The evidential value of STRs - An analysis of exclusion cases

In this study, a total of 191 cases with STR exclusions out of 591 paternit y cases were analysed using 2 STR sets, i.e. (set a) 5 STRs in 462 cases wi th 150 exclusions and (set b) 9 STRs in 129 cases with 41 exclusions. Set ( a) was associated with four exclusions on average while set (b) showed five exclusionary loci on average. Double exclusions were observed in Is cases and further elaborated. Of these, 2 ended up with probabilities of paternit y of 0.1% and 0.4%, respectively and with a random occurrence of the hypoth esis "mutation" of 1:20,000 and 1:50,000, respectively, while all other cas es were associated with much lower frequencies. The conclusion is that the evidential value of a set of highly polymorphic STRs applied in paternity c ases is usually extremely high.