title: Fitting the Balding-Nichols model to forensic databases.
abstract: Large forensic databases provide an opportunity to compare observed empirical rates of genotype matching with those expected under forensic genetic models. A number of researchers have taken advantage of this opportunity to validate some forensic genetic approaches, particularly to ensure that estimated rates of genotype matching between unrelated individuals are indeed slight overestimates of those observed. However, these studies have also revealed systematic error trends in genotype probability estimates. In this analysis, we investigate these error trends and show how they result from inappropriate implementation of the Balding-Nichols model in the context of database-wide matching. Specifically, we show that in addition to accounting for increased allelic matching between individuals with recent shared ancestry, studies must account for relatively decreased allelic matching between individuals with more ancient shared ancestry.
authors.affiliation: University of California, Berkeley, Department of Integrative Biology, United States. Electronic address: rrohlfs@berkeley.edu.
authors.forename: Rori V
authors.initials: RV
authors.lastname: Rohlfs
authors.affiliation: Universidade Federal do Espírito Santo, Departamento de Ciências Biológicas, Brazil.
authors.forename: Vitor R C
authors.initials: VRC
authors.lastname: Aguiar
authors.affiliation: University of California, Los Angeles, Department of Ecology and Evolutionary Biology, United States.
authors.forename: Kirk E
authors.initials: KE
authors.lastname: Lohmueller
authors.affiliation: Laboratório Hermes Pardini, Departamento de Genética Molecular, Brazil.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Castro
authors.affiliation: Laboratório Hermes Pardini, Departamento de Genética Molecular, Brazil.
authors.forename: Alessandro C S
authors.initials: ACS
authors.lastname: Ferreira
authors.affiliation: Laboratório Hermes Pardini, Departamento de Genética Molecular, Brazil.
authors.forename: Vanessa C O
authors.initials: VCO
authors.lastname: Almeida
authors.affiliation: Universidade Federal do Espírito Santo, Departamento de Ciências Biológicas, Brazil.
authors.forename: Iuri D
authors.initials: ID
authors.lastname: Louro
authors.affiliation: University of California, Berkeley, Department of Integrative Biology, United States.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Nielsen
mesh_terms: D000483:Alleles; D030541:Databases, Genetic; D053803:Forensic Genetics; D006801:Humans; D016013:Likelihood Functions; D008957:Models, Genetic
keywords: Balding–Nichols model; DNA database; Partial match probability; Population genetics