Publications

Displaying 1 - 25 of 292

DEVELOPING DEFINITIONS OF CONVENTIONAL HARDNESS TESTS FOR USE BY NATIONAL METROLOGY INSTITUTES

September 16, 2021

Author(s)

Samuel Low, Jun-Feng Song, Alessandro Germak, Andy Knott, Renato Reis Machado

This paper describes the process used by the Consultative Committee for Mass and Related Quantities - Working Group on Hardness (CCM-WGH) of the International Committee of Weights and Measures (CIPM) to develop international definitions of the conventional

Estimating Likelihood Ratio (LR) for Firearm Evidence Identifications in Forensic Science

September 15, 2020

Author(s)

Jun-Feng Song, Zhe Chen, Theodore V. Vorburger, Johannes A. Soons

Firearm evidence identification has been challenged by the 2008 and 2009 National Research Council (NRC) reports and by legal proceedings on its fundamental assumptions and its procedure involving subjective decisions without a statistical foundation for

Pilot Study on Deformed Bullet Correlation

January 1, 2020

Author(s)

Zhe Chen, Jun-Feng Song, Johannes A. Soons, Robert M. Thompson, Xuezeng Zhao

Most studies on bullet identification address test fire bullet that have near pristine striation marks on the land engraved areas (LEAs). However, in case work, bullets found at a crime scene may be severely deformed or fragmented. The resulting missing

Fired Bullet Signature Correlation Using the Congruent Matching Profile Segments (CMPS) Method

December 1, 2019

Author(s)

Zhe Chen, Wei Chu, Johannes A. Soons, Robert M. Thompson, Jun-Feng Song, Xuezeng Zhao

We introduce the Congruent Matching Profile Segments (CMPS) method for objective comparison of striated tool marks and apply it to fired bullet signature correlations. This method is derived in part from the congruent matching cell (CMC) method developed

Emerging Technology in Comparisons

March 1, 2019

Author(s)

Theodore V. Vorburger, Jun-Feng Song, Nicholas D. Petraco, Ryan Lilien

This chapter is designed to introduce the reader to emerging technologies relating to 3D surface topography measurement and comparative analysis. While the chapter includes several technical terms and a few equations, effort has been made to omit content

A Normalized Congruent Matching Area Method for the Correlation of Breech Face Impression Images

August 6, 2018

Author(s)

Zhe Chen, Jun-Feng Song, Wei Chu, Mingsi Tong, Xuezeng Zhao

The congruent matching cells (CMC) method was invented at the National Institute of Standards and Technology (NIST) for firearm evidence identification and error rate estimation. The CMC method divides the correlated image pairs into cells and uses four

Estimating Error Rates for Firearm Evidence Identifications in Forensic Science

March 1, 2018

Author(s)

Jun-Feng Song, Theodore V. Vorburger, Wei Chu, James H. Yen, Johannes A. Soons, D Ott, Nien F. Zhang

Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed Congruent Matching Cells (CMC) method for image comparisons, its application to firearm identification

Identifying Persistent and Characteristic Features in Firearm Tool Marks on Cartridge Cases

December 13, 2017

Author(s)

Johannes A. Soons, Robert M. Thompson, Jun-Feng Song

To address concerns of subjectivity in firearm evidence examination, algorithms are being developed to compare firearm tool marks imparted on ammunition and generate a quantitative measure of similarity. The goal of this paper is to demonstrate a new

A Convergence Algorithm for Correlation of Breech Face Images Based on the Congruent Matching Cells (CMC) Method

November 6, 2017

Author(s)

Zhe Chen, Jun-Feng Song, Wei Chu, Johannes A. Soons, Xuezeng Zhao

The Congruent Matching Cells (CMC) method was invented at the National Institute of Standards and Technology (NIST) for accurate firearm evidence identification and error rate estimation. The CMC method is based on the principle of discretization. The

Establishing a World-Wide Unified Rockwell Hardness Scale Using Standard Diamond Indenters

February 19, 2017

Author(s)

S Desogus, A Germak, H Ishida, T Polzin, H Yang, Jun-Feng Song, Samuel Low, David J. Pitchure

Recently developed microform measurement techniques have reduced the measurement uncertainties in the geometry of Rockwell diamond indenters. It is now possible to establish standard grade Rockwell diamond indenters characterized by high geometry

Applying 3D measurements and computer matching algorithms to two firearm examination proficiency tests

January 8, 2017

Author(s)

Daniel B. Ott, Robert M. Thompson, Jun-Feng Song

In order for a crime laboratory to assess a firearms examiner's training, skills, experience, and aptitude, it is necessary for the examiner to participate in proficiency testing. As computer algorithms for comparisons of pattern evidence become more

Correlation of Firing Pin Impressions Based on Congruent Matching Cross-sections (CMX) Method

April 20, 2016

Author(s)

Hao H. Zhang, Jun-Feng Song, D Ott, Wei Chu

Comparison of firing pin impressions of cartridge cases is an important part of firearms evidence identification. However, compared with breach face impressions, there is only a limited surface area over which firing pin impressions can be compared

A Review of NIST Projects in Surface and Topography Metrology for Firearm Evidence Identification in Forensic Science

February 10, 2016

Author(s)

Jun-Feng Song, Xianping Liu

This is a review of the National Institute of Standards and Technology's (NIST) efforts in surface metrology and topography measurements for firearm evidence identifications in forensic science. Based on the research projects in surface metrology and

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