Here's an article in the Daily Camera which covers the contamination:
http://www.dailycamera.com/bdc/county_news/article/0,1713,BDC_2423_4937937,00.html
DNA may lead to dead endBy Vanessa Miller, Camera Staff Writer
August 23, 2006
DNA swiped from John Mark Karr after his arrest last week in connection with the JonBenet Ramsey murder might be irrelevant, in part because "something got screwed up" when samples were taken from the crime scene in 1996, a former investigator on the case said. Bill Wise, former first assistant with the Boulder County District Attorney's Office, said that although DNA "absolutely could be one of the biggest things in the case," it could also be nothing.
Some of the DNA taken from the 6-year-old pageant queen's fingernails and underwear was "degraded," Wise said. He said the tool used to take samples wasn't clean.
"It had foreign DNA on it," he said.
The other "minuscule" sample, which is probably blood, was mixed with JonBenet's DNA, he said. That leaves investigators with the daunting task of trying to match a partial DNA strand with a sample from John Karr.
"The amount of DNA is small enough that it could exclude someone. But it could not go so far for the inclusion," Wise said.
Partial strands might narrow possible matches down to one person in every 100,000, he said.
