FBI CONFIRMS IT HAS LEWINSKY DRESS; TESTING MAY FOLLOW.

Byline: Frank Greve, Angie Cannon and Raja Mishra Knight Ridder Newspapers

Independent Counsel Kenneth Starr on Thursday asked the FBI to test a dress his prosecutors obtained from Monica Lewinsky to determine if it contains evidence of a sexual encounter with President Clinton.

``We have the dress in our possession,'' an FBI spokeswoman said.

A lawyer familiar with the case, speaking on the condition of anonymity, said Lewinsky told Starr the garment might be stained with semen.

Dismissed once as entirely too salacious to be believed, the tale of Lewinsky's dress gained new currency Thursday, providing new evidence for Starr and creating further troubles for Clinton.

Lewinsky also turned over tapes that contain telephone messages from the president, the lawyer said.

The dress and tapes were offered as part of a deal that gives Lewinsky full immunity from prosecution in exchange for her grand jury testimony. Lewinsky, lawyers close to the investigation say, will testify that she and Clinton did have a sexual affair. Starr is investigating whether Clinton perjured himself when he denied any sexual relationship with the former White House intern and whether the president or any of his associates encouraged her to lie about it under oath.

The dress could provide ``powerful'' physical evidence about the existence of an affair, legal experts said. Technicians would be looking for DNA, which is something like a genetic fingerprint in human cells.

Word of the dress's existence came shortly after Clinton lawyer David Kendall announced Wednesday that the president would submit to questions from Starr's prosecutors on Aug. 17. Clinton will answer questions under oath in the White House on videotape with his lawyers at his side.

Need sample

But Starr might be after more than just Clinton's testimony. If technicians find evidence of semen on Lewinsky's dress, prosecutors would need a sample of Clinton's DNA for comparison.

Experts said that if Clinton voluntarily provides a blood sample, the entire DNA matching process could be completed within 10 days.

Kendall did not respond immediately to a phone message left by Knight Ridder asking whether his client would cooperate with a DNA test. White House spokesman James Kennedy would not comment.

Lawyers familiar with Lewinsky's account have said she is prepared to testify that she and the president had a sexual relationship and talked about ways of hiding it. A lawyer familiar with Lewinsky's account said she has told prosecutors that she and the president discussed the possibility of returning gifts Clinton had given her.

Rumors of a dress first surfaced early in the Lewinsky investigation but were quickly tamped down by William Ginsburg, then Lewinsky's lawyer. But another lawyer said on Thursday that Lewinsky had discussed the existence of the dress with her former friend Linda Tripp, who recorded Lewinsky's conversations about the president on tape.

The lawyer, who is familiar with Tripp's account, said Lewinsky showed Tripp the dress last fall and told her it had been stained during sex with Clinton.

Evidence experts said Starr would have to find Clinton's DNA intermingled with Lewinsky's in order to definitively prove they had engaged in sex.

If the dress contains only the president's DNA, then several possible scenarios could be argued.

``If it's just his semen, his lawyers could make the `heavy petting' argument'' and say that sex never happened, said Walter Rowe, a forensics professor at George Washington University.

A key factor in finding evidence would be the condition of the dress. One lawyer close to the investigation said the dress had been in the possession of Lewinsky's mother, Marcia Lewis.

Experts said that if the dress were stored in an air-conditioned area, such as an apartment, then the DNA sample would be very much intact.

``DNA is fairly stable stuff. If it's in someone's closet, even for years and years, it's not a problem,'' said Jay Siegel, a criminal science professor at Michigan State University.

Damp conditions, prolonged exposure to sunlight and repeated washings could degrade DNA enough to render it useless to prosecutors. Bacteria grow in damp conditions and would destroy the semen stain. And if Lewinsky or her mother washed the dress several times or dry-cleaned frequently, any DNA could be gone.Otherwise DNA, especially from semen, is considered a very strong piece of evidence, experts said. ``Most prosecutors, if they get DNA, will say it's a slam-dunk case,'' Rowe said.

Why save the dress?

The existence of a stained dress also raises the question of why any young woman would keep such an item.

Saving every possible souvenir from an encounter with an idolized person is not unusual, says Dr. Lonnie Barbach, a psychologist and sex therapist practicing in Mill Valley.

``It doesn't have to be a sexual thing,'' continued Barbach, who has no specific knowledge of Lewinsky or her case. ``You save a lock of hair or voice-mail message from an idolized person. Every present, everything the idolized person has written to you is saved and precious.''