NCJ Number
227242
Journal
Forensic Science International: Genetics Volume: 3 Issue: 3 Dated: June 2009 Pages: 200-201
Date Published
June 2009
Length
2 pages
Annotation
Since guidance exists on how to count DNA matches between samples in a crime sample database but a definition of how to estimate a match rate cannot be found, this paper proposes a method that does not proceed from the match-counting definition but which has a strong logic.
Abstract
There are now several authoritative documents that define what should constitute a match between stains from different crime scenes and how the number of matches should be counted. Both the Senior Managers of Australian and New Zealand Forensic Laboratories (SMANZFL) and the European Network of Forensic Science Institutes (ENFSI) DNA Working Group suggest that matches should be counted in the same way. Specifically, a pair of corresponding profiles should be counted as one match, a set of three as two matches, and set of four as three matches, and a set of N as N-1 matches; however, neither document is explicit regarding the manner in which the crime-to-crime match rate should be estimated. This paper proposes such a method. This method does not evolve from the suggested method for counting matches; however, the authors believe it is the logical method. The authors are unable either to find it published anywhere or to find any international authority for this method; however, the proposed recommendation has been endorsed by the New Zealand and Australian Biological Specialist Advisory Group. 6 references