Related Experiment Video
Updated: Jan 5, 2026
10:14
Chromatographic Fingerprinting by Template Matching for Data Collected by Comprehensive Two-Dimensional Gas Chromatography
Published on: September 2, 2020
5.4K
Fired bullet signature correlation using the Congruent Matching Profile Segments (CMPS) method
Zhe Chen1, Wei Chu2, Johannes A Soons2
1School of Mechatronics Engineering, Harbin Institute of Technology (HIT), Harbin, 150001, China; Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA.
Forensic Science International
|October 21, 2019
Summary
A new Congruent Matching Profile Segments (CMPS) method objectively compares striated tool marks, improving accuracy for bullet signature analysis. This novel approach enhances forensic ballistics by segmenting profiles for more reliable comparisons.
Area of Science:
- Forensic Science
- Ballistics
- Pattern Evidence Analysis
Background:
- Objective comparison of striated tool marks is crucial in forensic ballistics.
- Existing methods face challenges with varying scales and poor similarity in striae profiles.
- The congruent matching cell (CMC) method was previously developed for impressed tool marks.
Purpose of the Study:
- Introduce the Congruent Matching Profile Segments (CMPS) method for objective comparison of striated tool marks.
- Enhance the accuracy of bullet signature correlations.
- Address limitations of whole-profile correlation methods.
Main Methods:
- The CMPS method segments one profile and correlates each segment with the other profile.
- Utilizes normalized cross-correlation with multiple peak inspection.
- Applied to land engraved areas (LEAs) of bullets fired from consecutively manufactured barrels.
Main Results:
- Demonstrated clear separation between CMPS scores for known non-matching (KNM) and known matching (KM) LEA profiles.
- Achieved improved comparison accuracy compared to whole-profile correlation coefficient scores.
- Tested on 35 bullets from 10 pistol barrels, analyzing 549 KNM and 46 KM profiles.
Conclusions:
- The CMPS method provides an objective and accurate approach for striated tool mark comparison.
- Offers potential for statistical error rate estimations due to numerous segment correlations.
- Represents a significant advancement in forensic tool mark analysis and bullet identification.
Related Concept Videos
01:17Sign Test for Matched Pairs
364
The sign test for matched pairs offers a robust method for comparing two paired samples, often for the effects of an intervention in one of them. This method is very useful in situations where the underlying distribution of the data is unknown. The test compares two related samples—often pre- and post-treatment measurements on the same subjects—to determine if there are significant differences in their median values.
To conduct the sign test, we first calculate the differences in...
To conduct the sign test, we first calculate the differences in...
364
01:03IR Frequency Region: Fingerprint Region
1.8K
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...
1.8K
01:09Wilcoxon Signed-Ranks Test for Matched Pairs
431
The Wilcoxon signed-rank test for matched pairs evaluates the null hypothesis by combining the ranks of differences with their signs. It essentially tests whether the median of the differences in a population of matched pairs is zero. Since the test incorporates more information than the sign test, it generally yields more trustable conclusions. This test also does not require the data to follow a normal distribution, but two conditions must be met for it to be applicable: (1) the data must...
431
01:10Calibration Curves: Correlation Coefficient
4.4K
In a linear calibration curve, there is a value called the calibration coefficient, denoted by 'r,' which measures the strength and the direction of association between two variables. The correlation coefficient value ranges from −1 to +1. A value of +1 indicates a perfect positive linear correlation, −1 denotes a perfect negative correlation, and 0 implies no correlation between the two variables. A positive correlation value establishes that as one variable increases, the...
4.4K
01:182D NMR: Overview of Heteronuclear Correlation Techniques
710
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
710