GHEP-ISFG Proficiency Test 2011: Paper challenge on evaluation of mitochondrial DNA results

Abstract

In this GHEP-ISFG exercise, participating labs were invited to evaluate a forensic case in which the mtDNA haplotype from a hair shaft in the victim's hand matched the suspect's haplotype. 31 forensic labs participated in the exercise. Although all except one used the EMPOP database to estimate the haplotype frequencies different final likelihood ratios (LRs) were reported. The main factors affecting these differences were: the origin of the reference population, the approaches to correct sampling errors, the LR formula, the source of EMPOP data (forensic/literature), the type of search (pattern or literal and "disregard Indels" option) and the selected edition range to perform the queries. This demonstrates that further efforts are needed in order to standardize the statistical evaluation of the mtDNA evidence.