Measuring the rarity of core-delta distances in fingerprint patterns in the Dutch population

In latent print examination, a conclusion on an individualization is primarily based on the presence of corresponding minutiae. Depending on the level of correspondence between the minutiae on the fingermark and on the reference print, a match is concluded. However, a fingermark is analyzed on all three levels: general pattern combined with core-delta distance, minutiae, and third-level detail. In the opinion of the authors, next to the conclusion based on minutiae, all information should be included in the final assessment of the evidence if present. In this study, we present the results of frequency data on the combination of fingerprint patterns and their core-delta distances. The frequency data allow examiners to substantiate their subjective opinions on the strength of corresponding patterns and core-delta distances based on measurements. The frequencies of the core-delta distances in this study were obtained by encoding core-delta distances in a collection of more than 20,000 fingerprints containing either a loop or a whorl pattern. The frequencies for the core-delta distances of loop patterns were subsequently compared with data from the National Institute of Standards and Technology. This study will demonstrate that core-delta distances in loop and whorl patterns contribute significantly to the overall evidential strength of fingerprint evidence. By adding pattern and core-delta distance information to the evaluation of fingerprint evidence, more challenging fingermarks could be added to fingerprint case reports.

Automated summary

In latent print examination, a conclusion on individualization is primarily based on corresponding minutiae. Information from general pattern, core-delta distance, and third-level detail should also be included in the final assessment. This study provides frequency data on the combination of fingerprint patterns and core-delta distances, allowing examiners to substantiate their opinions on the strength of corresponding patterns and distances. By adding pattern and distance information to the evaluation of fingerprint evidence, more challenging fingermarks could be included in case reports.