Large scale database experiments to assess the significance of matching DNA profiles

Over 5,700 three-probe VNTR DNA profiles collected by several United Kingdom (UK) laboratories have been compared to examine the probability of randomly matching 2 samples from different individuals. In over 16 million comparisons, using a matching rule corresponding to the matching guideline employed by the UK Forensic Science Service, no profiles were found to match at the 3 loci D1S7 (MS1), D7S21(MS31) and D12S11 (MS43a). The frequency of occurrence of a set of Caucasian profiles have been estimated with 6 reference databases. The results show that there were greater differences in the frequency estimates when using a database of Afro-Caribbean or Asian profiles, rather than a different Caucasian database. The results further demonstrate the power and robustness of the VNTR DNA profiling technique for forensic casework.