Dress May Yield Strong Evidence
Washington Post Staff Writers
Saturday, August 1, 1998; Page A11
In a room tucked away on the third floor of the J. Edgar Hoover Building, the concrete Pennsylvania Avenue fortress that serves as FBI headquarters, several waist-high examining tables covered with plexiglass hoods sit on an antiseptic linoleum floor.
Most often, it is used by the agency's lab examiners to assist on District criminal cases. Yesterday, the room where the FBI conducts DNA tests on semen was the likely first stop for the dress Monica S. Lewinsky has turned over to independent counsel Kenneth W. Starr. Starr in turn gave it to the FBI lab, which would be able to gauge with virtual certainty whether even a tiny sample of any genetic material on the dress can be traced to President Clinton, experts said.
Clinton has vigorously denied under oath any sexual relationship with Lewinsky, while Lewinsky has reportedly agreed to testify that she had an affair with the president. But DNA evidence has a way of resolving he-said-she-said stalemates. If the FBI were to identify Clinton's semen on the dress, Starr would have physical evidence that could help prove perjury by the president.
On the other hand, if examiners find no trace of the president's DNA, the Clinton camp would surely trumpet the finding as proof that Lewinsky's story is false, undermining Starr's investigation. The analysis could take a few days, experts said, or more than a month.
"The first question, of course, is whether there's anything on the dress," said geneticist Michael Baird, vice president of laboratory operations at Lifecodes, a Connecticut biotech firm that specializes in DNA testing. "But if there is something there, the technology has really advanced quite a bit. It's reached the point where it's possible to get a real DNA fingerprint, something that scientists would consider unique."
FBI officials refused to comment on the dress, but by now, specialists said, the bureau may well have determined whether there is semen or other biological material on it through chemical and microscopic analysis. If there is, Starr would presumably seek a DNA sample from Clinton either from blood, hair or a cell sample from inside his cheek. Only then could the FBI test for a possible DNA match.
The reliability of DNA testing was hotly debated in legal and scientific circles until the mid-1990s, but today just about every expert agrees that "DNA fingerprinting" can definitively determine whether a sample of genetic material was left by a suspect and whether it wasn't. The process uses enzymes and radiation to extract DNA from the cells where it resides and expose its individual patterns of genetic code. Unless a person has an identical twin, his DNA is unique.
It has only been 12 years since DNA analysis first appeared in court, when Lifecodes helped send a Florida rapist to prison, but the FBI says its laboratory alone has now tested genetic material in more than 12,000 cases in about one fourth of them, it has exonerated the suspect. In 1986, there were two DNA labs nationwide. Today there are more than 150.
In recent months, the FBI has argued that high-quality DNA matches should now be presented in court as matters of "scientific certainty" rather than high probability, and state-run laboratories are now deciding whether to follow suit. Any two randomly chosen people should have about 3 million differences between their DNA, experts said.
But it is not always easy to isolate a high-quality DNA sample. For example, fresh samples are a bit easier to test than old samples, although 44-year-old DNA evidence was used by the family of Sam Sheppard last year to assert his innocence in the murder that inspired "The Fugitive."
The condition of the sample is much more important than its age, the experts said. If Lewinsky kept her dress in a dry closet, for example, there should be no problem testing for semen, the experts said. If she kept it in a plastic bag, bacteria may have contaminated the sample. And if she washed or dry-cleaned the dress, the DNA analysis may be even more difficult.
The size of the sample has become less important as technology has advanced, and DNA analysis can now produce matches from cell samples invisible to the naked eye. The FBI lab has been shifting resources toward this new method, which also could produce results much faster, in a matter of days as opposed to several weeks.
"The advances in the technology are just amazing," said Mark Stolorow, director of operations for Cellmark Diagnostics, a Maryland firm that did DNA analysis in the O.J. Simpson, Unabomber and Jon-Benet Ramsey cases. "If a sample doesn't match, you can conclude with 100 percent certainty that it didn't come from the suspect. If a sample does match, the chances are going to be a million-to-one or much less that it didn't come from the suspect."
In fact, the odds of a mismatch are often calculated at even less than a billion to one. In the Simpson case, a team of high-priced defense attorneys persuaded a jury to disregard a damning trail of DNA evidence. But those attorneys, notably Barry C. Scheck, did not question the validity of "DNA fingerprinting" that placed Simpson's blood at the scene of the crime and identified Nicole Brown Simpson's blood on his socks. They simply argued that the blood samples were planted by the Los Angeles Police Department, an argument that would be fairly implausible in a case involving semen.
"It's very hard to explain how sperm gets on a garment," Scheck said. "It's hard to cross-contaminate unless you have other sperm to put on there. Where else would you get his sperm?"
The DNA section of the FBI laboratory was not a target of a 1997 Justice Department report that criticized unscientific practices and prosecutorial bias in three other sections of the once-vaunted lab. If the lab's examiners are able to test a decent sample from Lewinsky's dress, experts said, they should be able to say whether the sample is Clinton's. "It would match, or it wouldn't match," Stolorow said. "There isn't a lot of middle ground."
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