AFTE Store - Proposed “Congruent Matching Cells (CMC)” Method for Ballistic Identification and Error Rate Estimation

The 3D measurement and correlation on “correlation cells” were proposed at the National Institute of Standards and Technology
(NIST) for establishing the NIST Ballistics Identification System (NBIS) [1]. Based on the concept of correlation
cells, a Congruent Matching Cells (CMC) method is proposed for accurate ballistic identification and error rate estimation
using three sets characteristic parameters of the paired correlation cells: cross correlation function maximum CCFmax,
spatial registration positions in x-y and registration phase angle θ. The proposed CMC method can be used for correlation
of both geometrical topographies and optical images. The “congruent matching” method can be potentially applied for all
case scenarios of fired cartridge cases, fired bullets, and toolmarks. The CMC parameters and algorithms are in the public
domain and subject to open tests. High-speed correlations are ensured by “synchronous processing” of multiple correlation
cell pairs at the same time. Based on the CMC method, an error rate procedure is proposed for establishing a statistical
foundation to support nationwide ballistics identifications in forensic science, and to provide an error rate report for court
proceedings in a manner similar to the method used for reporting the Coincidental (Random) Match Probability (CMP) in
forensic identification of DNA evidences.

Full Journal: AFTE Journal Vol 47 No 3 (2015)