Uncertainty in the number of contributors in the proposed new CODIS set.
The probability that multiple contributors are detected within a forensic DNA profile improves as more highly polymorphic loci are analysed. The assignment of the correct number of contributors to a profile is important when interpreting the DNA profiles. In this work we investigate the probability of a mixed DNA profile appearing as having originated from a fewer number of contributors for the African American, Asian, Caucasian and Hispanic US populations. We investigate a range of locus configurations from the proposed new CODIS set. These theoretical calculations are based on allele frequencies only and ignore peak heights. We show that the probability of a higher order mixture (five or six contributors) appearing as having originated from one less individual is high. This probability decreases as the number of loci tested increases.
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA. Electronic address: mcoble@nist.gov.
Michael D
MD
Coble
ESR, Private Bag 92021, Auckland 1142, New Zealand; University of Auckland Department of Statistics, Private Bag 92019, Auckland 1142, New Zealand.
Jo-Anne
JA
Bright
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA; ESR, Private Bag 92021, Auckland 1142, New Zealand.
John S
JS
Buckleton
University of Auckland Department of Statistics, Private Bag 92019, Auckland 1142, New Zealand.
James M
JM
Curran
D004247:DNA / Q000235:genetics*; D053803:Forensic Genetics; D006801:Humans; D044382:Population Groups / Q000235:genetics; D011336:Probability; D035501:Uncertainty
D004247:DNA
Forensic DNA; Interpretation; Mixed DNA profiles