Rape Accuser Had Photo ID'd Possible DNA Match

DURHAM, N.C. -- A Duke lacrosse player whose DNA may match tissue found under the fake fingernails of an exotic dancer who claims she was raped was identified in a photo lineup with 90 percent certainty, sources tell NBC-17.

The Durham Herald-Sun reported Thursday tissue found under the accuser's acrylic fingernail came from the same genetic pool and was "consistent" with the bodily makeup of one of 46 lacrosse players who gave DNA samples for testing.

The paper cites several sources and said scientists also ruled out a possible match with any of the other 45 students, according to the sources.

If accurate, the fingernail tissue match would offer the first DNA evidence potentially linking the dancer and an alleged attacker.

But because a complete DNA pattern was not obtained from the tissue, it was not possible to match it with the nearly 100 percent certainty that DNA results usually offer, the sources added.

Now, NBC-17 has learned that the player is not one of the two already accused in the case -- Reade Seligmann, of Essex Fells, N.J., and Collin Finnerty, of Garden City, N.Y. He is, however, a player that the alleged rape victim picked out in a police lineup with 90 percent certainty.

The 27-year-old North Carolina Central University student told police she was beaten and raped by three lacrosse players while she performed at a March 13 team party. She said she clawed at the players in an effort to fight them off.

Defense attorneys claim, however, that nothing about the reported possible DNA match means anything to the case if you look at the type of fingernails, where they were found, and if you look at a picture of the accuser's hand shortly after she arrived at the party.

According to defense attorneys, police found four stick-on acrylic fingernails in a trashcan at 610 Buchanan Street, the house where the party took place. The tissue connected to the possible DNA match was found under one of those fingernails.

But defense attorneys said the third player accused lived at the house and it is no surprise that trace amounts of his DNA could be found inside his own trashcan. They also said they don't believe the type of fingernails that were found -- the kind that are applied with an adhesive strip -- actually ripped off during an attack. They don't believe the fingernails were ever applied and they say they have pictures to prove it.

NBC-17 has seen a picture of the dancer's hand at the house when she performed her dance routine. It appears that long, fake fingernails were on some of her fingers in that photo, but not all of them.

Other photos show what defense lawyers believe is red fingernail polish on the walls of the house and on the railing outside the house. They believe the accuser was painting and applying her nails while at the party.

Defense attorneys admit that none of them have seen the DNA report the Herald Sun article is based upon, but they said if District Attorney Mike Nifong has the DNA report, their clients are entitled to see it.

"I wasn't surprised to hear that. I feel like we should have learned it before," he said.

Kim Roberts, another dancer who performed at the party where the alleged attack took place, paid an emotional visit to the accuser's parents on Thursday.

"It was real emotional -- she was crying, my wife was crying. She said that she was sorry she left (outside) the house before my daughter did," the accuser's father said.

"..."this type" of testing..."

must be amplification then PCR

PCR is an abbreviation for "polymerase chain reaction." (POLL'-IM-ER-ACE). This term applies to a wide variety of different DNA tests that differ in reliability and effectiveness. Reliabilities of each kind of PCR test need independent verification. PCR itself doesn't accomplish DNA typing, it only increases the amount of DNA available for typing.

PCR uses constant regions of DNA sequence to prime the copying of variable regions of DNA sequence.

PCR typically uses two short pieces of known DNA called primers (small arrows below). These serve as starting points for the copying of a region of DNA.

It is worth considering contamination early in this discussion since this is a well-recognized limitation. Unfortunately, the importance contamination in PCR is often underestimated. PCR copies DNA efficiently if the initial DNA is in good condition. A single DNA entity (molecule) can become millions or billions of DNA molecules in about three hours. The PCR process is sometimes compared to a Xerox machine since many copies are made. While initially, this is a useful comparison, it doesn't communicate the true, chain-reaction nature of PCR. In PCR, the original DNA is copied, then the copies are copied, those copies are copied and so on. This results in dramatic increases in the amount of DNA that couldn't be easily accomplished in the Xeroxing analogy. The PCR process deserves its classification as a "chain-reaction" because it has much in common with other chain reactions such as avalanches.

PCR is also very similar to what happens when a clinical infection occurs. Clinicians have known for many years that a single germ (bacterial cell or virus) contaminating a wound can produce a massive infection. Similarly, a DNA molecule can contaminate (infect) a PCR and become a significant problem. The ability of small amounts of DNA to produce false and misleading results is well-known and well-documented within the research community, where the technology originated. Anyone who has caught a cold from an unknown source, or who has a pollen allergy should have some sense of how easily PCRs are contaminated. Actually, it is probably easier to contaminate a PCR than to catch a cold since unlike our bodies, PCRs lack immune systems. The only protection PCRs have is the technique of the analyst, use of control samples to monitor contaminants and careful interpretation.

Prevention of false results involves the use of carefully applied controls and techniques. As described later, such controls and techniques can rarely guarantee that contamination hasn't influenced the results. In forensic DNA testing, some of the scientifically worst-case scenarios can be prevented by keeping DNA samples from known individuals well out of range of other items of evidence at all stages. Most forensic DNA laboratories perform negative controls, blank samples that will often detect contaminants in the laboratory. The blanks detect contaminants by showing partial or full DNA profiles representing the contaminants. Alternatively, the blank may show no profile, consistent with, but not proving that contamination didn't occur. Unfortunately, a few forensic DNA laboratories omit their controls. A few favor the controls by using special equipment on them, or by not carrying them through the entire procedure. Such practices are hazardous, especially when an important evidentiary sample has a low amount of DNA, degraded DNA, or otherwise presents as a minimal or partial (see below) sample. In short, while PCR is a useful research tool, all applications require extreme care and vigilance.
snipped from:

http://www.scientific.org/tutorials/articles/riley/riley.html

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