, 55, alleged leader of the plot. Khaalis maintained during the sieges that the Black Muslims, all of whom are serving multiple life sentences, were not properly punished.

Besides Barry and Cantrell, Robert J. Pierce, a retired State Department official who was working as a City Council aide, also was wounded by gunfire at the District Building. Wesley A. Hymes was shot and wounded at the B'nai B'rith headquarters and several other persons were stabbed or beaten during the takeovers, which extended March 9 to March 11.

But the heart of the government's effort is to convict all 12 Hanafis of felony murder in the first degree in the slaying of Williams.

Austin's testimony came on a day when Judge Nicholas S. Nunzio granted defense motions to suppress in-court identifications of Muzikir and Nuh by two other government witnesses.

One of those withnesses was D. C. special police officer James A. Yancey Jr., a District Building guard who said he was standing next to Cantrell at the moment the latter was shot.

On Monday, Yancey testified that he had caught a glimse of the gunman when Cantrell opened the door from the fifth floor corridor of the District Building to the area where City Council members have their offices.

The jury was sent from the courtroom so he could be examined on whether this glimpse had provided a good enough look at the gunman to permit an identification in the presence of the jury. When Yancey testified that he had seen a picture of Muzikir in a newspaper, Judge Nunzio ruled that this may have influenced him to such a degree that his identification must be ruled out.

Although all of yesterday's session was devoted to the murder of Williamss and the events surrounding it, the atmosphere inthe courtroom was noticeably less tense than it has been in recent days.

On Monday, it was learned that Nunzio had cited three of the 12 defense attorneys in the case for contempt of court for arguing with his rulings. Several of the lawyers planned to ask the judge to excuse them from the case as a result of the disciplinings, but these moves were abandoned yesterday.

Nunzio complimented the lawyers on their conduct yesterday.

"I recognoze that you are doing a job zealously," he said. "I recognize that the issue of murder is now before the court. This court has not jumped on anyone." He added that "I'm not an ogre."

Austin's testimony followed that of Dr. William J. Brownlee Jr., deputy D.C. medical examiner, who said Williams had died of five wounds caused by buckshot. It also followed the testimony of Lovett Johnson, a building engineer at the District Building, who said he had walked into the corridor after hearing a shot and found Williams dead and Cantrell wounded and no one else in sight.

Austin said he had just stepped off an elevator and was going to buy a soft drink from a machine in a stairwell when the first saw the Hanafis, whom he referred to throughout his testimony as "the machete man" and "the gunman."

He said "the gunman," who was holding a shotgun under a piece of clothing with about four inches of barrel protruding, said to him, "I got your ass now, Mr. Policemen."

"I was shocked," said Austin, who was unarmed at the time. "I just looked at him and he just looked at me. We just stared at each other."

Then, he said, "the gunman" ordered him through the door to the area of Council Chairman Tucker's office. (Tucker was not present during the siege).

Austin said he saw it was a 12 gauge shotgun when "the gunman laid it on my nose and brought it down tomy chin."