'This could easily be a composite profile'
At the crux of the evidence is the DNA profile referred to as Unknown Male 1.
That profile was first developed in late 1998 and early 1999 from tests on JonBenet's panties — but analysts couldn't at that time identify sufficient genetic markers. Sending it to the FBI's Combined DNA Index System — the national genetic database commonly known as CODIS — requires at least 10 markers.
Further lab work in 2003 yielded an additional marker, and the profile, featuring the required minimum of 10 genetic markers, was entered into CODIS that December.
"People believed back in those days almost all mixtures are two-person mixtures — that was like gospel truth," said Phillip Danielson, a professor of molecular biology at the University of Denver and science adviser to the National Law Enforcement and Corrections Technology Center.
In the ensuing years, as the "kits" used to detect DNA became ever more sensitive, scientists came to realize that many mixtures contained genetic markers from more than two people.
"You know," Danielson said, "looking at the profiles in this case, it seems pretty clear that their idea of this 'unknown male' — this could easily be a composite profile. Meaning that we have multiple contributors. But because of the low sensitivity of the kit, they interpreted those multiple contributors as being just one extra person."
http://www.9news.com/news/investiga...-the-dna-in-the-jonbent-ramsey-case/343376600