Impact of model choice on LR assessment in case of rare haplotype match (frequentist approach)

摘要

The likelihood ratio (LR) measures the relative weight of forensic dataregarding two hypotheses. Several levels of uncertainty arise if frequentistmethods are chosen for its assessment: the assumed population model onlyapproximates the true one and its parameters are estimated through a database.Moreover, it may be wise to discard part of data, especially that onlyindirectly related to the hypotheses. Different reductions define differentLRs. Therefore, it is more sensible to talk about "a" LR instead of "the" LR,and the error involved in the estimation should be quantified. Two frequentistmethods are proposed in the light of these points for the `rare type matchproblem', that is when a match between the perpetrator's and the suspect's DNAprofile, never observed before in the database of reference, is to beevaluated.