ANSI/NIST-ITL Standard 

Workshop 2013 

Firearm Evidence Surface 

Database; an Initiative 

Proposal 

Robert M. Thompson 

Program Manager – Forensic Data Systems 
Firearm Evidence 
Source of Tool Marks 
Source of Tool Marks 
Breechface & Firing Pin Impressions 
Rifling in Barrel 
Barrel Rifling Engraving on Bullet 
Cartridge Case Comparison 
Bullet Comparison, One “Land” Engraved 

Area 
Laboratory Examination & Ballistic Search 

Systems 
Objective Criteria for Identification 
NIST 3D Measurement System 

12

Specifications: 

• Measurement field: 

800/320 μm 

• for 20x and 50x lens. 

• X/Y-Resolution: 

1.5/0.6 μm. 

• Z-Resolution: 20/10 

nm. 

Nanofocus Nipkow disk 

confocal microscope 
Example of High Reproducibility of 

Topography Measurements 

13

(1)

(2)

(3)

(4)

(5)

 Measurement comparison of four techniques tracing the same SRM bullet: 

 (1) Virtual standard traced on a ATF master bullet used as a reference; 

 (2) Stylus instrument traces a SRM bullet: CCFmax = 99.6%; 

 (3) Interferometric microscope: CCFmax = 92.1%; 

 (4) Nipkow disk confocal microscope: CCFmax = 99.0%; 

 (5) Laser scanning confocal microscope: CCFmax = 95.3%. 
Evaluation of the Similarity 

14
Application of CCF in NIST Standard 

Bullet Comparisons 

15

Land 1-3 

Land 4-6 

An example of CCF calculation result 
For Actual Bullets 

16

Bullet signature 

Data acquisition 

Processing 

correlation 
Selection of Valid Correlation Areas 

17

Land impression images may include areas that contain useless or 

wrong striation information (in red). 

Question: 

Can valid striated areas be intelligently distinguished from other 

invalid areas? 
CCF Results 

18

LEA comparison Bullet comparison 

Correlation values of all ten pairs of known-matching bullets scored 

highest on their correlation lists, yielding a correct identification 

rate 100 %. 

For 15 unknown bullets, all 30 pairs of matching bullets scored at 

the topmost position on their respective correlation lists. (Blind 

Test) 

See case 

analysis 
Case Analysis 

19

Confocal raw images; LEA to LEA comparison 

Processing 

There is only one comparison of matching LEA that did 

not have highest correlation score (22.85 %) 
Optical and Topography Data Files 
Early Attempt for Standard Interchange 

1996

The National Institute of Standards (NIST) in Gaithersburg, 

Maryland, was directed to provide technical assistance to 

assist with "ballistic imaging interoperability" between the 

DRUGFIRE and IBIS technologies. 

1997

The ATF and the FBI agreed to make DRUGFIRE and 

IBIS® systems compatible. As a result, the National 

Integrated Ballistic Information Network Program (NIBIN) 

was established. 

(NIJ/AFTE Training Module 2) 
No Interoperability? FAIL! 

• As bullets fly, info doesn’t 

FBI, ATF ammo-tracing systems can’t interact After three 

years of research, officials from the National Institute of 

Standards and Technology (NIST) believe that by the end of the 

year they will have nailed the problem of reconciling two 

competing and incompatible bullet-tracing systems, one 

developed by the FBI and the other by the Bureau of Alcohol, 

Tobacco and Firearms. Still, no one is making any promises. 

 NIST was brought in as a neutral third party in 1996 by 

lawmakers and others who realized that millions of dollars were 

being spent on two programs that worked along parallel lines —

the FBI’s Drugfire system, and ATF’s Integrated Ballistics 

Identification System (IBIS). The NIST was asked to develop a 

standard for interoperability so that they could share information. 

What was quickly determined was that there was no way to write 

such a standard... Law Enforcement News, October 15, 1999
Pictures Courtesy of Leica Microsystems 

Comparison Microscope 

23
Comparison Microscope Images 

24
Nipkow Disk Confocal Microscope 

25
Measurement Setup 

26
Breech Face Firing Pin Ejector 

Mark 

Confocal Microscope Data 

27
Data Trimming 

28
Data Trimming 

29
Gaussian Filter 

Removes 

Form and 

Waviness 

Long 

Wavelength 

Cutoff 

λc = 0.3 mm 

Data Filtering 

30
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ACCV is a Standard Statistical Function 

Areal Cross Correlation Equations 

31
Non-matches: 

Mean= 0.3056 

Standard Deviation= 0.0457 

Matches: 

Mean = 0.8216 

Standard Deviation = 0.0534 

Distribution Cutoff CCF: 

0.5444 

Our Cutoff CCF: 

μ - 3σ = 0.6614

Probability Density Function 

Statistical Analysis 

32
33

Unknown R Known 7A 

Unknown R Known 7B 
34
35
Measurement Science and Standards in 

Forensic Firearms Analysis 2012 

• The National Institute of Standards and 

Technology (NIST) in collaboration with The 

Association of Firearm and Tool Mark 

Examiners (AFTE) and the Scientific Working 

Group for Firearms and Toolmarks 

(SWGGUN) hosted a two-day conference 

exploring measurement science and 

standards in the forensic discipline of 

firearms analysis. 

• http://www.nist.gov/oles/forensics_firearms_

2012.cfm
Measurement Science and Standards in 

Forensic Firearms Analysis 2012 

In the final discussions concerning the 

“road forward” for the advancement of 

firearm evidence comparisons using 

objective, scientific methods based on 3D 

topography; the development of a usable, 

validated, standardized research database 

where government, academic, and 

commercial researchers could leverage 

was considered a major priority. 
Firearm Evidence Surface Database; A HighLevel Vision of Standard File Transfer and 

Operability 

Open “Sandbox” where there is a somewhat open exchange 

and deposition of database items from academic and 

commercial researchers. Most “rules” determined by the 

players with little outside monitoring. 

 (Photo: Teachlesslearnmore.com) 
Research Database 

• Research Database where a carefully constructed “read 

only” database of optical and topographic files are housed. 

Data entries are qualified as to source, minimum quality, 

and usability. The data would be qualified using peer 

determined factors, and standard file formats and transfer 

methods determined. Registered/qualified users would 

have moderated access. 
Sequestered Database 

Sequestered database for performance testing. Similar to 

the research database in regards to controls and standards, 

but not available for the users. The database would be 

used for independent performance tests where reports are 

provided after testing. 

 Photo: motifake.com 
Firearm Evidence Surface Database 

Challenges 

• Image size(s) 

• x, y, and z resolution in SI units? 

• Format(s) for data, images, file types? 

• Other compatible image and metadata formats? 

• Hardware and software space, where installed? 

• Size of statistically valid databases for research and 

performance testing? 

• Costs for the construction, maintenance, and management 

of the initiative? 

• Peer input in the development, database use, and quality 

management? 

• Expansion to other forensic databases; footwear, tires 

tracks, etc. 
Firearm Identification in the Forensic 

Science Laboratory by 

Robert M. Thompson 

http://ndaa.org/pdf/Firearms_identity_NDAAsm.pdf 
QUESTIONS? 

Robert M. Thompson 

Email: robert.m.thompson@nist.gov

Telephone: 703-924-0821