Just to show how complicated the DNA matching is in some cases, a mail from Michael Nance about it.
The relationship between NamUs and CODIS is confusing at best.
The FBI maintains the Combined DNA Index System (CODIS). Any CODISlab can submit DNA into CODIS. State law enforcement crime labs are CODIScertified and can enter DNA into CODIS. The University of North TexasCenter for Human Identification (UNTCHI) is the Texas State Crime Lab. UNTCHI also does DNA for missing and unidentified persons for any lawenforcement agency in the United States. Not everyone uses UNTCHIhowever. For example California, by state law, sends theirmissing/unidentified DNA to their California state crime lab. There areother agencies who use their own labs as well. Ultimately all DNA arrivesat national CODIS in Washington D.C.
UNTCHI and NamUs are both managed by the University of North TexasHealth Science Center. While NamUs advocates for and assists agencies tocollect DNA and to get it into CODIS, CODIS does not communicate back toNamUs. CODIS only reports back to the law enforcement agency submittingDNA of any association. If there is no association there is no reportback.
NamUs staff members at the University of North Texas Health Sciencecenter work to update NamUs with DNA profiles completed at UNTCHI. Oftenthis is not up to date or comprehensive. When there is an association andan identification made then those NamUs records are archived. It isalmost impossible to go into NamUs and manually complete DNA exclusions forevery permutation possible in NamUs’ MP and UP databases. Also withoutcomplete DNA information it would be foolhardy to make exclusions.
I hope that this helps to explain why so many NamUs records don’t havethese exclusions listed.