Performance Study of a Score-based Likelihood Ratio System for Forensic Fingermark Comparison.
In this article, the performance of a score-based likelihood ratio (LR) system for comparisons of fingerprints with fingermarks is studied. The system is based on an automated fingerprint identification system (AFIS) comparison algorithm and focuses on fingerprint comparisons where the fingermarks contain 6-11 minutiae. The hypotheses under consideration are evaluated at the level of the person, not the finger. The LRs are presented with bootstrap intervals indicating the sampling uncertainty involved. Several aspects of the performance are measured: leave-one-out cross-validation is applied, and rates of misleading evidence are studied in two ways. A simulation study is performed to study the coverage of the bootstrap intervals. The results indicate that the evidential strength for same source comparisons that do not meet the Dutch twelve-point standard may be substantial. The methods used can be generalized to measure the performance of score-based LR systems in other fields of forensic science.
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB, The Hague, Netherlands.
Anna Jeannette
AJ
Leegwater
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB, The Hague, Netherlands.|University of Twente, Drienerlolaan 5, 7522 NB, Enschede, Netherlands.
Didier
D
Meuwly
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB, The Hague, Netherlands.|University of Amsterdam, KdVI, PO Box 94248, 1090 GE, Amsterdam, Netherlands.
Marjan
M
Sjerps
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB, The Hague, Netherlands.
Peter
P
Vergeer
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497GB, The Hague, Netherlands.
Ivo
I
Alberink
Bayesian framework; automated fingerprint identification system; fingermarks; fingerprints; forensic science; likelihood ratio; strength of evidence