U.S. District Judge Royce C. Lamberth ordered White House lawyers to answer questions they previously refused in a lawsuit brought by the conservative legal group Judicial Watch, which has filed numerous suits against the Clinton administration.
"This court finds that the plaintiffs have presented facts that establish a criminal violation of the Privacy Act," Lamberth ruled.
Such a violation is a misdemeanor.
The judge, a Republican appointee, added that evidence in the case "established that the president had the requisite intent for committing a criminal violation of the Privacy Act" when he authorized the release of letters from former White House volunteer Kathleen Willey in the midst of the 1998 criminal investigation that led to his impeachment and acquittal.
At a White House news conference Wednesday, Mr. Clinton said he obviously did not agree with the judge's ruling. He said the letters from Willey were released "reluctantly'' because it was "the only way I knew to refute allegations against me that were untrue.''
The White House released the letters the morning after a 1998 TV appearance in which Willey alleged the president made an unwanted sexual advance next to the Oval Office in 1993.
Presidential aides used the letters to cast doubt on Willey's allegations, saying the letters showed she remained friendly with Mr. Clinton after the alleged incident. Mr. Clinton has denied any wrongdoing.
Lamberth's ruling comes in a lawsuit over the White House gathering of hundreds of FBI background files on Republican appointees. The judge allowed Judicial Watch wide latitude in exploring the issue of whether the White House routinely gathered and released damaging information about its political opponents.
As part of the discovery process, the group was allowed to ask extensive written questions about the release of the Willey letters even though Willey is not a party to the suit. Presidential aides refused to answer some of those questions, prompting Lamberth's ruling.
Lamberth held that the White House was informed by one of the judge's own rulings, nine months before the release of the Willey letters in 1998, that the White House was covered by the Privacy Act.
The White House maintains "that the president did not act willfully because the Department of Justice has, in the past, taken the position that the White House office is not subject to the Privacy Act," the judge noted.
"This court, however, has already rejected this argument in this same case," Lamberth added. "When the president and EOP (executive office of the president) released the letters they were fully aware of this court's ruling that the Privacy Act ws applicable and that the disclosure of the letters was therefore prohibited."
Lamberth said three top presidential aides Deputy Counsel Bruce Lindsey, former Counsel Charles F.C. Ruff and former Deputy Counsel Cheryl Mills engaged in discussions that led to the release of the letters.
The ruling notes the senior lawyers "had their discussions about whether the letters should be released" and "ultimately recommended their release to the president." Clinton "concurred in this recommendations," the judge said.
"The plaintiffs have established that the president committed a criminal violation of the Privacy Act," the judge ruled.
Lamberth rejected the White House claim that the three lawyers did not need to answer questions about the letters because of attorney-client privilege.
"The discussions regarding the release of the Willey letters, even if initially protected by the attorney-client privilege, fall squarely within the crime-fraud exception to this privilege," he ruled.
Lamberth's ruling simply clears the way for Judicial Watch to press the White House to answer additional questions about the Willey letters.
However, the Justice Department has an open investigation into another impeachment-related release of damaging information about a White House critic: the Pentagon's release of data from Linda Tripp's personnel file.
In grand jury testimony in August 1998, Mr. Clinton denied Willey's allegations and referred to the release of the letters, telling prosecutors: "You know what evidence was released after the 60 Minutes broadcast that I think pretty well shattered Kathleen Willey's credibility."
Mr. Clinton told the grand jury that he considered releasing the letters earlier, but "frankly, her husband had committed suicide. She apparently was out of money. And I thought, `Who knows how anybody would react under that?' So I didn't."
"But, now when 60 Minutes came with the story and everybody blew it up, I thought we would release it," he said.
"I didn't know the volume of contact that she had which undermined the story she has told. But I knew there was some of it," the president added.