WASHINGTON--A former top assistant to onetime Housing Secretary Samuel R. Pierce Jr. cited his Fifth Amendment rights today in refusing to answer "substantive" questions by a congressional panel about the scandals at HUD.

Lance Wilson, once Pierce's executive assistant, appeared under subpoena but refused to answer most questions.

That means Pierce and his two closest aides at HUD--Wilson and his successor as executive assistant, Deborah Gore Dean--have all refused to respond to questions by the House subcommittee probing allegations of influence-peddling, fraud and mismanagement at the Department of Housing and Urban Development.

Wilson read a brief statement saying "statements made by the subcommittee members...convinced me the subcommittee had already prejudged me" and identified him as "a prime candidate for a criminal investigation."

Committee Chair Tom Lantos (D-Calif.) then posed a series of four questions to Wilson, who refused to answer each one.

Although Wilson said he would answer no "substantive" questions, he later responded to two questions put to him by Rep. Christopher Shays (R-Conn.).

Shays asked if the HUD inspector general, who earlier this year released a report finding widespread problems in the department's moderate rehabilitation housing subsidy program, had sought to talk to him about that program, and if Wilson had done so.

Wilson responded that he had been asked to meet with the inspector general, but did not do so. Asked to explain why he did not meet with the inspector general, Wilson refused to answer.

Outside the courtroom, Wilson's attorney Raymond Banoun charged that members of the subcommittee were trying to "grandstand" and had spent much of the meeting "ridiculing someone for exercising his rights."

"They don't want to know the truth," Banoun said.

As Pierce had done a day earlier, Wilson used a House rule to bar television, radio and photographic coverage of his appearance.

The panel also planned today to question Donald Maron, chief executive officer of Paine Webber, about the company's dealings with HUD. Wilson went to work for Paine Webber after leaving HUD and helped the company obtain HUD business.

Pierce, in a dramatic session Tuesday, appeared under order of subpoena before the House Government Operations subcommittee on employment and housing.

Lantos and other committee members responded today to Pierce's charge that he had been "prejudged" by the panel.

Lantos said the panel has not prejudged Pierce's potential criminal culpability but had reached a judgment about his tenure as secretary of HUD for eight years.