_____________________________________________________________________________________

The 47 page SWGGUN response was submitted to the SoFS RDT&E IWG on May 20, 2011. This 94 page 

combined response was submitted on June 14, 2011.

SWGGUN and AFTE Committee for the Advancement of the Science of Firearm 

and Toolmark Identification’s response to 25 foundational firearm and toolmark 

examination questions received from the Subcommittee on Forensic Science 

(SoFS), Research, Development, Testing, & Evaluation Interagency Working 

Group (RDT&E IWG) on April 18, 2011. This response is a compilation of 

published research which addresses each question. 

Foreword to Questions #1 through #9:

Toolmark Identification is an applied science. It is congruous with applied research, 

which uses some part of research communities‘ accumulated theories, knowledge, 

methods and techniques for a specific commercial or client driven purpose. 

Applied science differs from fundamental science. Applied science focuses on practical 

applications with less emphasis on the most basic scientific principles. 

The forensic science discipline of Firearm and Toolmark Identification (FA & TM ID) is 

derived from validated theories in the physical sciences. Specifically, the origination of 

toolmarks is based on previously established theories, principles and properties that 

were adapted in the material and engineering sciences. These essential principles, 

which can be found in innumerable textbooks, are delineated below, followed by a 

limited representative reference list:

I. Physical Properties

A. Pressure

B. Temperature- Friction & Heat

II. Metallurgical Properties

A. Plastic Deformation

B. Stress-Strain Relationships

 C. Failure Mechanics

D. Forces

1. Compression

2. Torsion

3. Shear 

4. Tensile

June 14, 2011 June 14, 2011 1
5. Flexure

III. Mechanical Properties- Materials reaction to applied forces

A. Chip Formation Processes & Phenomena/Theory

B. Non-Chip or Chipless Formation Processes & Phenomena/Theory

1. Electro-chemical machining (ECM)

2. Electro-discharge machining (EDM)

3. Laser 

IV. Surface Integrity 

A. Fatigue/Fracture Mechanics 

B. Hardness

C. Heat Transfer

 D. Texture-

 1. Roughness, Waviness & Lay 

 2. Metrology- Provides standard of three primary components to describe 

 3D Surface texture and supplies a quantitative basis for toolmarks. 

E. Tribology- Established body of knowledge that explains wear and the random 

 affects of tool wear

Fundamental References:

Brandt D., Metallurgy Fundamentals, Goodheart-Wilcox Company Inc., 1985

Ostwald and Munoz, Manufacturing Processes and Systems, John Wiley & Sons, Ninth 

Edition, 1997

Wright R.T., Processes of Manufacturing, The Goodheart-Wilcox Co., Inc., 1987

DuVall J.B., Contemporary Manufacturing Processes, Goodheart-Wilcox Co., Inc., 1996

Hurd D., Silver M., Bacher A.B., & McLaughlin C.W., Physical Science, Prentice-Hall, 

New Edition, 1993 

Salmon, S.C., Modern Grinding Process Technology, McGraw-Hill, Inc., 1992 

June 14, 2011 22
McCarthy WJ and Smith R.E., Machine Tool Technology, McKnight & McKnight 

Publishing, 1968

Ernst and Merchant, Chip Formation, Friction and Finish, The Cincinnati Milling Co., 

Cincinnati, Ohio

De Garmo, E.P., Materials and Processes in Manufacturing, The MacMillian Co., 3rd 

Edition, 1969

De Garmo, E.P., Black, J.T., Kohser, R.A., Materials & Processing in Manufacturing, 

MacMillian Publishing Co., 7th Edition, 1988

Amstead, B.H., Ostwald, P.F., Begeman, M.L., Manufacturing Processes, Wiley & Sons, 

8th Edition, 1987

Wright, T.R., Processes of Manufacturing, Goodheart-Wilcox, 1987

Pollack, H. W., Materials Science & Metallurgy, Reston Publications, 1973

Neely, J., Practical Metallurgy & Materials, Wiley & Sons, 1979

Crossover References

Biasotti, A., ―The Principles of Evidence Evaluation as Applied to Firearms and Tool 

Mark Identification‖, AFTE Journal, Volume 9, Number 4, October 1964.

Burrard, G, The Identification of Firearms and Forensic Ballistics, Butler & Tanner 1934, 

Reprinted Barnes & Company 1962 and Wolfe publishing 1990

Davis, JE, An Introduction to Toolmarks, Firearms and the Striagraph, Charles C. 

Thomas, 1958

Goddard, Waite, Fisher and Gravelle, Army Ordnance, November & December 1925

Gunther J.D., and Gunther C.O., The Identification of Firearms, Wiley & Sons, Inc. 1935

Hatcher, J.S., Textbook of Firearms Investigation, Identification and Evidence, Small 

Arms Technical Publishing Company, 1935

Hatcher Jury & Weller Hatcher, J.S., Jury, F.J. and Weller, J., Firearm Investigation 

Identification and Evidence, The Stackpole Company, 1957.

Mathews, JH, Firearms Identification, Volumes I-III, University of Wisconsin Press, 1962

June 14, 2011 33
Peterson, J.L., "Utilizing the Laser for Comparing Tool Striations"; Journal of the 

Forensic Science Society, 57 (14), 1974, pp. 57-62

Vandiver, J.V., "Identification and Use of Toolmark Identification", Law and Order, No. 7, 

1976

June 14, 2011 44
1. What literature documents the scientific domains used to inform the 

foundations of firearm/toolmark analysis? Have the relevant communities and/or 

standards setting organizations looked to engineering, material sciences, etc. for 

experimental design, lessons learned and research which can inform advancing 

the practice of firearms/toolmark analysis? If so, what references exist to 

document this crossover of information?

See Fundamental and Crossover References mentioned above. 

The history of firearms identification and court acceptance of firearms and toolmark 

evidence in the United States goes back over 100 years and has been the subject of 

numerous publications. The following list of references represents a portion of these 

publications. The last two articles listed represent special contributions made by Kraft in

1931 when he authored a comprehensive two-part summary of the literature produced 

during the period 1919 through 1930 that dealt with (in part one) ―the identification of 

weapons by means of the projectile and cartridge case‖ and (in part two) ―other 

questions that may arise in forensic ballistics." Kraft‘s critical review of many articles 

written in German, etc. made them available to many English speaking examiners for 

the first time. The AFTE Theory of Identification, developed and adopted by the relevant 

scientific community (AFTE in 1992), has provided the toolmark identification 

community with a theory defining and describing the approach that examiners have 

traditionally taken when identifying/individualizing toolmarks. 

Buxton, J., ―The Science of Ballistics: Judicial Applications‖, American Journal of 

Police Sciences, May – June, 1931, 2(3): 211-219

Serhant, J. ―The Admissibility of Ballistics in Evidence‖, American Journal of 

Police Sciences, May – June, 1931, 2(3): 202-210

Baker, N., ―The Campbell Case‖, American Journal of Police Science, Jan – Feb, 

1931, 3(1): 21-31

Inbau, F., ―Scientific Evidence in Criminal Cases (Firearms Identification –

―Ballistics‖)‖, AFTE Journal, Vol. 13, No. 2, 1981: 281 (Originally appeared in 

Journal of Police Science, 1933)

Gunther, J.D., and Gunther C.O, ―The Identification of Firearms‖, Wiley & Sons, 

Inc. 1935.

Goddard, C. ―A History of Firearm Identification‖, AFTE Journal. Vol. 17, No. 1, 

1985, pp. 55 – 68 (Originally printed in Chicago Police Journal, 1936).

FBI, ―Firearms Identification‖, U.S. Government Printing Office, 1941, pp 17 – 33 

―Development and Admissibility of Ballistics and Firearms Evidence‖.

June 14, 2011 55
Goddard, C., ―A History of Firearms Identification to 1930.‖ AFTE Journal, Vol. 

31, No. 3, 1999, pp. 225 – 241.

IAI Firearms Sub-Committee - Stanton O. Berg, Chairman, ―The History of 

Firearms Identification‖, Identification News, June 1965, pp. 5 – 15.

Saferstein, R. ―Firearms Identification – Historical Background‖, Forensic Science 

Handbook – Volume II, Prentice Hall, 1988, see p. 411 – 415.

Hamby, J., ―The History of Firearm and Toolmark Identification‖, AFTE Journal, 

Vol. 31, No. 3, 1999, pp. 266-284.

Kraft, B., ―Critical Review of Forensic Ballistics – Part I‖, American Journal of 

Police Science, Jan-Feb 1931, 2(1), pp. 52 – 66.

Kraft, B., ―Critical Review of Forensic Ballistics – Part II‖, American Journal of 

Police Science, Mar – Apr, 1931, 2(2), pp. 125 – 142.

Moran, B. and Murdock, J. ―Zen and the Art of Motorcycle Maintenance – Contribution 

to Forensic Science – An Explanation of the Scientific Method‖ Appendix No. 2 (pp. 

234-240) from the article by Grzybowski, R., Miller, J., Moran, B., Murdock, J., Nichols, 

R., and R. Thompson titled ―Firearm/Toolmark Identification: Passing the Reliability Test 

Under Federal and State Evidentiary Standards‖ in AFTE Journal, Vol. 35, No. 2, Spring 

2003, pp. 209-241.

This appendix describes how the classical scientific method is used in firearm 

and toolmark identification. Column four in the scientific method chart generally 

describes research of the type summarized by Nichols. It is this research that led 

directly to the adoption of the AFTE Theory of Identification in 1992.

Biasotti, A.A., (1981) Rifling Methods – A Review and Assessment of the Individual 

Characteristics Produced., Association of Firearm and Toolmark Examiners Journal, 

Vol. 13, No. 3, pp. 34-61.

The author reviews the various methods of rifling barrels and the types of marks 

that they produce on bullets.

Biasotti, A., (1981) Bullet Bearing Surface Composition and Rifling (Bore) Conditions as 

Variables in the Reproduction of Individual Characteristics on Fired Bullets Association 

of Firearm and Toolmark Examiners Journal , Vol. 13, No. 2, pp. 94-102.

The purpose of the experiment described herein is to demonstrate the effects of 

several of the more significant variables that may contribute towards the 

reproducibility of identifiable individual characteristics on fired bullets. The author 

discusses individual characteristics via an examination of various types of bullets 

(Lubaloy, Golden, and Nyclad) and various conditions of the bore.

June 14, 2011 66
Nichols, R.G., ―Firearm and Toolmark Identification Criteria: A Review of the Literature‖, 

Journal of Forensic Sciences, Vol. 42, No. 3, 1997, pp.446-474.

A review of 34 articles pertaining to the examination of consecutive manufactured 

tools, identification criteria for firearms and toolmark identification and 

mathematical and computer models developed for a standard identification. 

Nichols, R.G. ―Firearm and Toolmark Identification Criteria: A Review of the Literature, 

Part II‖, Journal of Forensic Sciences, Vol. 48, No. 2, March 2003, pp 318-327.

An update to a previously published review of articles pertaining to firearm and 

toolmark identification criteria is presented. In this update, 22 additional articles 

were reviewed, including works of a general nature, studies critically assessing 

the theory of consecutive matching striations, empirical studies involving various 

firearm components, toolmark studies, as well as articles discussing the utility of 

statistics in the firearms and toolmark identification discipline. These articles have 

been reviewed in a format to permit others to learn what has been published in 

the field in an effort to educate interested parties. Further, a discussion of the 

importance of articulation and communication within the discipline is presented.

Nichols, R.G., Defending the Science of the Firearms and Tool Mark Identification 

Discipline: Responding to Recent Challenges, Journal of Forensic Sciences, Vol. 52, 

No. 3, May 2007, pp. 586-594. 

A compendium of fifty-six (56) references that includes approximately thirty-two 

(32) articles that describe the examination of consecutively, or nearly 

consecutively, manufactured firearms components.

Katterwe, H "Modern Approaches for the Examination of Toolmarks and Other 

Surfaces", Forensic Science Review, Volume. 8, Number. 1, Pp. 46-71, June 1996

The author explores the effects of the production of toolmarks on different 

materials‘ surfaces.

Wiercigroch, M., Cheng A. (1997) Chaotic and Stochastic Dynamics of Orthogonal 

Metal Cutting. Chaos, Solitons and Fractals, 8:4, April 1997, pp. 715-726.

The authors explore the effects of the machining processes as it relates to 

vibration of the machine tools and cutting resistance. It is demonstrated that the 

result is random material grain sizes.

June 14, 2011 77
2. Have studies been conducted at the manufacturing level addressing material 

uniformity, reproducibility, and the QA/QC procedures of the manufacturer? 

Bonfanti, M.S. and DeKinder, ―The Influence of Manufacturing Processes on the 

Identification of Bullets and Cartridge Cases- A Review of the Literature‖, Science and 

Justice, Volume 39, No. 1, 1999, pp. 3-10.

A compendium of fifty (50) references that describe the examination of 

consecutively, or nearly consecutively, manufactured firearms 

components.

Nichols, R.G., ―Firearm and Toolmark Identification Criteria: A Review of the Literature‖, 

Journal of Forensic Sciences, Vol. 42, No. 3, 1997, pp.446-474.

A review of 34 articles pertaining to the examination of consecutive manufactured 

tools, identification criteria for firearms and toolmark identification and 

mathematical and computer models developed for a standard identification. 

Nichols, R.G. ―Firearm and Toolmark Identification Criteria: A Review of the Literature, 

Part II‖, Journal of Forensic Sciences, Vol. 48, No. 2, March 2003, pp 318-327.

An update to a previously published review of articles pertaining to firearm and 

toolmark identification criteria is presented. In this update, 22 additional articles 

were reviewed, including works of a general nature, studies critically assessing 

the theory of consecutive matching striations, empirical studies involving various 

firearm components, toolmark studies, as well as articles discussing the utility of 

statistics in the firearms and toolmark identification discipline. These articles have 

been reviewed in a format to permit others to learn what has been published in 

the field in an effort to educate interested parties. Further, a discussion of the 

importance of articulation and communication within the discipline is presented.

Nichols, R.G., Defending the Science of the Firearms and Tool Mark Identification 

Discipline: Responding to Recent Challenges, Journal of Forensic Sciences, Vol. 52, 

No. 3, May 2007, pp. 586-594. 

A compendium of fifty-six (56) references that includes approximately thirty-two 

(32) articles that describe the examination of consecutively, or nearly 

consecutively, manufactured firearms components.

Springer, E., Toolmark Examinations – A Review of Its Development in the Literature., 

Journal of Forensic Sciences, Vol. 40, No. 6, November 1995, pp.964-8.

A review of forty-seven (47) articles pertaining to toolmark examinations. This 

includes a history of toolmark examinations, a review of its development from 

June 14, 2011 88
1900 to present, and addresses the use of automated technology in conducting 

toolmark examination/ validation .

Coffman, B.C., (2003). Computer Numerical Control (CNC) Production Tooling and 

Repeatable Characteristics on Ten Remington Model 870 Production Run Breech Bolts. 

Association of Firearm and Toolmark Examiners Journal, 35:1, pp. 49-54.

The authors examine ten shotgun bolt faces, consecutively produced by the 

same CNC manufacturing machine tool and compare for the presence subclass 

and individual characteristics. Results of these comparisons found that the 

manufacturing process used to fabricate these bolts produced subclass 

characteristics and sufficient individual characteristics to provide uniqueness.

Lopez, Laura and Sally Grew. ―Consecutively Machined Ruger Bolt Faces.‖ AFTE 

Journal, Vol. 32, No. 1, Spring 2000, pp.19 - 24.

This study warns that one should be careful with microscopic marks from a bolt 

face machined with an end mill. A misidentification is possible unless the 

identification is made using wear or machining ―chatter‖ marks.

June 14, 2011 99
3. What toolmark reproducibility studies have been conducted? 

Bachrach B., Jain A., Jung S., and Koons R.D.(2010) A Statistical Validation of the 

Individuality and Repeatability of Striate Tool Marks: Screwdrivers and Tongue and 

Groove Pliers. Journal of Forensic Sciences, Vol. 55, No. 2, pp 348-357.

Study that statistically validated the original premise of individuality in Toolmark 

Identification by analyzing statistical distributions of similar values resulting 

from the comparison of Known Matches (KM) and Known Non-Matched 

(KNM) pairs of striated toolmarks. This quantifiable analysis of KM and KNM 

toolmark similarity distributions showed nearly error-free identifications.

Doelling, B., ―Comparison of 4000 Consecutively Fired Steel Jacketed Bullets‖, Abstract 

B58, p. 53 from Proceedings of the AAFS Annual Meeting, Seattle, WA, February 19 -

24, 2001

Author examined 4000 fired bullets using conventional pattern matching as well 

as quantitative consecutive matching striation (CMS) techniques

Fadul, T.G., An Empirical Study to Evaluate the Repeatability and Uniqueness of 

Striations/Impressions Imparted on Consecutively Manufactured Glock EBIS Barrels, 

AFTE Journal, Vol. 43,No. 1, Winter, 201, pp.37-44.

An empirical study of ten consecutively manufactured Glock barrels containing 

the Enhanced Bullet Identification System (EBIS). Study consisted of test sets 

sent to 238 examiners from 150 laboratories in 44 states and 9 countries that 

were designed to test the examiner‘s ability to correctly identify fired bullets to the 

barrel that fired them. The results from 183 of these examiners produced an error 

rate of 0.4%. This study validated the repeatability and uniqueness of striated 

markings in gun barrels, as well as the ability of a competent examiner to reliably 

identify fired bullets to the barrels that marked them.

Gouwe, J., Hamby, J.E., Norris, S. (2008). Comparison of 10,000 Consecutively Fired 

Cartridge Cases from a Model 22 Glock .40 S&W Caliber Semiautomatic Pistol. AFTE

Journal, Vol. 40, No. 1, pp. 57-63.

Ten thousand (10,000) .40 S&W caliber cartridge cases fired from a Glock, 

model 22, pistol were compared. All 10,000 fired cases could be identified to 

each other. This study validates previous durability studies that showed 

identifiable markings from a tool could persist for a long period of time.

Hamby, J. Identification of Projectiles. AFTE Journal, Vol. 6, No. 5/6, Fall 1974, pp 22-

24 

Durability study of 501 fired bullets and cartridge cases fired through a worn M16 

rifle. The rifle was fired as quickly as the 20 round magazines could be changed 

June 14, 2011 1010
into the rifle. It was possible to identify fired bullet 1 to bullet 501 as well as 

identifying fired cartridge case 1 to case 501. 

Hamby, J.E., Brundage, D., Thorpe, J., The Identification of Bullets Fired from 10 

Consecutively Rifled 9mm Ruger Pistol Barrels: A Research Project Involving 507 

Participants from 20 Countries. AFTE Journal, Vol. 41, Number 2, Fall 2009, pp. 99 –

110.

Ten consecutively rifled RUGER P-85 pistol barrels were obtained from the 

manufacturer and then test fired to produce known test bullets and 'unknown' 

bullets for comparison by firearms examiners from around the world. This study 

is a continuation of one originally designed and reported on by David Brundage. 

The original study was primarily limited to examiners from nationally accredited 

laboratories in the United States. For this study, the sets were provided to 

firearms examiners around the world. The Ruger P85 pistol and the 10 

consecutively rifled barrels used for the original study were borrowed from the 

Illinois State Police. Ammunition was obtained from the Winchester Ammunition 

Company (A Division of Olin) and 240 tests sets were produced and distributed 

to forensic scientists and researchers worldwide. A thesis which involved a total 

of 201 participants including the original 67 reported on by Brundage was 

published by Hamby and Thorpe in 2001. This paper reports the final conclusions 

of the research conducted by Brundage, Hamby and Thorpe over a 10 year 

period. 

The total number of participants to date (6-2011) is 561 participants from 21 

countries, eight of whom used instrumental analysis to correctly identify the 

consecutively rifled barrels. Also reported within the research was the 

examination and identification of the 16,800 fired cartridge cases produced 

during this experiment. 

Kirby, S. ―Comparison of 900 Consecutively Fired Bullets and Cartridge Cases from a. 

455 Caliber S&W Revolver‖, AFTE Journal, Vol. 33. No. 3, Summer 2001, pp. 113-125.

Durability study of major working edges of a revolver.

Ogihara, Y., et al, ―Comparison of 5000 Consecutively Fired Bullets and Cartridge 

Cases From a 45 Caliber M1911 Pistol‖, AFTE Journal, Vol. 15, No. 3, July 1983, pp. 

127-140. 

Durability study of test-fired bullets and cartridge cases from a single pistol. It 

was possible to identify bullet number 1 to number 5000 and cartridge case 1 to 

number 5000.

Schecter, B., et al. ―Extended Firing of a Galil Assault Rifle‖, AFTE Journal, Vol. 24, No. 

1, January 1992, pp. 37 – 45. 

June 14, 2011 1111
Authors performed extended firings of a new Galil Assault Rifle firing some 7,100 

cartridges. Identifiable ejector marks were successfully compared between case 

number 9 and number 7,060. 

Shem, R. and Striupaitis, P., ―Comparison of 501 Consecutively Fired Bullets and 

Cartridge Cases from a Raven 25 Caliber Raven Pistol‖, AFTE Journal, Vol. 15, No. 3, 

July 1983, pp. 109 – 112. 

Durability study of major working surfaces of a pistol for the test-fired bullets and 

cartridge cases. It was possible to identify bullet number 1 to number 501 and 

cartridge case 1 to number 501.

June 14, 2011 1212
4. As manufacturing techniques and materials change over time, what studies 

have been performed to validate or invalidate older foundational studies? 

Austin, Peter F., ―The Identification of Bullets Fired From High Velocity Rifles with 

Consecutively Rifled Micro-Groove Barrels‖, Presented at the Firth International Meeting 

of Forensic Sciences – University of Toronto, Toronto, Ontario, Canada, June 5 to 11, 

1969.

Author discusses his ability to identify and individualize fired bullets obtained by 

test firing consecutively rifled micro-groove barrels. 

Lutz, M., ―Consecutive Revolver Barrels‖, AFTE Newsletter, No.9, Page 24 (1970).

Author obtained one long revolver barrel, had it cut into two barrels, and then test 

fired both barrels to determine that it was possible to individualize the fired bullets 

to their specific barrel. 

Matty, W.‖ Raven .25 Automatic Pistol Breech Face Tool Marks‖. AFTE Journal, Vol. 16, 

No. 3, Fall 1984, pp. 57-60.

For this study, three consecutively made breechfaces from Raven pistols were 

compared. The concentric toolmarks on the breechfaces were found to be 

individual and not subclass. 

Lyons, D. J. ―The Identification of Consecutively Manufactured Extractors‖, AFTE 

Journal, Vol. 41, No. 3, Fall 2009, pp.246-256.

Study conducted on ten consecutively manufactured firearm extractors. Firearm 

and toolmark examiners from different laboratories were given ten sets of 

cartridge cases marked by these extractors to attempt to make the correct

associations between the known and unknown cases. Each examiner also 

received twelve unknown marked cases in addition to the standards for the ten 

consecutively manufactured cartridge cases, with each known specimen having 

at least one unknown specimen associated with it. 

Hamby, J.E., Brundage, D., Thorpe, J., ―The Identification of Bullets Fired from 10 

Consecutively Rifled 9mm Ruger Pistol Barrels: A Research Project Involving 507 

Participants from 20 Countries‖, AFTE Journal, Vol. 41, Number 2, Fall 2009, pp. 99 –

110.

Ten consecutively rifled RUGER P-85 pistol barrels were obtained from the 

manufacturer and then test fired to produce known test bullets and 'unknown' 

bullets for comparison by firearms examiners from around the world. This study 

is a continuation of one originally designed and reported on by David Brundage. 

The original study was primarily limited to examiners from nationally accredited 

laboratories in the United States. For this study, the sets were provided to 

June 14, 2011 1313
firearms examiners around the world. The Ruger P85 pistol and the 10 

consecutively rifled barrels used for the original study were borrowed from the 

Illinois State Police. Ammunition was obtained from the Winchester Ammunition 

Company (A Division of Olin) and 240 tests sets were produced and distributed 

to forensic scientists and researchers worldwide. A thesis which involved a total 

of 201 participants including the original 67 reported on by Brundage was 

published by Hamby and Thorpe in 2001. This paper reports the final conclusions 

of the research conducted by Brundage, Hamby and Thorpe over a 10 year 

period.

The total number of participants to date (6-2011) is 561 participants from 21 

countries; eight of whom used instrumental analysis to correctly identify the 

consecutively rifled bullets. Also reported within this research was the 

examination and identification of the 16,800 fired cartridge cases produced 

during this experiment. It was possible to individualize fired case number 1 to 

case 16,800.

Fadul, T.G., "An Empirical Study to Evaluate the Repeatability and Uniqueness of 

Striations/Impressions Imparted on Consecutively Manufactured Glock EBIS Barrels", 

AFTE Journal, Vol. 43,No. 1, Winter, 201, pp.37-44.

The author details an empirical study of ten consecutively manufactured Glock 

barrels containing the Enhanced Bullet Identification System (EBIS). Study 

consisted of test sets sent to 238 examiners from 150 laboratories in 44 states 

and 9 countries that were designed to test the examiner‘s ability to correctly 

identify fired bullets to the barrel that fired them. The results from 183 of these 

examiners produced an error rate of 0.4%. This study validated the repeatability 

and uniqueness of striated markings in gun barrels, as well as the ability of a 

competent examiner to reliably identify fired bullets to the barrels that marked 

them.

Fadul, T.G., et al ―An Empirical Study to Evaluate the Repeatability and Uniqueness of 

Striations / Impressions in Fired Cartridge Casings Fired in 10 Consecutively 

Manufactured Slides‖ (This project was supported by Award NO. 2009-DN-BX-K230 

awarded by the National Institute of Justice, Office of Justice Programs, US Department 

of Justice) Presented at the 42nd Annual Training Seminar of the Association of Firearm 

and Toolmark Examiners, held in Chicago, IL on May 29th through June 3rd 2011.

The authors conducted this study to improve understanding of the accuracy, 

reliability, and measurement validity in the firearm and tool mark discipline of 

forensic science. Participants were firearms examiners throughout the United 

States. Some 160 test sets were distributed to laboratories in forty-six states and 

the District of Columbia. 

The test sets were designed to determine an examiner‘s ability to correctly 

identify cartridge casings fired from 10 consecutively manufactured Ruger slides 

June 14, 2011 1414
to test fired cartridge casings fired from the same slides. This empirical study 

established an error rate of less than 0.1 percent. Durability testing established 

that the Ruger slides maintained their individual characteristics after multiple 

firings. 

Hamby, J., and Norris, S., ―The Examination, Evaluation and Identification of 9mm 

Caliber Cartridge Cases From 1275 GLOCK Semiautomatic Pistols Manufactured Over 

an 18 Year Period‖ Presented at the 42nd Annual Training Seminar of the Association of 

Firearm and Toolmark Examiners, held in Chicago, IL on May 29th through June 3rd

2011.

Six hundred and seventeen (617) GLOCK pistols, manufactured in 1993 

were obtained, test fired and the fired cartridge cases examined, evaluated and 

identified to each other. This research was the subject of one chapter of a Ph.D. 

thesis by Hamby at the University of Strathclyde, Glasgow, Scotland.

Over the past 4 1⁄2 years the authors have been examining fired GLOCK cases as 

part of the GLOCK Manufacturing Facilities Quality Assurance Program. Five 

hundred and seventy five (575) cases from the original study were combined with 

700 fired cases from the current study and evaluated and identified against each 

other. These examinations, using conventional optical microscopy, and 

conventional pattern matching techniques resulted in being able to individualize 

the fired cases. Combining the fired cases – manufactured over an 18 year 

period – resulted in a total number of examinations totaling over 1,600,000. 

June 14, 2011 1515
5. Have studies been conducted to review the level of similarity between marks 

produced by consecutively manufactured tools/firearms vs. randomly 

manufactured tools/firearms? 

Stone, R. (2003) How Unique are Impressed Marks, Association of Firearm and 

Toolmark Examiners Journal, 35:4, pp. 376-383.

This study outlines several theoretical types of impressed toolmark 

characteristics (point, line, curve, enclosure and three-dimensional) and applies 

mathematical probability estimates in an attempt to quantify them. It was found 

that with marks of ―reasonable complexity‖ the odds of the same marks being 

repeated on another tool were astronomical.

Collins, E.R., (2005) How ―Unique‖ Are Impressed Toolmarks? – An Empirical Study of 

20 Worn Hammer Faces, Association of Firearm and Toolmark Examiners Journal, 

37:4, pp. 252-295.

This study utilizes 20 worn hammer faces to determine if Stone‘s (2003) 

theoretical types of toolmark characteristics model ―accurately and consistently 

represents the occurrence of individualizing effects.‖ This study includes an 

addendum by Stone which outlines refinements to his original model. The 

refinements to the original model continue to provide probabilities that are 

astronomical.

Hamby, J., and Thorpe, J., ―The Examination, Evaluation and Identification of 9mm 

Caliber Cartridge Cases From 617 Model 17 & 19 Semiautomatic Pistols‖, Association 

of Firearm and Toolmark Examiners Journal, Vol. 41, No. 4, Fall 2005, pp.310-324. 

Six hundred and seventeen (617) GLOCK pistols, manufactured in 1993 

were obtained, test fired and the fired cartridge cases examined, evaluated and 

identified to each other. This research was the subject of one chapter of a Ph.D. 

thesis by Hamby at the University of Strathclyde, Glasgow, Scotland.

Of the 617 pistols that were test fired, 550 had consecutive serial numbers which 

would indicate they were manufactured within a short time frame of each other. 

The others were in different serial number ranges. It was possible to individualize 

the fired cases to themselves and to the exclusion of the other fired cases. 

Howitt D., Tulleners F., ―A Calculation of the Theoretical Significance of Matched 

Bullets‖, Journal of Forensic Sciences, Volume 53, Number 4, July 2008, Pp.868-875.

Study that calculated random occurrence probability for the correspondence of 

impression marks on a subject bullet to a random distribution of similar marks on 

a suspect bullet of the same type. These calculations produced values that 

supported previous reported empirical probabilities on consecutive matching 

June 14, 2011 1616
bullet striae and also indicate that larger consecutive matching sequences are 

extremely unlikely to occur.

Neel M., and Wells M., ―A Comprehensive Statistical Analysis of Striated Tool Mark 

Examinations Part I: Comparing Known Matches and Known Non-Matches‖, AFTE 

Journal, Volume 39, (4), Summer 2007, pp. 176-198.

Study of 4000 striated toolmark comparisons concluded that known matches 

(KM) and known non-matches (KNM‘s) can be statistically distinguished from one 

another with 3D toolmarks containing a 1 in 802,919 and 2D toolmarks 

containing a 1 in 12,090,164 likelihood ratio.

May L., ―Identification of Knives, Tools and Instruments‖ Journal of Police Science Vol. 

1, No. 3, 1930, pp. 247-248.

The author conducted a pioneering study on striated type toolmarks on 

numerous cutting tools, especially knives, with working edges containing some 

type of ground finish. Also, conducted first attempt at a statistical validation in 

Toolmark Identification; in which, it was calculated that the possibility of the same 

identifying mark(s) appearing on another tool is approximately 100,000 X 650 

(quadrillion).

Brackett, J.W. ―A Study of Idealized Striated Marks and their Comparisons using 

Models.‖ Journal of the Forensic Science Society, Vol. 10, No. 1, January, 1970, pp. 27-

56.

Comparison of various proposed probability models for striated marks, with an 

eye toward the development of an automated system. CMS model tended to 

support empirical work of Biasotti.

Deinet, Werner. ―Studies of Models of Striated Marks Generated by Random 

Processes.‖ Journal of Forensic Sciences, Vol. 26 (1), Jan., 1981, pp. 35-50.

Computer-aided studies of the degree of similarity of striated marks are 

described. Digitized image data on 40 grinding marks were fed into a 

minicomputer, and the position values of the lines were determined 

semiautomatically. Idealized models were defined for an objective comparison of 

striated marks and then applied to the grinding mark data. Necessary conditions 

of the models were tested by comparing them with actual, measured properties 

of the marks. Results of the model calculations are presented and the properties 

of the models discussed.

Stone, R., ―How Unique are Impressed Marks,‖ AFTE Journal, Vol. 35(4), Fall 2003, pp. 

376-383.

June 14, 2011 1717
This study outlines several theoretical types of impressed toolmark 

characteristics (point, line, curve, enclosure and three-dimensional) and applies 

mathematical probability estimates in an attempt to quantify them. It was found 

that with marks of ―reasonable complexity‖ the odds of the same marks being 

repeated on another tool were astronomical.

June 14, 2011 1818
6. What studies review the degree of variability that exists in (a) bullet striations 

observable from the same firearm; (b) bullet striations from different firearms

Biasotti, A., (1981) Bullet Bearing Surface Composition and Rifling (Bore) Conditions as 

Variables in the Reproduction of Individual Characteristics on Fired Bullets, AFTE

Journal , Vol.13, No. 2, pp. 94 – 102.

The purpose of the experiment described herein is to demonstrate the effects of 

several of the more significant variables that may contribute towards the 

reproducibility of identifiable individual characteristics on fired bullets. The author 

discusses individual characteristics via an examination of various types of bullets 

(Lubaloy, Golden, and Nyclad) and various conditions of the bore.

Biasotti, A.A., (1959) A Statistical Study of the Individual Characteristics of Fired Bullets, 

Journal of Forensic Science, 4:1, pp. 34-50

Hamby, J. PhD, et al. (2009) ―The Identification of Bullets Fired From 10 Consecutively 

Rifled 9mm Ruger Pistol Barrels: A Research Project Involving 507 Participants from 20 

Countries‖, AFTE Journal 41:2 pp. 99 - 110.

This lengthy undertaking demonstrated that a large number of examiners from 

numerous countries ranging from trainees to highly experienced examiners could 

correctly associate fired 9mm bullets with their parent barrels even though the 

barrels were consecutively rifled with the same broach. If inconclusive answers 

were included, an error rate of 0.059% was found. The comparisons considered 

the normal variability in striae patterns that examiners encounter in bullets fired 

from the same barrel as well as the degree of agreement in individual 

characteristics necessary to affect an identity of source. Numerous additional 

published studies for this same purpose and with the same result, i.e.- bullets 

from consecutively manufactured barrels can be correctly associated with the 

source barrel by trained examiners. These are listed below in order of 

appearance in the peer-reviewed literature. Additionally, many of these studies 

also addressed persistence of matching individual characteristics over repeated 

firings ranging from hundreds to thousands of rounds representing far more shots 

than are likely to occur between the use of a firearm in a crime and its 

subsequent recovery and submission to the crime laboratory. 

Hall, E., (1983) Bullet Markings From Consecutively Rifled Shilen DGA Barrels, AFTE

Journal, 15:1 pp. 33-47

Kirby, S., (1983) Comparison of 900 Consecutively Fired Bullets and Cartridge Cases 

From a .455 Caliber S&W Revolver, AFTE Journal, 15:3, pp. 113-126

Lutz, M., (1970) Consecutive Revolver Barrels, AFTE Newsletter #9, Page 24

June 14, 2011 1919
Matty, W., (1985) A Comparison of Three Individual Barrels Produced From One Button 

Rifled Barrel Blank, AFTE Journal,17:3, pp. 64-69

Miller, J., (2000) An Examination of Two Consecutively Rifled Barrels and A Review of 

the Literature, AFTE Journal, 32:3, pp. 259-270.

Miller, J., (2001) An Examination of the Application of the Conservative Criteria for 

Identification of Striated Tool Marks Using Bullets Fired From Ten Consecutively Rifled 

Barrels, AFTE Journal, 32:2, pp. 125-132.

Murdock, J., (1981) A General Discussion of Gun Barrel Individuality and an Empirical 

Assessment of the Individuality of Consecutively Button Rifled .22 Caliber Rifle Barrels, 

AFTE Journal, 13:3, pp. 84-111

Ogihara, Y., Kubota, M., Sanada, M., Fukuda, K., Uchiyama, T., and Hamby, J., (1983) 

Comparison of 5000 Consecutively Fired Bullets and Cartridge Cases From a .45 

Caliber M1911A1 Pistol, AFTE Journal, 15:3 pp. 127-140

Roberge, D., Beauchamp, A., (2006) The Use of BulletTrax-3D in a Study of 

Consecutively Manufactured Barrels, AFTE Journal 38:2 pp. 166 – 172.

Forensic Technology challenged its newest 3D technology, BulletTRAX-3DTM,

with a test provided by firearms examiner Evan Thompson of the Washington 

State Police Crime Laboratory. This test involves 21 pairs of bullets, among 

which 20 are fired from ten consecutively manufactured 9mm caliber Luger HiPoint barrels. Each of the ten first pairs of bullets is connected to a distinct known 

barrel and is labeled from 1 to 10, the remaining 11 pairs being labeled from A to 

K. The purpose of this test is to correctly match each pair from the first set to a 

pair in the second set. The relation between both sets is given by a confidential 

key, which is a set of ten couples, the first element being a digit (1 to 10), the 

second a letter (in the A-K range). All pairs of bullets in the Thomson test were 

imaged with BulletTRAX-3DTM. From the correlation scores, the key was found 

by a process that can easily be automated by software.

Schecter, B., Silverwater, H., and Etzion, M., (1992) Extended Firing of a Galil Assault 

Rifle, AFTE Journal, 24:1, pp. 37-45

Shem, R. and Striupaitis, P., (1983) Comparison of 501 Consecutively Fired Bullets and 

Cartridge Cases From a .25 Caliber Raven Pistol, AFTE Journal, 15:3, pp. 109-112

Skolrood, R. (1975) Comparison of Bullets Fired From Consecutively Rifled Cooey .22 

Calibre Barrels, Canadian Society of Forensic Science Journal, 8:2, pp. 49-52

Tulleners, F., Giusto, M., Hamiel, J., (1998) Striae Reproducibility of Sectional Cuts of 

One Thompson Contender Barrel, AFTE Journal, 30:1 pp. 62-81.

June 14, 2011 2020
Tulleners, F. and Hamiel, J., (1999) Sub-Class Characteristics of Sequentially Rifled .38 

Special S&W Revolver Barrels, AFTE Journal, 31:2, pp. 117-122

Uchiyama, T., ―Toolmark Reproducibility on Fired Bullets and Expended Cartridge 

Cases‖, AFTE Journal, Vol. 40, No.1, 2008) pp. 3 – 46.

The reproducibility of landmarks, breechface marks and firing pin marks on one 

hundred successively fired bullets and cartridge cases was examined. Three types 

of Speer brand, one of Remington brand and one of DFA brand frangible cartridges 

were fired in a semi-automatic pistol. Remarkable differences were observed in the 

general appearance of the landmarks, breechface marks and firing pin marks which 

were impressed on the different brands of cartridges, even when consecutively fired. 

Identification of the landmarks between bullets from different brands of cartridges 

was difficult because their general appearance differed greatly. Difference in bullet 

diameters was found to be a major cause of changes in landmarks among different 

manufacturer's bullets. Although the depth and number of striations decreased 

gradually, reproducibility of breechface marks on the primers of cartridges was 

rather good. The diameter of firing pin indentations also differed among different 

brands of cartridges. Although the reproducibility of the diameter of circular lines on 

firing pin indentations was good, the detail in these circular lines fluctuated a great 

deal. Quantitative CMS was used as a means of critically evaluating and 

communicating the extent of striated pattern agreement among the rifling 

impressions on the fired bullets in this study.

June 14, 2011 2121
7. Do studies exist which examine the wear rates of materials used to 

manufacture tools/firearms/bullets and cartridge casings and the factors that 

affect wear?

General comments: The various studies related to the rifling of gun barrels, the visible 

changes along the interior surface of a rifled gun barrel (largely, but not exclusively due 

to galling and/or chip formation during the rifling process) are well known to forensic 

firearms examiners. It is these very reasons that bullets from new, consecutively rifled 

barrels can usually be discriminated and associated with the parent barrel. This is 

especially true when the toolmarks from the original drilling process used to form the 

bore of a gun barrel survive the subsequent steps involved in the rifling process. This 

situation is apparent to the forensic firearms examiner upon inspection of the bore of a 

submitted firearm. The random changes that occur over time with use and abuse only 

stand to enhance the differences between consecutively manufactured barrels. This is 

also true for other consecutively manufactured tools. These same reasons and 

phenomena typically apply to the manufacture of the breech faces and breech blocks in 

firearms with these areas being largely responsible for the subsequent markings 

imprinted in the heads and primers of fired cartridge cases. 

The previously cited studies directed exclusively to bullets fired from consecutively 

manufactured gun barrels and listed in response to Question 6 apply here and will not 

be repeated. Some studies that are relevant to tools other than gun barrels are listed 

below. The classic textbooks on firearms identification address the sources of class and 

individual characteristics to varying degrees. These texts are listed separately at the 

end of this response.

Burd, D. and Kirk, P., (1942) Tool Marks: Factors Involved in Their Comparison and Use 

as Evidence, Journal of Police Science, 32:6 pp. 679-686

Burd, D. and Gilmore, A., (1968) Individual and Class Characteristics of Tools, Journal 

of Forensic Science, 13:3 pp. 390-396

Coffman, B., (2003) Computer Numerical Control (CNC) Production Tooling and 

Repeatable Characteristics on Ten Remington Model 870 Production Run Breech Bolts, 

AFTE Journal, 35:1 pp. 49-54

Haag, L., (2007) The Matching of Cast Bullets to the Moulds that Made Them, AFTE 

Journal, 39:4 pp. 313-322 

This article dealt with consecutively machined bullet moulds, subclass (carryover 

marks) and individual characteristics produced by galling and chip formation 

during the machining process. All of these machining marks are reproduced over 

the entire surface of lead and lead alloy bullets cast in bullet moulds. Those 

areas and sites that were the consequence of galling and chip formation were 

obvious upon low power inspection of the surfaces of cast bullets and 

June 14, 2011 2222
represented the individual characteristics that allowed consecutively 

manufactured moulds to be discriminated. 

Hu, J., Chou, K., (2007) Characterizations of cutting tool flank wear-land contact, Wear, 

263 pp. 1454-1458.

Koshy, P., Dewes, R.C., Aspinwall, D.K., (2002) High speed end milling of hardened 

ASI D2 tool steel, Journal of Materials Processing Technology, 127 pp. 266-273.

 This article explores the factors of the machining process that effect tool wear 

and the resulting surface roughness. Various cutting speeds and tool coatings 

were used to evaluate the amount of tool wear and resulting surface roughness. 

The result of this research was wear of a cutting tool regardless of the 

combination of tool speed and tool coating. The tool wear resulted in a varying 

degree of surface roughness (individual characteristics) on all samples.

Lopez, L. and Grew, S., (2000) Consecutively Machined Ruger Bolt Faces, AFTE 

Journal, 32:1 pp. 19-24

Matty, W., (1984) Raven .25 Automatic Pistol Breech Face Tool Marks, AFTE Journal, 

16:3 pp. 57-60

Miller, J., (2001) An Introduction to the Forensic Examination of Tool Marks, AFTE 

Journal, 33:3 pp. 233-248

Rosati C., (2000) Examination of Four Consecutively Manufactured Bunter Tools, AFTE 

Journal, 32:1 pp. 49-50

Classic articles and textbooks dealing with the formation and deposition of class and 

individual characteristics by firearms and various other tools on contacting surfaces 

(listed in order of publication).

Mezger O, Heess W, Hasslacher F, (1931) Die Bestimmung des Pistolensystems aus 

Verfeuerten Hülsen und Geschossen, Archive für Krimologie 89 pp.1-32 und 93-116, 

Verlag von F.O.W. Vogel, Berlin

Mezger, 0., Heess, W., Hasslacher, F., (1931) Determination of the Type of Pistol 

Employed from an Examination of Fired Bullets and Shells," Am. J. Police Science 2:6 

pp. 473-500 (1932) 3:2 pp. 124-146

Burrard, G., (1934) The Identification of Firearms and Forensic Ballistics, Herbert 

Jenkins, Ltd., London, England

Gunther, J., (1935) The Identification of Firearms, John Wiley, New York

June 14, 2011 2323
Hatcher, J., (1935) Textbook of Firearms Investigation, Identification and Evidence, 

Small-Arms Technical Publishing Co., Plantersville, SC

Hatcher, J., Jury, F. and Weller, J., (1957) Firearms Investigation, Identification and 

Evidence, Stackpole Publishing, Harrisburg, PA

O‘Hara and Osterberg, J., (1949) An Introduction to Criminalistics, The Macmillian Co., 

New York

Kirk, P., (1953) Crime Investigation, John Wiley & Sons, New York, London, Sydney, 

Toronto

Davis, J., (1958) An Introduction to Tool Marks, Firearms and the Striagraph, Charles C. 

Thomas Publishing Co., Springfield, IL

Mathews, J., (1962) Firearms Identification-3 Volumes, Charles C. Thomas Publishing 

Co., Springfield, IL

Saferstein, R., (1977) Criminalistics: An Introduction to Forensic Science, Prentice-Hall, 

Inc., Englewood Cliffs, NJ

De Forest, P. Gaensslen, R and Lee, H., (1983) Forensic Science-An Introduction to 

Criminalistics, McGraw-Hill Publishing Co. 

Warlow, T., (1996) Firearms, the Law and Forensic Ballistics, Taylor & Francis, London, 

England & Bristol, PA

June 14, 2011 2424
8. What research exists that examines the durability of firearms/manufacture

tools (screwdrivers, pry bars, hammers, etc.) as a result of wear/tear, care and 

abuse in relation to conservation of markings and their effects on 

identification? 

The numerous, previously-cited persistence studies involving hundreds to thousands of 

rounds fired through a variety of firearms also address this question and will not be republished here. However, the events associated with the discharge of firearms involve 

heat and pressures seldom, if ever, will prevent individual characteristics from being 

deposited on fired cartridge cases and engraved on fired bullets. 

Bacharach, B. (2009) Statistical Validation on the Individuality of Tool Marks Due to the 

Effect of Wear, Environment Exposure and Partial Evidence‖, NIJ/NCJRS Document 

#227929.

An objective, quantifiable toolmark study on marks imparted onto wires by 

diagonal cutters. This study examined the effects of wear, environmental 

conditions and partial toolmark impressions by an automated 3-D system that 

mathematically correlated results of toolmarks to the tools that produced them. 

This study validated, and thus strengthened, the foundations of Toolmark 

Identification. 

Gouwe J., Hamby J.E., Norris, S. (2008). Comparison of 10,000 Consecutively Fired 

Cartridge Cases from a Model 22 Glock .40 S&W Caliber Semiautomatic Pistol, AFTE

Journal, 40:1, pp. 57-63.

Ten thousand (10,000) .40 S&W caliber cartridge cases fired from a Glock, 

model 22, pistol were compared. All 10,000 fired cases could be identified to 

each other. This study validates previous durability studies that showed 

identifiable markings from a tool could persist for a long period of time.

Kirby, S. ―Comparison of 900 Consecutively Fired Bullets and Cartridge Cases 

from a .455 Caliber S&W Revolver‖, AFTE Journal, Vol. 33. No. 3, Summer 

2001, pp. 113-125.

Durability study of major working edges/surfaces of a revolver.

Miller, J. (1998) Cut Nail Manufacturing and Toolmark Identification, AFTE Journal, 30:3 

pp. 492-498

Miller, J. (1998) Reproducibility of Impressed and Striated Tool Marks: 4d Cut Flooring 

Nails, AFTE Journal, 30:4 pp. 631-638

These two articles are especially useful in responding to question 8 in that the 

equipment (tools) used to manufacture cut nails produced both impressed and 

June 14, 2011 2525
striated marks on steel nails that were found to be reproducible and identifiable 

over lengthy production runs involving tens of thousands of cut nails. The ―tools‖ 

consisted of shearing machines, cutters and header punches. Although some 

changes in these toolmarks were observed by the author, nails manufactured 

after 32,000+ specimens could still be matched to initial samples. Toolmarks on 

other sites on these nails changed more rapidly but front and end samples 

ranging from 10,000 to 15,000 units could still be matched on the basis of 

impressed and striated marks produced during the manufacturing processes. 

To quote the author, “Any change in toolmarks left by the cutter or header is so 

gradual as to allow an identification of toolmarks over a long period of 

production.” 

Miller, J. (2001) An Introduction to the Forensic Examination of Tool Marks, AFTE

Journal, 33:3 pp. 233-248

This well-illustrated article with 75 references provides an excellent primer on the 

subject of toolmarks not produced by firearms. It also addresses the sources of 

individuality in a wide variety of tool types and how they can be imparted to 

various receiving surfaces. Finally, and most germane to this question, the author 

specifically comments on the effects of wear and usage and the persistence of a 

tool‘s individuality [page 244 ―Tool Wear‖]

Ogihara, Y., et al, ―Comparison of 5000 Consecutively Fired Bullets and Cartridge 

Cases From a 45 Caliber M1911 Pistol‖, AFTE Journal, Vol. 15, No. 3, July 1983, pp. 

127-140. 

Durability study of major working edges/surfaces of a pistol.

June 14, 2011 2626
9. What literature exists that describes the current state and scope of databases 

related to firearms/bullets/cartridge casings? Have analyses been conducted 

which define the gaps related to databases in firearms and toolmark research? 

Barrett, M., Tajbakhsh, A., Warren, G. (2011) Portable Forensic Ballistics Examination 

Instrument: Advanced Ballistics Analysis System (ALIAS), Association of Firearm and 

Toolmark Examiners Journal 43:1 pp. 74-78.

A portable measurement instrument and analysis tool for use by forensic 

ballistics and firearms examiners that creates, compares and analyses threedimensional, volumetric models of fired cartridge cases and spent bullets. The 

technology can measure and examine toolmarks as small as two microns. ALIAS 

includes computer hardware, an open database infrastructure, a high-precision, 

Swiss-built, application-specific interferometer with a ―six-pac‖ cartridge case or 

expended bullet holder (patents pending) and an open software architecture.

De Kinder, J., Tulleners, F., Thiebaut, H. (2004), Reference Ballistic Imaging Database 

Performance, Forensic Science International, 140, pp. 207-215 

These publications point out the limitations of image storage and search systems 

for fired cartridge cases at the time of these writings. The CALDOJ publication 

lists 9 issues and areas of concern in attempting to apply this technology to large 

databases of newly manufactured semi-automatic handguns. 

The combined American-European study by De Kinder, et al. involved 4200 fired 

cartridge cases from 6 brands of ammunition discharged in 600 model P226 SIGSauer 9mm pistols. The authors realized a 72% success rate when the same 

brand of cartridge case was scanned and entered into the IBIS system with 

success defined as the correct match appearing in the top 10 candidates. This 

fell to 21% when different brands of ammunition were scanned and entered in the

system.

George, W., (2004) The Validation of the Brasscatcher Portion of the NIBIN/IBIS 

System Part Two: Fingerprinting Firearms Reality or Fantasy, Association of Firearm 

and Toolmark Examiners Journal 36:4 pp. 289 – 296.

A study of the Brasscatcher portion of the NIBIN/IBIS system was conducted 

using a database of 850 cartridge cases fired in Smith & Wesson, .40 S&W 

caliber pistols. Correlations were generated for entries from Federal, Winchester 

and Remington brand ammunition and a study to locate the placement of 

matching cartridge cases initiated. Forensic Technology was able to open the 

entire database for viewing instead of the normal user field of 20 %. This study 

provided a real test of the ability of Brasscatcher to identify cartridge cases fired 

from similar firearms, and addresses the concept of fingerprinting firearms for 

use in criminal investigations. During this study an additional advantage 

regarding the second breech face impression image was revealed. The second 

image is not used for correlation purposes.

June 14, 2011 2727
Nennstiel R., Rahm J. (2006) A Parameter Study Regarding the IBIS Correlator; J 

Forensic Sci.,51:1 pp. 18-23

Nennstiel R., Rahm J., (2006) An Experience Report Regarding the Performance of the 

IBIS Correlator, J Forensic Sci., 51:1, pp. 24-30

The articles by Nennstiel and Rahm provide success rate values for the IBIS 

technology for bullet and cartridge cases searches. These authors also found 

that as the database increases the system‘s success rate decreases. 

Tulleners, F., (October 5, 2001) Technical Evaluation: Feasibility of a Ballistics Imaging 

Database for all New Handgun Sales. CALDOJ Publication (a peer reviewed report).

June 14, 2011 2828
10.What studies, if any, have been designed to attempt to falsify the idea that a 

specific tool produced a specific mark to the practical exclusion of all others? 

The numerous studies of consecutively manufactured tools (gun barrels, semiautomatic pistol slides and breech faces, firing pins, knifes, chisels, screwdrivers, etc.) 

all address this very issue. A number of these have been previously listed in response 

to Questions 6, 7 and 8 and will not be republished here. It should not be forgotten or 

overlooked that the final identification determination in any firearm or toolmark 

comparison does not include the entire universe of all firearms or tools in existence as 

the conclusion of Question 10 would suggest. Rather the objective and easily 

measureable Class Characteristics (caliber and cartridge designation, land and groove 

count, land and groove widths, direction of twist for firearms; tip shape and width for 

prying tools, the shape and diameter of the face of a hammer, etc. for tools) that are 

determined first greatly narrow the potential sources of a fired bullet, a fired cartridge 

case, a prymark from a crowbar or an impact mark from a hammer, etc.

FIREARM BIBLIOGRAPHY

Bachrach, Ben. ―Development of a 3D-Based Automated Firearms Evidence 

Comparison System.‖ Journal of Forensic Sciences, vol. 47 (6), November, 2002, pp. 

1253-1264.

This study reports on a computerized system that calculates correlation 

coefficients for comparisons of bullet striation patterns using generated 3-D 

maps of bullet surfaces. Was validated using known matches (KMs) and known 

non-matches (KNMs), so therefore the system arrives at a conclusion of 

identification (or not), with an associated probability of error. Highly relevant to 

our work, because it shows conclusively that an objective observer (a machine) 

detects significant visual differences between KNMs and KMs.

Biasotti, Alfred A. ―A Statistical Study of the Individual Characteristics of Fired Bullets.‖ 

Journal of Forensic Sciences, vol. 4(1), January, 1959, pp. 34-50.

Validity study in which no more than three consecutively matching striations 

(CMS) were found on lead bullets fired from different guns and no more than four 

CMS were found on jacketed bullets fired from different guns.

Brown, C. and W. Bryant. ―Consecutively Rifled Gun Barrels Present in Most Crime 

Labs.‖ AFTE Journal, vol. 27 (3), July, 1995, pp. 254-258.

Study of multi-barreled derringers in which it was assumed that barrels were 

rifled consecutively. One set of derringer test fires showed some good 

June 14, 2011 2929
correspondence in the groove impressions (gross marks), but showed little 

correspondence in the land impressions.

Brundage, David J. ―The Identification of Consecutively Rifled Gun Barrels.‖ AFTE 

Journal, vol. 30(3), Summer, 1998, pp. 438-444.

Validation study in which ten consecutively broach rifled pistol barrels produced 

by Ruger were used to used to test the fundamental claim that qualified 

examiners will rarely, if ever, commit false identifications or false eliminations.

Thirty examiners were given the test nationwide and no misidentifications were 

made.

Bunch, Stephen G. ―Consecutive Matching Striation Criteria: A General Critique.‖ 

Journal of Forensic Sciences, vol. 45 (5), Sept. 2000, pp. 955-962.

This paper critiques the Quantitative Consecutive Matching Striation (CMS) 

approach to toolmark identification. The author discusses the practical and 

theoretical weaknesses of the approach, argues that it demands a 

statistical/probabilistic treatment of results - such as the use of Bayesian 

likelihood ratios - and also suggests much additional research is needed.

DeFrance, Charles S. and Michael VanArsdale. ―Validation Study of Electrochemical 

Rifling.‖ AFTE Journal, vol. 35 (1), Winter, 2003, pp. 35-37.

Validation study in which nine examiners participated in the comparison of bullets 

from electrochemically rifled barrels produced by Smith & Wesson. No 

misidentifications were made.

Fadul, T.G., ―An Empirical Study to Evaluate the Repeatability and Uniqueness of 

Striations/Impressions Imparted on Consecutively Manufactured Glock EBIS Gun 

Barrels‖, AFTE Journal, Volume 43, Number 1, Winter 2011, Pp. 37-44.

An empirical study of ten consecutively manufactured Glock barrels containing 

the Enhanced Bullet Identification System (EBIS). Study consisted of test sets 

sent to 238 examiners from 150 laboratories in 44 states and 9 countries that 

were designed to test the examiner‘s ability to correctly identify fired bullets to the 

barrel that fired them. The results from 183 of these examiners produced an error 

rate of 0.4%. This study validated the repeatability and uniqueness of striated 

markings in gun barrels, as well as the ability of a competent examiner to reliably 

identify fired bullets to the barrels that marked them.

Freeman, Ray A., ―Consecutively Rifled Polygon Barrels,‖ AFTE Journal, vol.10 (2), 

June 978, pp.40-42.

This study documents the comparison of bullets fired through three consecutively 

manufactured polygon barrels produced by H&K for the Model P9S pistol. It was 

June 14, 2011 3030
found that the bullets fired from these barrels could easily be identified to the 

correct barrel. Additionally, these barrels possessed a fluted chamber. Marks 

from the fluted chambers were visible on the bullets and could also be used for 

identification.

Hall, E. ―Bullet Markings from Consecutively Rifled Shilen DGA Barrels.‖ AFTE Journal, 

vol. 15(1), Jan., 1983, pp. 33-53.

Study of consecutively button rifled polygonal style barrels. Conclusion implies 

that there should be no risk of misidentification.

Hamby J. E., Brundage D. J. , Thorpe J. W., ―The Identification of Bullets Fired from 10 

Consecutively Rifled 9mm Ruger Pistol Barrels: A Research Project Involving 507 

Participants from 20 Countries‖, AFTE Journal, Volume 41, Number 2, Spring 2009, pp. 

99-110.

Bullets fired from ten (10) consecutively manufactured barrels were correctly 

identified to the respective barrel that fired them by five hundred-seven (507) 

firearm examiners from twenty (20) countries. This study validates the underlying 

theory that: 1) there are identifiable features imparted by a gun on the surfaces of 

fired bullets that 2) enable a competent firearms examiner to accurately and 

reliably link them to the barrel that fired them. 

Intelligent Automation, Incorporated, ―A Statistical Validation of the Individuality of Guns 

Using High Resolution Topographical Images of Bullets‖, National Institute of Justice 

Grant #2006-DN-BX-K030, October, 2010

Study of marks on fired bullets by a topography based (3D) automated system. 

This study continued the analysis of a previous 2005 NIJ bullet study and 

validated the original premise of Firearm/Toolmark ID. This study also concluded 

that 1) the ability to determine that a given bullet was fired from a specific barrel 

depends on the individual barrel itself and not only on the brand of its 

manufacture, and 2) the performance of the automated analysis system used in 

this study is not representative of that of a trained firearms examiner as humans 

have a remarkable ability to perform pattern matching that is difficult to be 

replicated in any automated system.

Lomoro, Vincent J. ―Class Characteristics of 32 SWL, FIE Titanic Revolvers.‖ AFTE 

Journal, vol. 6 (2), 1974, pp. 18-21.

This paper points out the pitfalls of basing an identification on groove 

impressions on bullets fired from F.I.E. Titanic Revolvers. Bullets from three

different guns were shown to have agreement in the groove impressions, but 

were found to differ significantly in the land impressions.

Lutz, M. ―Consecutive Revolver Barrels.‖ AFTE Newsletter #9, Aug., 1970, pp.24-28.

June 14, 2011 3131
Reported results of the comparison of jacketed and lead bullets fired from two 

consecutively rifled barrels and that the markings on the bullets were identifiable 

and unique to the barrel that fired them.

Matty, William. ―A Comparison of Three Individual Barrels Produced from One ButtonRifled Barrel Blank.‖ AFTE Journal, vol. 17(3), July, 1985, pp. 64-69.

Study of the uniqueness of marks produced on bullets fired from three barrels 

that were produced from the same rifled barrel blank. Subclass characteristics 

noted in the groove impressions, but not in the land impressions. Study also 

notes that over the first few firings the striations on the bullets change 

significantly.

Miller, Jerry. ―An Examination of Two Consecutively Rifled Barrels and a Review of the 

Literature.‖ AFTE Journal, vol. 32 (3), Summer, 2000, pp.259-270.

Study in which bullets were pushed through two consecutively broached.44 

caliber barrels and were examined using Biasotti/Murdock conservative

quantitative CMS (QCMS) criteria for identifications. No misidentifications.

Miller, Jerry. ―Criteria for Identification of Toolmarks, Part II: Single Land Impression 

Comparisons.‖ AFTE Journal, vol. 32 (2), Spring, 2000, pp. 116-131.

This study compares bullets fired by Raven 25 Auto, Lorcin 380 Auto, and 

Stallard Arms 9mm pistols to specimens in the NIBIN database. This study 

supports the Biasotti/Murdock QCMS criteria. 

Miller, Jerry. ―An Examination of the Application of the Conservative Criteria for 

Identification of Striated Toolmarks Using Bullets Fired from Ten Consecutively Rifled 

Barrels.‖ AFTE Journal, vol. 33 (2), Spring, 2001, pp. 125-132.

Using the bullets from the Brundage Ruger ten barrel test, the author: 1) 

identified some very minor subclass characteristics but not sufficient to cause a 

misidentification, and; 2) applied the conservative quantitative CMS criteria which 

resulted in no misidentifications.

Miller, Jerry and Michael McLean. ―Criteria for Identification of Toolmarks.‖ AFTE 

Journal, vol. 30 (1), 1998, pp.15-61.

Using IBIS, the authors compared land impressions of .38 Special jacketed 

bullets fired from S&W revolvers. Found no CMS counts greater than six (6) for 

KNMs, using the computer monitor. Using a separate set of test fires and the 

comparison microscope, no CMS counts greater than four (4) for KNMs were 

found.

June 14, 2011 3232
Murdock, John E. ―A General Discussion of Gun Barrel Individuality and an Empirical 

Assessment of the Individuality of Consecutively Button Rifled .22 Caliber Rifle Barrels.‖ 

AFTE Journal, vol. 13 (3), 1981, pp. 84-95.

This study discusses rifling methods, including the ―new‖ method of button rifling.

Examination of nine barrels (three consecutively rifled barrels from three 

manufacturers) and test fired bullets from each indicated no subclass 

characteristics. First two bullets fired from each barrel could not be identified to 

each other which is indicative of rapid change in a new barrel‘s interior, which in 

turn confirms individuality of barrels.

Skolrood, R. W. ―Comparison of Bullets fired from Consecutively Rifled Cooey .22 

calibre Barrels.‖Canadian Society of Forensic Science, vol. 8(2), 1975, pp. 49-52.

This paper discusses the potential for broaches to produce reproducible gross 

marks and that examiners should be wary of these gross marks.

Smith, Erich. ―Cartridge Case and Bullet Comparison Validation Study withFirearms 

Submitted in Casework.‖ AFTE Journal, vol. 37 (2), Spring 2005, pp. 130-135.

This validation study was designed to test the accuracy of examinations by 

trained firearms examiners who use pattern recognition only (no CMS tabulation) 

as a method for identification. Eight FBI examiners took the test which consisted 

of both bullets and cartridge cases. No false positives or false negatives were 

reported. 

Tulleners, Fred and Mike Giusto. ―Striae Reproducibility on Sectional Cuts of One 

Thompson Contender Barrel.‖ AFTE Journal, vol. 30(1), 1998, pp. 62-81.

For this study, a Thompson Center Contender button rifled barrel was sectioned 

one inch at a time after each test firing. A total of six sections were removed 

from the barrel. Each sections bullets were compared to each other to see how 

much the CMS count had changed. Striae on the bullets were found to be 

significantly altered from one barrel section to the next. The results obtained from 

adjacent barrel sections were apparently comparable to the results Biasotti 

obtained from different, uncut barrels. It was also significant that while total line 

counts differed, the critical observation of CMS generally not exceeding three for 

known non-matching regimes was very consistent between examiners.

Tulleners, Fred and James Hamiel. ―Sub Class Characteristics of Sequentially Rifled .38 

Special S&W Revolver Barrels.‖ AFTE Journal, vol. 31 (2), 1999, pp. 117-222.

This article discusses the potential for sub-class characteristics in S&W revolver 

barrels. The article points out that examiners should be careful when examining 

the groove impressions on fired bullets from broach rifled barrels.

June 14, 2011 3333
Bunch, Stephen G. and Douglas P. Murphy. ―A Comprehensive Validity Study for the 

Forensic Examination of Cartridge Cases.‖ AFTE Journal, vol. 35 (2), Spring 2003, pp. 

201-203.

This validity study used 10 consecutively manufactured Glock slides to 

test the proposition that qualified examiners rarely or never commit 

false positive or false negative errors in cartridge case exams. FBI 

examiners participated in this blind study. False positive and false 

negative rates were 0%.

Coffman, B.C., ― Computer Numerical Control (CNC) Production Tooling and 

Repeatable Characteristics on Ten Remington Model 870 Production Run Breech 

Bolts‖, AFTE Journal, Volume 35, Number 1, Winter 2003, pp. 49-54.

Ten shotgun bolt faces, consecutively produced by the same CNC manufacturing 

machine tool, were examined and compared for the presence of subclass and 

individual characteristics. Results of these comparisons found that the 

manufacturing process used to fabricate these bolts produced both subclass 

characteristics and sufficient individual characteristics to provide uniqueness.

Coody, A.C., ―Consecutively Manufactured Ruger P-89 Slides‖, AFTE Journal, Volume 

35, Number 2, Spring 2003, pp. 157-160.

Ten consecutively produced pistol slide breechfaces were examined and 

compared for the presence of subclass and individual characteristics. Results of 

these comparisons found that the manufacturing processes used to fabricate 

these breechfaces produced both subclass characteristics and sufficient individual 

characteristics to provide uniqueness.

Gouwe J., Hamby J.E., Norris, S., ―Comparison of 10,000 Consecutively Fired Cartridge 

Cases from a Model 22 Glock .40 S&W Caliber Semiautomatic Pistol‖, AFTE Journal, 

Volume 40, Number 1, Winter 2008, pp. 57-63.

Ten thousand (10,000) .40 S&W caliber cartridge cases fired from a Glock, model 

22, pistol were compared. All 10,000 fired cases could be identified to each other. 

This study validates previous durability studies that showed identifiable markings 

from a tool could persist for a long period of time.

Grooss, Klaus Dieter. ―The  ̳Hammer-Murderer.‘‖ AFTE Journal, vol. 27 (1), 1995, pp. 

27-30.

An actual murder case in Germany that in effect amounted to a blind test of both 

examiner skill and theoretical validity for cartridge case comparisons. A police 

officer was suspected of murder, but the lack of clues led to all Walther P5 pistols 

issued to police in Germany being test fired and compared to the evidence 

cartridge cases at the BKA lab. An identification occurred with a test-fired cartridge 

June 14, 2011 3434
case from the 3704th pistol. Almost simultaneous events elsewhere proved this 

conclusion to be accurate. No false identifications occurred.

Hamby J., and Thorpe J., ―The Examination, Evaluation and Identification of 9mm 

Cartridge Cases Fired from 617 Different GLOCK Model 17 & 10 Semiautomatic 

Pistols‖, AFTE Journal, Volume 41(4), Fall 2009, Pp. 310-324.

A study of cartridge cases fired from 617 different Glock pistols was conducted 

utilizing conventional comparative optical microscopy and electronic imaging 

technology to test the premise of individualization in FA/TM ID. Results of this 

study validated not only the premise of individualization but also the hypothetical 

proposition that a competent firearm and toolmark examiner can correctly identify 

the firearm that fired an ammunition component without committing a 

misidentification.

Kennington, Robert. ―Identification of Cartridge Cases Fired in Different Firearms:  ̳PreIdentified Cartridges.‘‖ AFTE Journal, vol. 31(1), 1999, pp. 15-19.

This research discusses the pitfall that toolmarks produced during the 

manufacturing process of ammunition components pose and that one should be 

mindful that these marks exist.

Lardizabal, P. ―Cartridge Case Study of the HK USP.‖ AFTE Journal, vol. 27 (1), Jan., 

1995, pp. 49-51.

This study examined two consecutively manufactured H&K 40 S&W caliber USP 

breechfaces. Subclass characteristics were identified on the breechface 

impressions. Test fired bullets from three H&K barrels were also examined and 

little correspondence was found between signatures from bullets fired from 

different barrels.

Lopez, Laura and Sally Grew. ―Consecutively Machined Ruger Bolt Faces.‖ AFTE 

Journal, vol. 32 (1), 2000, pp. 19-24.

This study warns that one should be careful with microscopic marks from a 

boltface machined with an end mill. Misidentification is possible unless the 

identification is based on wear or individual machining ―chatter‖ marks.

Lyons, D. J., ―The Identification of Consecutively Manufactured Extractors‖, AFTE 

Journal, Volume 41, Number 3, Summer, 2009, pp.246-256.

Study conducted on ten consecutively manufactured firearm extractors. Firearm 

and toolmark examiners from different laboratories were given ten sets of 

cartridge cases marked by these extractors to attempt to make the correct 

associations between the known and unknown cases. Each examiner also 

received twelve unknown marked cases in addition to the standards for the ten 

June 14, 2011 3535
consecutively manufactured extractors, with each known specimen having at least 

one unknown specimen associated with it. Study showed that extractors could be

distinguished from each other despite the fact they were consecutively 

manufactured and had subclass toolmarks on some surfaces.

Matty, William. ―Raven .25 Automatic Pistol Breech Face Tool Marks.‖ AFTE Journal, 

vol. 16 (3), 1984, pp. 57-60.

For this study, three consecutively made breechfaces from Raven pistols were 

compared. The concentric toolmarks on the breechfaces were found to be 

individual and not subclass.

Matty, William and Torrey Johnson. ―A Comparison of Manufacturing Marks on Smith & 

Wesson Firing Pins.‖ Journal of AFTE, vol. 16 (3), 1984, pp. 51-56.

This study examined the concentric marks produced by Smith & Wesson firing 

pins. Subclass characteristics were found. These subclass marks are a result of 

the lathe mounted cutter being much harder than the firing pins and thus marks 

can be reproduced; however, using the areas of the firing pins that show wear can 

be used for identification.

Rosati, Carlo. ―Examination of Four Consecutively Manufactured Bunter Tools.‖ AFTE 

Journal, vol. 32 (1), 2000, pp. 49-50.

For this study, four bunters produced by Electrical Discharge Machining (EDM) 

used by Remington for .45 Auto cartridge case manufacture were used to 

determine if this process was random in nature. Confirms random nature of marks 

from EDM process on headstamp characters.

Saribey, A. Y., Hannam A. G., Tarimci C., ―An Investigation into Whether or Not the 

Class and Individual Characteristics of Five Turkish Manufactured Pistols Change 

During Extensive Firing‖, Journal of Forensic Sciences, Volume 54, Number (5), 

September 2009, pp.1068-1072.

Conducted statistical durability study of fired cartridge cases from five different 

pistols. Each pistol had at least 1000 cartridge cases fired in them with every 

250th case compared to the first fired case. Although there were noted changes in 

individual and some class characteristics, these wear changes were not 

statistically significant based on standard deviation measurements. This study 

statistically validated previous durability studies.

Thompson, Evan. ―Phoenix Arms (Raven) Breechface Toolmarks.‖ AFTE Journal, vol. 

26 (2), 1994, pp. 134-135.

This is a follow-up study of the Matty article on Raven breechfaces. Four 

breechfaces from Phoenix pistols (formerly Raven) were compared to determine 

June 14, 2011 3636
the nature of their marks. As in the Matty article, the breechfaces were found to 

possess unique identifying marks.

Thompson, Evan. ―False Breechface ID‘s.‖ AFTE Journal, vol. 28 (2), April, 1996, pp. 

95-96.

This study examines the manufacturing process of Lorcin pistol breechfaces. Of 

noteworthiness is the fact that Lorcin breechfaces are stamped and then painted 

over, not machined. False identifications could be possible if the only marks 

considered are from the breechface. Also noted was the fact that paint on 

breechfaces has a tendency to chip off and that one should not solely rely on the 

breechface impression as a means for identification.

Uchiyama, T. ―Similarity among Breech Face Marks Fired from Guns with Close Serial 

Numbers.‖ AFTE Journal, Vol. 18, No. 3, 1986, pp. 15-52.

This study examined the breechface marks produced by Browning Baby, Raven 

P-25 and Titan pistols. Subclass characteristic were found to be significant on the 

breechface of each of these pistol models and examiners should use caution 

when encountering them.

TOOLMARK BIBLIOGRAPHY

Chumbly, L. Scott, et al, ―Validation of Tool Mark Comparisons Obtained Using a 

Quantitative, Comparative, Statistical Algorithm‖ Journal of Forensic Sciences, Volume 

55, Number 4, July 2010, Pp. 953-961.

A statistical analysis and computational algorithm for comparing pairs of toolmarks 

by profilometry data was conducted. Toolmarks produced by 50 sequentially made 

screwdrivers, at selected fixed angles, were analyzed both empirically by 

practicing examiners and by the established computational algorithms. The results 

of these comparisons, as well as a subsequent blind study with the practicing 

examiners, showed scores of good agreement between the algorithm and human 

experts. It was also noted that in some of the examination phases, examiner 

performance was much better than the algorithm.

Bachrach B., Jain A., Jung S., and Koons R.D., ―A Statistical Validation of the 

Individuality and Repeatability of Striate Tool Marks: Screwdrivers and Tongue and 

Groove Pliers‖, Journal of Forensic Sciences, Volume 55, Number 2, March 2010, pp 

348-357.

Study that statistically validated the original premise of individuality in Toolmark 

Identification by analyzing statistical distributions of similar values resulting from 

the comparison of Known Matches (KM) and Known Non-Matched (KNM) pairs of 

striated toolmarks. This quantifiable analysis of KM and KNM toolmark similarity 

distributions showed nearly error-free identifications.

June 14, 2011 3737
Bacharach, B., ―Statistical Validation on the Individuality of Tool Marks Due to the Effect 

of Wear, Environment Exposure and Partial Evidence‖, NIJ/NCJRS Document #227929, 

August, 2009.

An objective, quantifiable toolmark study on marks imparted onto wires by 

diagonal cutters. This study examined the effects of wear, environmental 

conditions and partial toolmark impressions by an automated 3-D system that 

mathematically correlated results of toolmarks to the tools that produced them. 

This study validated, and thus strengthened, the foundations of Toolmark 

Identification.

Burd, David Q. and Allen E. Gilmore. ―Individual and Class Characteristics of Tools.‖ 

Journal of Forensic Sciences, Vol. 13 (3), July, 1968, pp. 390-396.

This article discusses tools made from molds, such as die stamps and die 

forgings, and the possibility of confusing class marks as individual marks.

Butcher, S. and D. Pugh. ―A Study of Marks made by Bolt Cutters.‖ Journal of the 

Forensic Science Society, Vol. 15 (2), April 1975, pp. 115-126.

This study examines test marks made by ten consecutively made bolt cutters and 

ten randomly selected bolt cutters with ground working surfaces. The study 

determined that no more than 29% matching stria for known non-matches and 

between 87% and 93% matching stria for known matches. Implication: no risk of 

misidentification.

Cassidy, F. ―Examination of Toolmarks from Sequentially Manufactured Tongue and 

Groove Pliers.‖ Journal of Forensic Sciences, vol. 25 (4), Oct., 1980, pp. 796-809.

This study examines the individuality of striated marks produced by consecutively 

broach cut tongue and groove pliers. Examination of the jaw teeth and their test 

marks revealed no subclass marks and that the striated marks produced are 

individual to the tool that made them.

Clow, Charles M. ―Cartilage Stabbing with Consecutively Manufactured Knives: A 

Response to Ramirez v. State of Florida.‖ AFTE Journal, vol. 37 (2), Spring, 2005, pp. 

86-116.

This study utilized ten consecutively manufactured knives used in a stabbing 

motion to determine if the marks produced were unique and if marks were 

reproducible and identifiable in pig cartilage. Marks were found to be unique.

Marks reproduced and were found to be potentially identifiable in cartilage.

Eckerman, Stephanie J. ―A Study of Consecutively Manufactured Chisels.‖ AFTE 

Journal, vol. 34 (4), Fall 2002, pp. 379-390.

June 14, 2011 3838
In this study, consecutively belt sanded chisels were examined for the possibility 

of subclass marks. The marks were found to be individual to each chisel.

Flynn, Emmett M. ―Toolmark Identification.‖ Journal of Forensic Sciences, vol. 2 (1), 

Jan., 1957, pp. 95-106.

In this study, Chicago Police Crime Lab examined 100 consecutively made chisels 

finished with a grinding process. 5050 total comparisons made. No 

misidentifications.

Giroux B. N., ―Empirical and Validity Study: Consecutively Manufactured Screwdrivers‖, 

AFTE Journal, Volume 41, Number 2, Spring 2009, pp. 153-158.

The fundamental propositions of Toolmark Identification were tested with an 

empirical and validation study of five consecutively manufactured screwdrivers. 

The empirical study compared the machining marks imparted on the working 

surfaces of these screwdrivers to toolmark specimens produced by these 

screwdrivers. Eight qualified examiners at the FBI Laboratory participated in a 

blind validation study where eighty comparisons were conducted on the toolmarks 

produced by these screwdrivers. The results of this blind validity study resulted in

no mis-identifications and one mis-elimination.

Hall, J. ―Consecutive cuts made by bolt cutters and their effect on identification.‖ AFTE 

Journal, vol. 24 (3), July, 1992, pp. 260-272.

This study showed that consecutive cuts in lead with bolt cutters are identifiable,

showing that lead is a suitable material for test marks. Cuts in shackles may or 

may not change the tool, depending upon the hardness of the shackle.

Hornsby, B. ―MCC Bolt Cutters.‖ AFTE Journal, vol. 21 (3), July, 1989, p. 508.

This study randomly selected bolt cutters from the same production run. The 

working surfaces of the bolt cutters were produced through milling and tumbling.

The study concluded that, test marks produced by these bolt cutters were unique 

to the tool that made them. 

Jordan, Tom. ―Individual Characteristics on Copper Insulated Wire.‖ AFTE Journal, Vol. 

14 (1), 1982, pp. 53-56.

Using 3 to 6 inch sections of #12 insulated copper wire, this study revealed that 

the drawing marks are unique to the tool that produced them during manufacture.

Lee, Susan E. ―Examination of Consecutively Manufactured Slotted Screwdrivers.‖ 

AFTE Journal, vol. 35 (1), Winter, 2003, pp. 66-70.

June 14, 2011 3939
This study used five consecutively made screwdrivers to test the reproducibility of 

marks produced at various angles with both pushing and pulling motions. Each 

screwdriver‘s marks were found to be individual to tool that produced them.

Miller, Jerry and G. Beach, ―Toolmarks: Examining the Possibility of Subclass 

Characteristics,‖ AFTE Journal, Vol. 37 (4), Fall 2005, pp. 296-345.

This study utilizes consecutively manufactured diagonal cutting pliers, slip joint 

pliers, center punches, cold chisels and beveled wood chisels to determine if 

these tools possess subclass characteristics and individual characteristics. In all 

cases, except the center punches, subclass characteristics and individual 

characteristics were observed. The grinding process used to finish the punches 

produce individual characteristics only. The remaining tools produce marks that 

are easily identified based on individual characteristics or a combination of 

subclass and individual characteristics which are easily discernible.

Miller, Jerry. ―Cut Nail Manufacturing and Toolmark Identification.‖ AFTE Journal, Vol. 

30 (3), Summer 1998, pp. 492-498.

This study discusses the cut nail manufacturing process and a study was 

conducted in which 32,000 + nails were identified to the tools that made them.

Murdock, John E. ―The Individuality of Tool Marks Produced by Desk Staplers.‖ AFTE 

Journal, Vol. 6 (5), 1974. pp. 23-39.

This study found that Pilot brand staplers produced individual marks on staples, 

while Swingline brand staplers produced only subclass marks. The manufacturers 

used different manufacturing methods which was the reason for the differing types 

of marks.

Reitz, J. ―An Unusual Toolmark Identification case.‖ AFTE Journal, vol. 7 (3), Dec., 

1975, pp. 40-43.

Consecutively ground and randomly selected twist drill bits were studied. Results 

show no risk of misidentification. The grinding process caused no subclass 

influence.

Thompson, Evan and R. Wyant, ―Knife Identification Project (KIP),‖ AFTE Journal, Vol. 

35 (4), Fall 2003, pp. 366 – 370.

This study utilizes ten consecutively manufactured knives produced by the 

Benchmade Knife Corporation to produce a test to evaluate the uniqueness of 

striated toolmarks. One hundred and forty tests were distributed at the 2002 AFTE

Training Seminar. One hundred and three examiners submitted results for 

inclusion in the study. Of the possible 1,030 possible answers, 1,022 were correct 

June 14, 2011 4040
(8 incorrect answers). The error rate for this study was calculated to be 0.776 

percent.

Tuira, Y.J. ―Tire Stabbing with Consecutively Manufactured Knives.‖ AFTE Journal, Vol. 

14 (1), 1982, pp. 50-52.

Two consecutively made Buck knives were thrust into inflated tires and the 

toolmarks compared. The toolmarks were found to be significantly different.

Van Dijk, T.M. ―Steel Marking Stamps: Their Individuality at the Time of Manufacture.‖ 

Journal of the Forensic Science Society, Vol. 25 (4), July/Aug, 1985, pp. 243-253.

Fifty steel marking stamps made from the same hob (die) were examined for 

subclass marks. Unique defects from the hobbing process could be used to 

correctly identify each stamp.

Watson, D. ―The Identification of Toolmarks Produced From Consecutively 

Manufactured Knife Blades in Soft Plastics.‖ AFTE Journal, vol. 10 (3), September, 

1978, pp. 43-45.

This article discusses the uniqueness of two consecutively manufactured knives.

No carryover was found to exist between the two knives. 

Watson, Donald J., ―The Identification of Consecutively Manufactured Crimping Dies,‖ 

AFTE Journal, vol. 10, September 1978, pp. 19-21.

This study documents the manufacturing process of crimping dies and the results 

of the comparison of two consecutively manufactured crimping dies. It was found 

that the crimping dies bore no ―carry-over‖ effects and that lead seals crimped with 

these dies could be identified back to their source.

June 14, 2011 4141
11.What research exists that has examined the minimum set of skills a 

practitioner should possess in order to perform a specific task (e.g. pattern 

recognition and aptitude versus education)? 

Minimum Qualifications for Firearm and Toolmark Examiner Trainees (4/20/2006). 

Scientific Working Group for Firearms and Toolmarks.

http://www.swggun.org/swg/index.php?option=com_content&view=article&id=30:min

imum-qualifications-for-firearm-and-toolmark-examinertrainees&catid=10:guidelines-adopted&Itemid=6

This document is a guideline that addresses the minimum education requirements 

for individuals seeking employment as a firearm and toolmark examiner.

The Association of Firearm and Tool Mark (AFTE) Training manual.

The ATF National Firearms Training Academy (NFEA) -minimum educational

qualifications requirements

National Forensic Science Technology Center (NFSTC)- Firearm Examiner Training 

Program

June 14, 2011 4242
12.Are there any studies that use digital imaging to either validate or invalidate 

the basic tenets of firearm and toolmark comparisons? If so, what automated 

methods exist and how can they be refined? 

Chew, Wei et al (2010). Striation Density for Predicting The Identifiability of Fired Bullets 

With Automated Inspection Systems. Journal of Forensic Sciences, Vol. 55, No. 5, 

1222-1226.

Deinet, Werner. (1981). ―Studies of Models of Striated Marks Generated by Random 

Processes.‖ Journal of Forensic Sciences, Vol. 26 (1), pp. 35-50.

The author uses computer-aided studies of the degree of similarity of striated 

marks. He produced digitized images of 40 grinding marks which were entered

into a computer wherein position values were defined and idealized models were 

defined for an objective comparison of striated marks.

Evans, Paul & Smith, Clifton. (2004). ―Validation of the Linescan Imaging Technique for 

Imaging Cylindrical Forensic Ballistics Specimens.‖ AFTE Journal, Vol 36, No 4. pp 275-

280.

Abstract: The imaging of cylindrical surfaces of forensic ballistics specimens with 

an area camera system requires the geometric registration of a number of 

different images in order to effect a 360° view of its surface. This view is very 

difficult to achieve in terms of consistent spatial resolution. A line-scan imaging 

technique utilising an area array camera producing images of rotating ballistics 

specimens is described. A discussion of the validity of the technique to use the 

images for the identification of firearms is presented. The 2-D planar images of 

complete 3-D cylindrical surfaces produced by the linescan technique have a 

geometric format that is particularly suited to morphological image processing 

and the production of image databases.

Geradts, Zeno, et al. (2001). ―Pilot Investigation of Automatic Comparison of Striation 

Marks with Structured Light.‖ SPIE Proceedings Paper, Vol 4232. pp 49-56

Abstract: We have developed and tested an algorithm that can compare striation 

marks that are acquired with a standard camera and sidelight as well as 3Dinformation acquired with structured light. With six different screwdrivers test 

marks have been made with an angle of 45 degrees to the surface. These 

striation marks are moulded with gray silicon casting material. Then these marks 

are digitized with the structured light approach and with side light. For the 

structured light approach, it appeared that there are artifacts and variations in the 

image due to the number of stripes in the LCD projections and the camera 

resolution. We have compensated for these variations by averaging the lines 

over an area that is selected by the user. In the method that has been used for 

averaging, the slopes of the striae are followed. This method is also used for side 

light images to compensate for variations in the striation mark. In this research, 

June 14, 2011 4343
signatures of the tool marks are calculated then compared with a database of 

signatures by calculating the standard deviation of the difference. For the limited 

test set of six striation marks made with six different screwdrivers, the algorithm 

was able to distinguish the global shape of the screwdriver and the depth 

information itself. Since the images acquired with structured light contain more 

information on the toolmark itself, the correlation results were better than with 

side light images.

Intelligent Automation, Incorporated (October, 2010). A Statistical Validation of the 

Individuality of Guns Using High Resolution Topographical Images of Bullets. National 

Institute of Justice Grant #2006-DN-BX-K030.

Study of marks on fired bullets by a topography based (3D) automated system. 

This study continued the analysis of a previous 2005 NIJ bullet study and 

validated the original premise of Firearm/Toolmark ID. This study also concluded 

that 1) the ability to determine that a given bullet was fired from a specific barrel 

depends on the individual barrel itself and not only on the brand of its 

manufacture, and 2) the performance of the automated analysis system used in 

this study is not representative of that of a trained firearms examiner as humans 

have a remarkable ability to perform pattern matching that is difficult to be 

replicated in any automated system.

Leon, Fernando. (2006). ―Automated Comparison of Firearm Bullets.‖ Forensic Science 

International, Vol 156. pp 40-50.

Abstract: Fired bullets bear striation marks that can be thought of as a 

 ̳ ̳fingerprint‘‘ left by the firearm. This new comparison approach is based on an 

automated extraction of a  ̳ ̳signature‘‘ encompassing the relevant marks from an 

image. To this end, multiple pictures of the bullet are recorded first by using 

different illumination patterns, and a high quality image is generated by means of 

fusion techniques. After a preprocessing, the image intensities are filtered along 

the striations direction, yielding a compact representation of the marks. A nonlinear filter selects the striae of interest. The actual comparison takes place by 

cross correlating the signatures obtained this way. Finally, an assessment 

strategy is proposed to objectively evaluate the performance of the system. As 

demonstrated with an image database of real bullets, the proposed approach 

outperforms a state-of-the-art commercial system.

Miller, J., McLean, M. (1998). Criteria for Identification of Toolmarks. AFTE Journal, Vol. 

30, No.1, pp.15-61.

Using IBIS, the authors compared land impressions of .38 Special jacketed 

bullets fired from S&W revolvers. Found no CMS counts greater than six (6) for 

KNMs, using the computer monitor. Using a separate set of testfires and the 

comparison microscope, no CMS counts greater than four (4) for KNMs were 

found.

June 14, 2011 4444
Miller, J. (2000). Criteria for Identification of Toolmarks, Part II: Single Land Impression 

Comparisons. AFTE Journal, vol. 32 (2), Pp.116-131.

This study compares bullets fired by Raven 25 Auto, Lorcin 380 Auto, and 

Stallard Arms 9mm pistols to specimens in the NIBIN database. This study 

supports the Biasotti/Murdock Quantitative Conservative Matching Striae 

(QCMS) criteria. 

Smith, C. L. (2002). Linescan Imaging of Ballistics Projectile Markings for Identification. 

Security Technology Proceedings, 36th Annual International Carnahan Conference, pp. 

216 – 222.

The identification of firearms from forensic ballistics specimens is an exacting 

and intensive activity performed by specialists with extensive experience. The 

introduction of imaging technology to assist the identification process of firearms 

has enhanced the ability of forensic ballisticians to conduct analyses of these 

specimens for identification. The characteristic markings on the cartridge and 

projectile of a bullet fired from a gun can be recognised as a fingerprint for 

identification of the firearm. Forensic ballistics imaging has the capacity to 

produce high-resolution digital images of cartridge cases and projectiles for 

matching of crime scene specimens to test specimens. Projectile bullets fired

through the barrel of a gun will exhibit extremely fine striation markings, some of 

which are derived from minute irregularities in the barrel produced during the 

manufacturing process. The examination of these striations on the land marks 

and groove marks of the projectile is difficult using conventional optical 

microscopy. However, digital imaging techniques have the potential to detect the 

presence of striations on ballistics specimens for identification matching. This 

paper describes a linescan imaging technique to examine the striation markings 

on the land marks and groove marks of projectiles for positive identification. The 

paper discusses the application of the technique to cylindrical forensic ballistics 

specimens, and the potential of the technique for image matching. Digital images 

of land marks and groove marks of projectiles produced by the line scan 

technique are presented, and analyses of the images are conducted.

Smith, C.L. and Cross, J.M. (1995). ―Optical Imaging Techniques for Ballistics 

Specimens to Identify Firearms.‖ IEEE Proceedings: 29th Annual International Carnahan 

Conference on Security Technology. pp 275-289.

Abstract: Characteristic markings on the cartridge and projectile of a bullet are 

produced when a gun is fired. Over thirty different features within these markings 

can be distinguished, which in combination produce a ―fingerprint‖ for 

identification of a firearm. This paper describes an investigation into the 

development of an imaging system which can store, analyze, retrieve, and match 

high resolution digital images of cartridge cases. A computerized imaging system 

for ballistics identification will produce efficiencies in time and personnel, and 

June 14, 2011 4545
permit a more precise audit of firearms within a country. The project has 

produced good quality high resolution digitized images of cartridge cases. The 

development of the optical system to optimize image quality has been crucial for 

the image identification phase. By classifying cartridge image attributes, it is 

possible to store the unique ―signatures‖ of cartridge cases for identification. 

Appropriate image processing provides the signatures for the image library. The 

FIREBALL forensic ballistics interactive database incorporates a graphics user 

interface (GUI) to obtain precise ballistics metrics of cartridge case class 

characteristics. This project will significantly improve the effectiveness and 

efficiency of ballistics records and assist the tracing of firearms used in criminal 

activities by law enforcement agencies.

Smith, C.L. (2006). ―Profiling Toolmarks on Forensic Ballistics Specimens: An 

Experimental Approach.‖ IEEE Proceedings: 40th Annual International Carnahan 

Conference on Security and Technology. pp 281-286.

Abstract: This paper will discuss an experimental approach for matching toolmark 

images from the linescan technique and measurements from the profilometry 

technique of surface mapping. By relating the topography of a region on the 

surface of a cartridge case and projectile to that region on the unwrapped image 

from the linescan technique, a potential match may be developed. The 

application of depth profiling of imperfections on the projectiles and cartridges 

from the firing of a weapon has the potential to map unique markings on the 

ballistics specimens from crime scene firearms. The paper will show depth 

profiles of land marks and groove marks of projectiles, and firing pin marks and 

breach face marks on cartridges as examples supporting the potential for the 

profiling technique.

Zographos, A., et al. (1997). ―Ballistics Identification Using Line-Scan Imaging 

Techniques.‖ IEEE Proceedings: 31st Annual International Carnahan Conference on 

Security Technology. pp 82-87.

Abstract: A new line-scan imaging technique, well-suited to the inspection of 

ballistics specimens, is presented. The proposed system addresses a number of 

problems associated with the imaging of cartridge cases when conventional 

inspection techniques are used. This particular paper deals exclusively with 

imaging of the cylindrical surface of cartridge cases. Imaging of the firing pin 

marks on the end of the case is not considered. Results obtained so far from a 

prototype system are presented. It should be noted that this technique is still very 

much in its experimental phase and that as yet it has not been fully investigated 

for this forensic ballistics application.

Zhihu Huang; Jinsong Leng. (2010). ―An Online Ballistics Imaging System for Firearm 

Identification.‖ IEEE - 2

nd International Conference on Signal Processing Systems, Vol 

2. pp 68-72.

June 14, 2011 4646
Abstract: Since the traditional ballistics imaging system is dependent upon the 

expertise and experience of end-user, an intelligent ballistics imaging system is 

highly demanded to overcome the drawbacks of traditional techniques. This 

paper aims to develop a novel ballistics imaging system so as to combine the 

traditional functions with new features such as the line-scan image module, the 

characteristics extraction module, and the intelligent image processing module. 

With the help of these features, the new system can identify firearm more 

efficiently and effectively than the traditional techniques.

Zhihu Huang; Jinsong Leng. (2010). ―A Novel Binarization Algorithm for Ballistics 

Imaging Systems.‖ IEEE – 3

rd International Congress on Image and Signal Processing, 

Vol. 3. pp 1287 – 1291.

Abstract: The identification of ballistics specimens from imaging systems is of 

paramount importance in criminal investigation. Binarization plays a key role in 

preprocess of recognizing cartridges in the ballistic imaging systems. Unfortunately, 

it is very difficult to get the satisfactory binary image using existing binary algorithms. 

In this paper, we utilize the global and local thresholds to enhance the image

binarization. Importantly, we present a novel criterion for effectively detecting edges 

in the images. Comprehensive experiments have been conducted over sample 

ballistic images. The empirical results demonstrate the proposed method can 

provide a better solution than existing binary algorithms.

June 14, 2011 4747
13.What literature documents the automated methods of comparison that exist 

for firearms/toolmarks examination, how they are being applied to the 

examination process, and any potential shortcomings.

Bachrach, B. (2002). Development of a 3D-Based Automated Firearms Evidence 

Comparison System. Journal of Forensic Sciences, vol. 47 (6), 1253-1264.

Abstract: This study reports on a computerized system that calculates correlation 

coefficients for comparisons of bullet striation patterns using generated 3-D maps 

of bullet surfaces. Was validated using known matches (KMs) and known nonmatches (KNMs), so therefore the system arrives at a conclusion of identification 

(or not), with an associated probability of error. Highly relevant to our work, 

because it shows conclusively that an objective observer (a machine) detects 

significant visual differences between KNMs and KMs.

Bachrach, B. (et al). (2010). ―A Statistical Validation of the Individuality and Repeatablity 

of Striated Tool Marks: Screwdrivers and Tongue and Groove Pliers.‖ Journal of

Forensic Sciences, Vol 55, No. 2. pp 348-357.

Abstract: Tool mark identification relies on the premise that microscopic 

imperfections on a tool‘s working surface are sufficiently unique and faithfully 

transferred to enable a one-to-one association between a tool and the tool marks 

it creates. This paper presents a study undertaken to assess the validity of this 

premise. As part of this study, sets of striated tool marks were created under 

different conditions and on different media. The topography of these tool marks 

was acquired and the degree of similarity between them was quantified using 

well-defined metrics. An analysis of the resulting matching and nonmatching 

similarity distributions shows nearly error-free identification under most 

conditions. These results provide substantial support for the validity of the 

premise of tool mark identification. Because the approach taken in this study 

relies on a quantifiable similarity metric, the results have greater repeatability and 

objectivity than those obtained using less precise measures of similarity.

Blackwell, R.J., and Framan E.P. (1980). ―Automated Firearms Identification System 

(AFIDS): Phase I. AFTE Journal, Vol. 12, No. 4. pp 11-37. (Reprinted in AFTE Journal –

original article was prepared by the authors of the Jet Propulsion Laboratory for the 

Applications Technology Office, National Aeronautics and Space Administration)

Abstract: Items critical to the future development of an automated firearms 

identification system (AFIDS) have been examined, with the following results: 1. 

Types of objective data, that can be utilized to help establish a more factual basis 

for determining identity and nonidentity between pairs of fired bullets, have been 

identified. 2. A simulation study has indicated that randomly produced line, 

similar in nature to the individual striations on a fired bullet, can be modeled and 

that random sequences, when compared to each other, have predictable 

relationships., 3. A schematic diagram of the general concept for AFIDS has 

June 14, 2011 4848
been developed and individual elements of this system have been briefly tested 

for feasibility., Future implementation of such a proposed system will depend on 

such factors as speed, utility, projected total cost and user requirements for 

growth. The success of the proposed system, when operational, would depend 

heavily on existing firearms examiners.

Chu, Wei, et al. (2010). Pilot Study of Automated Bullet Signature Identification Based 

on Topography Measurements and Correlations. J Forensic Sci, Vol 55, No 2, 1-7.

Abstract: The authors outline a procedure for automated bullet signature 

identification based on topography measurements using confocal microscopy 

and correlation calculation. The correlation results show a 9.3% higher accuracy 

rate compared with a currently used commercial system based on optical 

reflection.

De Kinder, Jan and Bonfanti, Monica. (1999). ―Automated Comparisons of Bullet 

Striations Based on 3D Topography.‖ Forensic Science International, Vol 101. pp 85-93.

Abstract: A system capable of comparing the signatures on bullets in the field of 

firearms identification is presented. It is based on the recording of the topography 

of a bullet using laser profilometry. A procedure to derive a one-dimensional 

array of characteristics out of the recorded data is presented. These so-called 

feature vectors are compared with similar quantities from other bullets using a 

correlation technique. Good results were obtained for weapons leaving welldefined characteristics.

Dongguang, L. (2006). Ballistics Projectile Image Analysis for Firearm Identification. 

IEEE Transactions on Image Processing, Vol 15, No. 10, 2857-2865.

Abstract: The author proposes a new analytic system based on the fast Fourier 

transform for identifying projectile specimens by the line-scan imaging technique. 

His paper develops optical, photonic, and mechanical techniques to map the 

topography of the surfaces of projectiles for the purpose of identification.

Dongguang, L.. (2009). ―Ballistics Image Processing and Analysis for Firearms 

Identification.‖ Image Processing. Chapter 9, pp 141-174. ISBN: 978-953-307-026-1.

A chapter in the book ―Image Processing‖ in which the author discusses linescan imaging techniques of firearm related evidence (bullet and cartridge cases) 

coupled with a new analytic technique of Fast Fourier Transform. The system 

gives an approach for projectile capturing, storing, and automatic analysis and 

makes a significant contribution towards the efficient and precise identification of 

projectiles.

June 14, 2011 4949
Jacque-Mann, M. and Espinoza, E. (1992). ―Firearms Examination by Scanning 

Electron Microscopy: Observations and an Update on Current and Future Approaches.‖ 

AFTE Journal, Vol. 24, No. 3. pp 294-303.

Abstract: The use of scanning electron microscopy (SEM) in the examination of 

firearms evidence was introduced in the literature over twenty years ago. Due to 

cost and convenience factors, however, scanning electron microscopy has 

remained largely inaccessible and therefore under-exploited in the firearms 

community. We will review the significant advantages of SEM in the examination 

of firearms evidence and present information on recent and future improvements 

in methodology which make this approach more attractive and available to 

forensic laboratories.

Jones, B.C., Press, M., and Guerci, J.R. (1998). ―Decision Fusion Based Automated 

Drill Bit Correlator.‖ SPIE Conference on Investigation and Forensic Science 

Technologies: SPIE, Vol. 3576. pp 253-263.

Abstract: This paper describes a recent study conducted to investigate the 

reproducibility of toolmarks left by drill bits. This paper focuses on the automated 

analysis aspect of the study, and particularly the advantages of using decision 

fusion methods in the comparisons. To enable the study to encompass a large 

number of samples, existing technology was adapted to the task of automatically 

comparing the test impressions. Advanced forensic pattern recognition 

algorithms that had been developed for the comparison of ballistic evidence in 

the DRUGFIRETM system were modified for use in this test. The results of the 

decision fusion architecture closely matched those obtained by expert visual 

examination. The study, aided by the improved pattern recognition algorithm, 

showed that drill bit impressions do contain reproducible marks. In a blind test, 

the DRUGFIRE pattern recognition algorithm, enhanced with the decision fusion 

architecture, consistently identified the correct bit as the source of the test 

impressions.

Miller, J. (2000). Criteria for Identification of Toolmarks, Part II: Single Land 

Impression Comparisons. AFTE Journal, vol. 32 (2), 116-131.

Abstract: This study compares bullets fired by Raven 25 Auto, Lorcin 380 Auto, 

and Stallard Arms 9mm pistols to specimens in the NIBIN database. This study 

supports the Biasotti/Murdock Quantitative Conservative Matching Stiae (QCMS)

criteria. 

Senin, Nicola, et al. (2006). ―Three-Dimensional Surface Topography Acquisition and 

Analysis for Firearm Identification.‖ Journal of Forensic Sciences, Vol. 51, No. 2. pp 

282-295.

Abstract: In the last decade, computer-based systems for the comparison of 

microscopic firearms evidence have been the subject of considerable research 

June 14, 2011 5050
work because of their expected capability of supporting the firearms examiner 

through the automated analysis of large amounts of evidence. The Integrated 

Ballistics Identification System, which is based on a two-dimensional 

representation of the specimen surface, has been widely adopted in forensic 

laboratories worldwide. More recently, some attempts to develop systems based 

on three-dimensional (3D) representations of the specimen surface have been 

made, both in the literature and as industrial products, such as BulletTRAX-3D, 

but fundamental limitations in achieving fully automated identification remain. 

This work analyzes the advantages and disadvantages of a 3D-based approach 

by proposing an approach and a prototype system for firearms evidence 

comparison that is based on the acquisition and analysis of the 3D surface 

topography of specimens, with particular reference to cartridge cases. The 

concept of 3D virtual comparison microscope is introduced, whose purpose is not 

to provide fully automated identification, but to show how the availability of 3D 

shape information can provide a whole new set of verification means, some of 

them being described and discussed in this work, specifically, visual 

enhancement tools and quantitative measurement of shape properties, for 

supporting, not replacing, the firearm examiner in reaching the final decision.

Smith, C. and Li, Dongguang. (2008) ―Intelligent Imaging of Forensic Ballistics 

Specimens for ID.‖ IEEE Proceedings: Congress on Image and Signal Processing, Vol 

3. pp 37-41.

Abstract: The paper describes some of important technologies in firearm 

identification using forensic ballistics specimens. The mapping of micro-surfaces 

on regions on the specimens for comparison to establish identification according 

to the precision of measurement of the features has been proposed. The physical 

techniques of linescan, laser depth proofing, and photonic 3D topography can be 

developed into future tools for forensic ballisticians for identification of cartridge 

cases and projectiles.

Uchiyama, Tsueno. (1988). ―Automatic Comparison Model of Land Marks.‖ AFTE 

Journal, Vol. 20, No. 3. pp 252-258.

Abstract: In the comparison of fired bullets, examiners compare the contour of 

the bullet surfaces using a comparison microscope. There can be much 

information on the surfaces of fired bullets that is related to the gun bore surface 

through which bullets are fired. However, one cannot expect that all of the bore 

surface characteristics will be reproducibly transferred; even on consecutively 

fired bullets it may not be possible. Also, there are always many extraneous 

markings on fired bullet surfaces which are not representative of the gun bore 

surface and which the examiner must learn to distinguish and ignore as useless 

information. Usually, a comparison microscope examination of a pair of fired 

bullets requires more than 20 minutes before the examiner can form an opinion 

as to identity or non-identity. In some cases, such an examination requires up to 

one week. In this paper, the bullet comparison process conducted by the 

June 14, 2011 5151
examiner was analyzed in order to see if any of this manual process could be 

replaced or assisted by the use of a computer.

Uchiyama, Tsueno. (1993). ―Automated Landmark Identification System.‖ AFTE 

Journal, Vol 25, No. 3. pp 172-196.

Abstract: We have developed the Automated Landmark Identification System 

(ALIS). This system handles the images of the striae in the landmarks on fired 

bullets through a CCD camera. First, image processor calculate the histogram of 

intensity of an image from the CCD camera. Then a personal computer converts 

the histogram data into "bar code" like stripes. These "bar code" and histogram 

data are compared to any other similarly recorded and stored data. In

comparison process, the data of the landmark with the narrower width is moved 

from left to right, and the percent match of striae, sum of square between 

histograms of image data and sum of depth of matching striae are calculated for 

each shift in position. The maximum number of consecutively matched striae is 

also counted for each shift in position. From the fluctuating pattern of these 

calculated parameters, the reliability of the positive conclusion can be calculated.

June 14, 2011 5252
14. What studies exist regarding the use of databases to facilitate an automated 

approach to analysis?

Bachrach, B. (2000). ―Ballistic Matching Using 3D Images of Bullets and Cartridge 

Cases: Project Summary.‖ National Institute of Justice Grant Award Number 97-LBVX-0008.

Abstract/Results of Study: To determine the feasibility of using 3D information 

from a bullet‘s surface to improve the matching rate of existing automated search 

and retrieval systems, it was required to develop and implement all the elements 

of an acquisition component. Furthermore, this particular acquisition component 

would operate based on 3D captured data, as opposed to 2D captured data. 

Together with the acquisition component, a preliminary version of a correlation 

component was developed in order to verify the usefulness of the 3D captured 

data. The complete automated search and retrieval system was tested through a 

number of independent evaluations. Among these evaluations, we have 

performed a number of so-called ―blind tests.‖ For these blind tests, we were 

provided with control bullets from different guns (i.e., we were told which gun 

fired each of the ―control bullets‖), and with questioned bullets. The task was to 

identify which gun fired each of the questioned bullets based on the data 

obtained from the control bullets. In all cases the system was able to perform in a 

very satisfactory manner, making very few mistakes in the identification of which 

gun fired each of the questioned bullets. As a direct result of the research done 

under this project we have developed a fully functional prototype of the 3D 

ballistic analysis system (named SCICLOPs). 

Baldwin, D., Morris, M., Bajic, S., Zhou, Z., Kreise, M. J. (April 2004). Statistical Tools 

for Forensic Analysis of Toolmarks. Ames Laboratory, USDOE Office of Science, IS5160.

Recovery and comparison of toolmarks, footprint impressions, and fractured 

surfaces connected to a crime scene are of great importance in forensic science. 

The purpose of this project is to provide statistical tools for the validation of the 

proposition that particular manufacturing processes produce marks on the workproduct (or tool) that are substantially different from tool to tool. The approach to 

validation involves the collection of digital images of toolmarks produced by 

various tool manufacturing methods on produced work-products and the 

development of statistical methods for data reduction and analysis of the images.

The developed statistical methods provide a means to objectively calculate a 

"degree of association" between matches of similarly produced toolmarks. The 

basis for statistical method development relies on "discriminating criteria" that 

examiners use to identify features and spatial relationships in their analysis of 

forensic samples. The developed data reduction algorithms utilize the same rules 

used by examiners for classification and association of toolmarks.

June 14, 2011 5353
Banno, Atsuhiko, et al. (2004). Three Dimensional Visualization and Comparison of 

Impressions on Fired Bullets. Forensic Science International, 140, pp 233-240.

In this study, the authors focused on 3D geometric data of landmark impressions 

on fired bullets for identification. They presented an algorithm for a shape 

comparison of impressions on bullets. They were concerned only with 

visualization and comparison and not identification. However, the authors feel 

the most important future work regarding this method is the identification phase 

which would require the comparison of numerous pairs of bullets to determine 

the rigid threshold.

Banno, Atsuhiko. (2004). ―Estimation of Bullet Striation Similarity Using Neural 

Networks.‖ Journal of Forensic Sciences, Vol 49, No 3. pp 1-5.

Abstract: A new method that searches for similar striation patterns using neural 

networks is described. Neural networks have been developed based on the 

human brain, which is good at pattern recognition. Therefore, neural networks 

would be expected to be effective in identifying striated toolmarks on bullets. The 

neural networks used in this study deal with binary signals derived from striation 

images. This signal plays a significant role in identification, because this signal is 

the key to the individuality of the striations. The neural network searches a 

database for similar striations by means of these binary signals. The neural 

network used here is a multilayer network consisting of 96 neurons in the input 

layer, 15 neurons in the middle, and one neuron in the output layer. Two signals 

are inputted into the network and a score is estimated based on the similarity of 

these signals. For this purpose, the network is assigned to a previous earning. To 

initially test the validity of the procedure, the network identifies artificial patterns 

that are randomly produced on a personal computer. The results were 

acceptable and showed robustness for the deformation of patterns. Moreover, 

with ten unidentified bullets and ten database bullets, the network consistently 

was able to select the correct pair.

Bolton-King, Rachel S. et. al. (2010). What are the Prospects of 3D Profiling Systems 

Applied to Firearms and Toolmark Identification? AFTE Journal, Vol 42, No 1, 23 – 33.

This article concluded that focus-variation microscopy has potentially the most 

promising approach for a forensic laboratory instrument, in terms of functionality 

and 3D imaging performance, and is worthy of further investigation.

De Kinder, Jan, et al. (1998). ―Surface Topology of Bullet Striations: An Innovating 

Technique.‖ AFTE Journal, Vol. 30, No. 2. pp 294-299.

Abstract: Laser topography is presented as a way to obtain characteristic 

information of the striation marks on bullets. A profilometer, equipped with a 

translational and rotational stage, is used tor this purpose. Using the translational 

stage, the parameters of the system were optimized and one groove on a 9mm 

June 14, 2011 5454
Para bullet was studied. The correspondence between our results and light 

microscopy is shown. The first results of measurements of the whole 

circumference of a bullet using the rotational stage promise a potential 

application in the field of firearms and tool marks identification.

De Kinder, Jan. (2002). ―Ballistic Fingerprinting Databases.‖ Science & Justice, Vol 42, 

No. 4. pp 197-203

Abstract: This article discusses a number of questions regarding the setting up of 

ballistic fingerprinting databases, consisting of ammunition components fired by 

all the firearms held in legal possession. These questions can be classified into 

three categories--the efficiency of the database, forensic issues, and practical 

issues to be dealt with. The current New York State legislation is used as an 

illustration of the choices to be made when setting up a ballistic fingerprinting 

database. Three important arguments are formulated against the installation of a 

ballistic fingerprinting database.

Demoli, N. et al. (2004). Toolmarks Identification using SEM Images in an 

Optoelectronic Correlator Device. Optik, Vol 115, No. 11, pp. 487-492.

The authors propose a method for identifying toolmarks by utilizing an 

optoelectronic correlator device as a possible solution. The effectiveness of the 

proposed approach is demonstrated by the results of the identification of marks 

on wires by lap joint pliers. Since this method combines fast optical processing 

and digital image information, the proposed method can be automated.

George, W. (2004). ―A Validation of the Brasscatcher Portion of the NIBIN/IBIS System.‖

AFTE Journal, Vol. 36, No. 4. pp 286-288.

Abstract: A study was conducted using over 500 cartridge casings fired in Smith 

& Wesson1⁄2 .40 S&W caliber pistols and entered into the BRASSCATCHER 

portion of IBIS. Entries were made using Remington1⁄2 and Federal1⁄2 ammunition 

and the study examined the ability of IBIS to match these cartridge casings. The 

results of this study raise the issue of limiting the viewable correlation results to 

the top 20% of the entries in the database

George, W. (2004). ―The Validation of the Brasscatcher Portion of the NIBIN/IBIS 

System Part Two: Fingerprinting Firearms Reality or Fantasy.‖ AFTE Journal, Vol. 36, 

No. 4. pp 289-296.

Abstract: A study of the Brasscatcher portion of the NIBIN/IBIS system was 

conducted using a database of 850 cartridge cases fired in Smith & Wesson .40 

S&W caliber pistols. Correlations were generated for entries from Federal, 

Winchester and Remington brand ammunition and a study to locate the 

placement of matching cartridge cases initiated. Forensic Technology was able 

to open the entire database for viewing instead of the normal user field of 20 %. 

June 14, 2011 5555
This study provided a real test of the ability of Brasscatcher to identify cartridge 

cases fired from similar firearms, and addresses the concept of fingerprinting 

firearms for use in criminal investigations. During this study an additional 

advantage regarding the second breech face impression image was revealed. 

The second image is not used for correlation purposes.

Geradts, Zeno, et al. (1994). A New Approach to Automatic Comparison of Striation 

Marks. Journal of Forensic Sciences, Vol. 39, No 4, pp. 974-980.

The authors created a database for toolmarks named TRAX using a PC. The 

database is filled with video images and administrative data about the toolmarks. 

The authors also developed an algorithm for the automatic comparison of 

digitized striation patterns. The system works well for deep and complete 

striation marks which will be implemented in TRAX.

Geradts, Z. et al. (1999). ―Pattern Recognition in a Database of Cartridge Cases.‖ SPIE 

Proceedings: Investigation and Forensic Science Technologies, Vol. 3576. pp 104-115.

Abstract: On the market several systems exist for collecting spent ammunition for 

forensic investigation. These databases store images of cartridge cases and the 

marks on them. The research in this paper is focused on the different methods of 

feature selection and pattern recognition that can be used for comparison. For 

automatic comparison of these images it is necessary to extract firstly the useful 

parts of the images. On databases of 2000 images several preprocessing steps 

have been tested and compared. The results and methods, which have been 

implemented, are presented.

Giverts P., Springer E., and Argaman U., Using the IBIS for the Examination of Bullets 

Fired from Polygonally Barreled Guns Such as the Glock Pistol, AFTE Journal, Volume 

36, Number 3, Summer 2004, pp 226-229.

Polygonally rifled barreled handguns have enjoyed much popularity and have 

become widespread in recent years. However, as of now, the IBISÖ is not too 

efficient in searching polygonal bullets. Thus, there is now all the more need for 

one to be able to successfully handle, in the IBISÖ, bullets fired from such. This 

paper describes and suggests a possible solution for enabling the IBISÖ to 

successfully handle such bullets.

Kong, Jun, et al. (2003). A Firearm Identification System Based on Neural Network. AI 

2003: Advances in Artificial Intelligence; Lecture Notes in Computer Science, Vol. 2903, 

pp.315-326.

The authors present a firearm identification system based on Self-Organizing 

Feature map (SOFM) neural network. The experiments performed showed the 

model proposed has high performance and robustness by integrating the SOFM 

neural network and the decision-making strategy. The model also will make a 

June 14, 2011 5656
significant contribution towards the further processing, such as the more efficient 

and precise identification of cartridge cases by combination with more 

characteristics on cartridge case images.

Kong, Jun, et al. (2004). An Automatic Analysis System for Firearm Identification Based 

on Ballistics Projectiles. Rough Sets and Current Trends in Computing; Lecture Notes in 

Computer Science, Vol 3066, Pp. 653-658.

Over 30 different features within the marks left on bullets and projectiles can be 

distinguished which in combination produce a ―fingerprint.‖ The authors present 

a means of automatically analyzing features within a firearm ―fingerprint‖ where it 

is possible to identify not only the type and model of a firearm, but also each 

individual weapon. A new analytic system based on fast Fourier transform (FFT) 

for identifying the projectile specimens digitized using the line-scan imaging 

technique. Experimental results show that the proposed system has the ability of 

efficient and precise analysis and identification for projectiles specimens.

Kou, Chenyuan and Tung, Cheng-Tan. (1994). ―FISOFM: Firearms Identification Based 

on SOFM Model of Neural Network.‖ Proceedings – Institute of Electrical and 

Electronics Engineers – 28th Annual International Carnahan Conference on Security 

Technology. pp 120-125.

Abstract: Firearms Identification (F1) has been getting serious and tremendous in 

crime investigation for the last two decades. We propose a solution to Fl in 

Neural Network (NN) technology. There are lots of methods have been using in 

FI such as extractor mark, breach mark, ejector mark, and chambering mark 

identification, etc. We choose the chambering mark identification as our method 

in this research. It is the simple and useful method for crime investigation. 

Because of the principle of tool mark, we may identify the firearms. The 

chambering mark needs to be scanned, preprocessed, segmented, described, 

reduced and enhanced the noise pattern, and will be recognized its individual 

characteristic via the Self Organizing Feature Map(S0FM) model of NN. lt really 

eases the burden of Forensic Laboratory's technicians, because they do not 

need to Identify the tool mark via microscope, instead of using Neural Network 

technology of Artificial Intelligence to identify firearms.

Peterson, J.L., (1974). Utilizing the Laser for Comparing Tool Striations. Journal of 

Forensic Sciences., Vol. 14, No 1, pp. 57-62.

The author describes a method for examining the contour of striated tool marks 

by focusing laser light on the tool striations moving at a constant rate. The 

graphical representations of the reflected light may be used to compare tool 

marks without utilizing a comparison microscope, however the author determined 

that the system would require refinement prior to its regular utilization in a 

forensic science laboratory.

June 14, 2011 5757
Robinson, M. et al. (1998). ―Ballistics Imaging – Latest Developments.‖ IEEE 

Proceedings: 32nd Annual International Carnahan Conference on Security Technology. 

Pp 181-183.

Abstract: This paper outlines the latest developments concerning a forensic 

imaging system that uses a CCTV camera in a line-scan mode for the inspection 

of bullet specimens placed on a rotating platform. Specifically, line-scan images 

obtained from the cylindrical sides of fired rounds including both projectiles and 

cartridge cases plus firing pin marks are discussed. Ultimately, it is anticipated 

that this research will lead to the development of a forensic imaging application 

from which a data base can be built to automatically match different bullet 

specimens in much the same way as a fingerprint data base is operated.

Smith, C. (1997). ―Fireball: A Forensic Ballistics Imaging System.‖ Institute of Electrical 

and Electronic Engineers Proceedings: 31st Annual International Carnahan Conference 

on Security Technology. pp 64-70.

Abstract: Characteristic markings on the cartridge and projectile of a bullet are 

produced when a gun is fired. Over thirty different features within these markings 

can be distinguished, which in combination produce a ―fingerprint‖ for 

identification of a firearm. This paper will describe an investigation into the 

development of an imaging system for Police Services which can store, analyse, 

retrieve, and match high resolution digital images of cartridge cases. A 

computerised imaging system for ballistics identification will produce efficiencies 

in time and personnel, and permit a more precise audit of firearms within a 

country. The project has produced good quality high resolution digitised images

of cartridge cases for the identification function. The development of the optical 

system to optimise image quality has been crucial for the image identification 

phase. By classifying cartridge image attributes, it is possible to store the unique 

―signatures‖ of cartridge cases for identification. Appropriate image processing 

provides the signatures for the image library. The Fireball forensic ballistics

interactive database incorporates a Graphics User Interface (GUI) to obtain 

precise ballistics metrics of cartridge case class characteristics. Features of the 

Fireball forensic ballistics database will be presented, together with a description 

of the major applications of this ballistics imaging system.

Thompson, R., et al. (1996). ―Computerized Image Analysis for Firearms Identification; 

The Integragted Ballistic Identification System (IBIS) BRASSCATCHER Performance 

Study.‖ AFTE Journal, Vol. 28, No. 3. pp 194-203

Abstract: The Bureau of Alcohol, Tobacco and Firearms (ATF) San Francisco 

Laboratory Center has conducted a Performance Study of the IBIS 

BRASSCATCHER hardware and software used in acquiring and correlating 

breech face and firing pin impressions on expended cartridge casings. Pairs of 

casings from over 200 pistols representing .25, .380, 9mm, .45 calibers were 

June 14, 2011 5858
correlated. There was no microscopic pre-screening of the cartridge casings prior 

to selection for testing. The correct "twin" casing was found in the first position of 

ranked scores between 58 to 78 percent of the time, and 74 to 93 percent of the 

time in the top five positions. The correct "twin" casing was found in the first 

position 94 percent of the time for a Glock 9mm caliber pistol database. Visual 

subjective estimations of cartridge casing "matchability" show that images judged 

"good" and "fair" in quality constituted the bulk of "first position " matches 

selected by the computer. However, a sizeable number of "poor" quality images 

of matching casings were still found in the top scoring position.

Uchiyama T., Toolmark Reproducibility on Fired Bullets and Expended Cartridge 

Cases, AFTE JournaL, Volume 40, No. 1, Winter, 2008, pp. 3-46 

The reproducibility of landmarks, breechface marks and firing pin marks on one 

hundred successively fired bullets and cartridge cases were examined. Three 

types of Speer brand, one of Remington brand and one of DFA brand frangible 

cartridges were fired in a semi-automatic pistol. Remarkable differences were 

observed in the general appearance of the landmarks, breechface marks and 

firing pin marks which were impressed on the different brands of cartridges, even 

when consecutively fired. Identification of the landmarks between bullets from 

different brands of cartridges was difficult because their general appearance 

differed greatly. Difference in bullet diameters was found to be a major cause of 

changes in landmarks among different manufacturer's bullets. Although the depth 

and number of striations decreased gradually, reproducibility of breechface 

marks on the primers of cartridges was rather good. The diameter of firing pin 

indentations also differed among different brands of cartridges. Although the 

reproducibility of the diameter of circular lines on firing pin indentations was 

good, the detail in these circular lines fluctuated a great deal. Quantitative CMS 

was used as a means of critically evaluating and communicating the extent of 

striated pattern agreement among the rifling impressions on the fired bullets in 

this study.

June 14, 2011 5959
15.Does research exist that supports the “comparative” nature of 

firearms/toolmarks examinations versus “blind” analysis of known and 

unknown (e.g. documentation of features and then comparing the resuls)? 

Does research exist which identifies how and which cognitive factors impact 

the analysis process?

Balthazard, V. (2004). ―Identification of Projectiles from Firearms.‖ AFTE Journal, Vol.

36, No. 3. Pp 219-225. (REPRINT from Identification de Projectiles d‘Armes a Feu. 

Archives d‘Anthropologie Criminelle. Vol. 28 (1913), pp 421-433.

Foundational article in the field of firearm and tool mark identification in which the 

author establishes the general criteria and procedure/processes for determining 

an identification between two items. The author uses photography as his method 

of determining an identification as this article predates the advent of the 

comparison microscope.

Bunch, S. (et al). (2009). ―Is a Match Really a Match? A Primer on the Procedures and 

Validity of Firearm and Toolmark Identification.‖ Forensic Science Communications, Vol. 

11, No. 3. pp 1-10.

Abstract: The science of firearm and toolmark identification has been a core 

element in forensic science since the early 20th century. Although the core 

principles remain the same, the current methodology uses validated standard 

operating procedures (SOPs) framed around a sound quality assurance system. 

In addition to reviewing the standard procedure the FBI Laboratory uses to 

examine and identify firearms and toolmarks, we discuss the scientific foundation 

for firearm and toolmark identification, the identification criterion for a "match," 

and future research needs in the science.

Burd, D. and Kirk, P. (1942). ―Tool Marks. Factors Involved in Their Comparison and 

Use as Evidence.‖ Journal of Criminal Law and Criminology, Vol. 32, No. 6. pp 679-686.

Text from Article: Comparison of tool marks as an aid in the solution of crime is a 

well known and widely used procedure which is generally considered as yielding 

valid court evidence. It is true; nevertheless, that much misapprehension exists 

as to the individuality of such marks and the probability of repetition of a mark by 

more than one tool. Such misapprehension as exists has undoubtedly arisen in 

part from a lack of careful study of the factors which influence the character of 

the marks left by a tool, and which must be considered in the identification of 

such marks. In view of the great difficulty of obtaining at any time an absolutely 

perfect match of the striations making up a tool mark of the friction type, it is of 

crucial importance to determine what degree of identity must be established 

before it can be stated that two marks were made by the same tool.

Gunther, C. O. (1932). ―Markings on Bullets and Shells Fired from Small Arms. 

Mechanical Engineering, Vol. 54. pp 341-345.

June 14, 2011 6060
AND

Gunther, C. O. (1930). ―Markings on Bullets and Shells Fired from Small Arms. 

Mechanical Engineering, Vol. 52. pp 107-118 and 1065-1069.

AND

Gunther, C.O. (1932). ―Principles of Firearms Identification: Further Analysis of 

Accidentical Characteristics.‖ Army Ordnance, Vol. 13. pp 40-43.

AND

Gunther, C.O. (1932). ―Principles of Firearms Identification: Fingerprinting Ordnance in 

the War on Crime.‖ Army Ordnance, Vol. 12. pp 339-340.

In this series of articles the author explores the application of science to firearm 

and toolmark examination. He establishes the processes of comparison of 

evidence from both a class and individual basis. He further describes the 

techniques of photography and microscopy and how to utilize these techniques 

during a comparison examination. These articles are foundational for the field of 

firearm and toolmark identification.

Itiel E. Dror, Christophe Champod, Glenn Langenburg, David Charlton, Heloise Hunt, 

Robert Rosenthal, Cognitive issues in fingerprint analysis: Inter- and intra-expert 

consistency and the effect of a  ̳target‘ comparison

Deciding whether two fingerprint marks originate from the same source requires 

examination and comparison of their features. Many cognitive factors play a 

major role in such information processing. In this paper we examined the 

consistency (both between- and within-experts) in the analysis of latent marks, 

and whether the presence of a  ̳target‘ comparison print affects this analysis. Our 

findings showed that the context of a comparison print affected analysis of the 

latent mark, possibly influencing allocation of attention, visual search, and 

threshold for determining a  ̳signal‘. We also found that even without the context 

of the comparison print there was still a lack of consistency in analysing latent 

marks. Not only was this reflected by inconsistency between different experts, 

but the same experts at different times were inconsistent with their own analysis. 

However, the characterization of these inconsistencies depends on the standard 

and definition of what constitutes inconsistent. Furthermore, these effects were 

not uniform; the lack of consistency varied across fingerprints and experts. We 

propose solutions to mediate variability in the analysis of friction ridge skin.

Kellett, PM, Individualization: Principles and Procedures in Criminalistics Laboratory 

Director, San Bernardino County Sheriff's Department, CA 

The author's stated purpose in writing this text is to identify and discuss first 

principles common to all comparisons and individualizations. The material 

presented grew out of ―Forensic Identification‖ taught at Ontario Police College. 

The author writes in a style suitable for students, trial attorneys and criminalists. 

The book is well-referenced (128 footnotes) and contains an index.

June 14, 2011 6161
Osterburg, James W. (1969). ―The Evaluation of Physical Evidence in Criminalistics: 

Subjective or Objective Process?‖ Journal of Criminal Law and Criminology, Vol. 60, 

No. 1. pp 97-101.

The author discusses the role statistics might play in establishing 

identify/identification as well as the current state of firearms identification in 

determining when individualization has occurred. 

Thornton, J. (1979). ―The Validity of Firearms Evidence.‖ AFTE Journal, Vol. 11, No. 2. 

pp 16-19. (Reprint from Forum July/August 1978).

The author discusses the nature of the comparison process in firearms 

identification. He further delves into the concept of objective criteria for the 

practice of firearms identification. He establishes what processes are objective 

and what processes are subjective in the comparison of two items of evidence.

Tuthill, H., and George, G. (1994). Principles and Procedures in Criminalistics, 

Lightening Powder Company

This book not only defines the steps of Analysis, Comparison and Evaluation of 

fingerprint evidence, but defines these steps for all types of physical evidence. 

The principles of comparison are discussed in the concepts of uniqueness and 

individualization of physical evidence, with a section devoted to fingerprints. 

Other topics are ethical and moral considerations, class and individual 

characteristics, degrees of opinions, and expert witness testimony.

June 14, 2011 6262
16.What studies exist which compare one toolmark analytical method to another?

Biasotti, A. (1959). A Statistical Study of the Individual Characteristics of Fired Bullets. 

Journal of Forensic Sciences, vol. 4 (1), 34-50.

Validity study in which no more than three consecutively matching striations 

(CMS) were found on lead bullets fired from different guns and no more than four 

CMS were found on jacketed bullets fired from different guns.

Bunch, Stephen G. ―Consecutive Matching Striation Criteria: A General Critique.‖ 

Journal of Forensic Sciences, Vol. 45 (5), Sept. 2000, pp. 955-962. 

This paper critiques the Consecutive Matching Striation (CMS) approach to 

toolmark identification. The author discusses the practical and theoretical 

weaknesses of the approach, argues that it demands a statistical/probabilistic 

treatment of results - such as the use of Bayesian likelihood ratios - and also 

suggests much additional research is needed.

Burrard, G, The Identification of Firearms and Forensic Ballistics, Herbert Jenkins, Ltd., 

London, 1934, Reprinted Barnes & Company 1962 and Wolfe publishing 1990.

This textbook discusses and highlights the reliability of the microscopic 

comparative method.

Chumbly, L. Scott, et al, ―Validation of Tool Mark Comparisons Obtained Using a 

Quantitative, Comparative, Statistical Algorithm‖ Journal of Forensic Sciences, Volume 

55, Number 4, July 2010, pp. 953-961.

A statistical analysis and computational algorithm for comparing pairs of 

toolmarks by profilometry data was conducted. Toolmarks produced by 50 

sequentially made screwdrivers, at selected fixed angles, were analyzed both 

empirically by practicing examiners and by the established computational 

algorithms. The results of these comparisons, as well as a subsequent blind 

study with the practicing examiners, showed scores of good agreement between 

the algorithm and human experts. It was also noted that in some of the 

examination phases, examiner performance was much better than the algorithm.

Gunther, J.D., and Gunther, C.O., The Identification of Firearms, Wiley & Sons, Inc. 

1935.

This textbook discusses and highlights the reliability of the microscopic 

comparative method.

Matthews, J. Howard. Firearms Identification: Volume I, II, and III, University of 

Wisconsin Press 1962.

June 14, 2011 6363
These three textbooks discuss and highlight the reliability of the microscopic 

comparative method.

Goddard, C.H., ―Scientific Identification of Firearms and Bullets‖, Journal of Criminal 

Law and Criminology, Vol. 16, No. 2, August 1926, pp 254-263. 

This article discusses the effectiveness of the microscopic comparative 

method.

Moran, B. (2003). ―Toolmark Criteria for Identification: Pattern Match, CMS, or 

Bayesian?‖ AFTE Journal, Vol. 35, No. 4. pp 359-360. (Reprint from INTERfaces, Vol. 

28, Nov-Dec 2001. pp 9-10.)

Abstract: The purpose of this discussion is to 1.) open a dialogue with both our 

Bayesian and non-Bayesian colleagues in the British Forensic Science Service 

on the topic of approaches to criteria for identification and conclusion giving in 

toolmark (and firearm) identification, 2.) to solicit some specific examples to the 

practical use of Bayes Rule in toolmark identification cases and 3.) to solicit 

feedback on more objective approaches to the interpretation of striated toolmarks 

such as consecutive matching striae (CMS).

Biasotti, A. and Murdock, J. (1984). ―Criteria for Identification or State of the Art of 

Firearms and Toolmark Identification.‖ AFTE Journal, Vol. 16, No. 4. pp 16-24

Authors lay out the current state of firearms identification and what is required to 

determine an identification. They also discuss the practical certainty of an 

identification vs. an absolute identification. The authors lay a foundational 

framework for more objective criteria in the formulation of an identification 

conclusion.

Miller, J. (2001). ―An Examination of the Application of the Conservative Criteria for 

Identification of Striated Toolmarks Using Bullets Fired from Ten Consecutively Rifled 

Barrels.‖ AFTE Journal, Vol. 33, No. 2. pp 125-132.

Abstract: The possibility of the reproduction of subclass characteristics between

fired bullets is most likely to occur from barrels that are consecutively rifled. An 

evaluation of bullets fired from ten consecutively rifled barrels is made using the 

previously proposed conservative criteria for identification of striated toolmarks. 

The influence of any subclass characteristics on an identification and the validity 

of using the conservative criteria for identification as a criteria to determine an 

identification is examined.

Moran, B. (2001). ―The Application of Numerical Criteria for Identification in Casework 

Involving Magazine Marks and Land Impressions.‖ AFTE Journal, Vol. 33, No. 3. pp 41 

– 46.

June 14, 2011 6464
Abstract: This paper addresses the evaluation of magazine marks and the 

magazine surfaces that produce them with regard to potential for subclass and 

individualizing characteristics. It also describes the practical use of numerical 

criteria in the evaluation of striated toolmarks in routine casework (magazine 

marks and rifling impressions) and it‘s significance in providing objective criteria 

for examining striated toolmarks having limited information such as magazine 

marks on fired cartridge cases.

Nichols, R. (2003). ―Consecutive Matching Striations (CMS): Its Definition, Study and 

Application in the Discipline of Firearms and Tool Mark Identification.‖ AFTE Journal, 

Vol. 35, No. 3. pp 298-306.

Abstract: The concept of consecutive matching striations (CMS) has been met 

with aggressive opposition and suspicion within the discipline of firearms and tool

mark identification. It is believed that this is due to a lack of a fuller understanding 

as to its definition and application within the field. The purpose of this paper is to 

help resolve some of the persistent issues that critics of CMS have consistently 

presented throughout the years. To fulfill that purpose, this paper will articulate a 

definition of CMS that helps to demonstrate that it is not in conflict with what has 

been referred to as the traditional pattern matching approach, but is simply a 

means of describing the observed pattern. In addition, the paper will critically 

evaluate and summarize those articles that have had as their basis the intent to 

invalidate the conservative minimum criteria for identification. Finally, this article 

will address frequently expressed concerns in an effort to put them to a final rest.

June 14, 2011 6565
17.What research has been completed, if any, to determine if a threshold exists to 

assess when there is sufficient data to complete an examination?

AFTE Criteria For Identification Committee Report: ―Theory of Identification, Range of 

Striae Comparison Reports and Modified Glossary Definitions-an AFTE Criteria For 

Identification Committee Report‖, AFTE Journal, Vol. 24, No. 3, July 1992, pp. 336-340.

Nichols (see Question 2 for Nichols Part I and Part II references) has 

summarized the scientific studies that allow us, assuming no subclass influence, 

to predict that: 1) the working surfaces of different tools produce discernibly 

different toolmarks even though some quality/quantity of microscopic agreement 

may be present (these toolmarks are referred to as known non-matches) and; 2) 

toolmarks produced by the same tool working surface (referred to as known 

matches) can be identified with one another and exhibit a greater quality/quantity 

of microscopic agreement than known non-matching toolmarks.

The references summarized by Nichols are examples of the extensive testing 

done in this area. As a result of these studies, AFTE formulated and adopted a 

Theory of Identification to explain the basic theory that allows opinions of 

common origin to be made in toolmark comparisons. The AFTE Theory of 

Identification, adopted in 1992, states:

1. The theory of identification as it pertains to the comparison of 

toolmarks enables opinions of common origin to be made when the 

unique surface contours of two toolmarks are in ―sufficient 

agreement‖.

2. This ―sufficient agreement‖ is related to the significant duplication of 

random toolmarks as evidence by a pattern or combination of 

patterns of surface contours. Significance is determined by the 

comparative examination of two or more sets of surface contour 

patterns comprised of individual peaks, ridges and furrows. 

Specifically, the relative height or depth, width, curvature and 

special relationship of the individual peaks, ridges and furrows 

within one set of surface contours are defined and compared to the 

corresponding features in the second set of surface contours. 

Agreement is significant when it exceeds the best agreement 

demonstrated between toolmarks known to have been produced by 

different tools and is consistent with agreement demonstrated by 

toolmarks known to have been produced by the same tool. The 

statement that ―sufficient agreement‖ exists between two toolmarks 

means that the agreement is of a quantity and quality that the 

June 14, 2011 6666
likelihood another tool could have made the marks is so remote as 

to be considered a practical impossibility.

3. Currently the interpretation of individualization/identification is 

subjective in nature, founded on scientific principles and based on 

the examiner‘s training and experience.

In accordance with the AFTE Theory of Identification, and a commitment to 

standardization, AFTE has developed a specific range of conclusions possible 

when comparing toolmarks. As adopted in 1992, the range of conclusions was 

preceded by: ―The examiner is encouraged to report the objective observations 

that support the findings of toolmark examinations. The examiner should be 

conservative when reporting the significance of these observations.‖ These two 

statements were designed to give the examiner license to explain his or her 

reasoning for reaching his or her conclusions. These conclusions are based on a 

specific comparison of individual characteristics, having eliminated any possibility 

of subclass influence. They are:

1. Identification: Agreement of a combination of individual 

characteristics and all discernible class characteristics where the 

extent of agreement exceeds that which can occur in the 

comparison of toolmarks made by different tools and is consistent 

with the agreement demonstrated by toolmarks known to have 

been produced by the same tool.

2. Inconclusive: 

a. Some agreement of individual characteristics and all discernible 

class characteristics, but insufficient for an identification.

b. Agreement of all discernible class characteristics without 

agreement or disagreement of individual characteristics due to 

an absence, insufficiency, or lack of reproducibility.

c. Agreement of all discernable class characteristics and 

disagreement of individual characteristics, but insufficient for an 

elimination.

3. Elimination: Significant disagreement of discernible class 

characteristics and/or individual characteristics.

4. Unsuitable: Unsuitable for examination.

June 14, 2011 6767
It is important to note that the word ―inconclusive‖ does not have to be included in 

a laboratory report. Each of the subcategories under Inconclusive above were

designed to stand alone, as conclusive findings. The word ―inconclusive‖ was 

chosen simply because the three associative evidence statements, a), b), and c) 

are findings less conclusive than Identification.

Biasotti, A. (1959). A Statistical Study of the Individual Characteristics of Fired Bullets. 

Journal of Forensic Sciences, vol. 4 (1), 34-50.

Validity study in which no more than three consecutively matching striations 

(CMS) were found on lead bullets fired from different guns and no more than four 

CMS were found on jacketed bullets fired from different guns. 

Burrard, G. (1934). The Identification of Firearms and Forensic Ballistics. Herbert 

Jenkins, London.

The Gutteridge case is described where 1375 revolvers of the same make/model 

were compared with the suspect revolver. Six of the 1375 had similar irregular 

indentations on the breechfaces. Test firings from these six were distinctly 

different from each other and from the toolmarks on the ―crime‖ cartridge case, 

which matched test firings from the suspect revolver.

Miller J., and McLean M., Criteria for Identification of Toolmarks, AFTE Journal, Vol. 30, 

No. 1, Winter 1998, pp. 15-61.

Miller J., Criteria for Identification of Toolmarks, Part II, AFTE Journal, Vol. 32, No. 2, 

Spring 2000, pp. 116-131.

Miller J. and Neel M., Criteria for Identification of Toolmarks, Part III, AFTE Journal, Vol. 

36, No. 1, Winter 2004, pp. 7-38.

Extensive three-part study on striated toolmarks contained on various caliber

fired bullets was conducted by using a computer to correlate the KM and KNM 

striae groups of these test-fired specimens. These studies validated Biasotti‘s 

previous work that concluded consecutiveness of matching striae is more reliable 

than percent of matching striae. Additionally, these studies support the 

conclusions made by examiners using the conservative quantitative consecutive 

matching striae criteria authored by Biasotti and Murdock in 1997.

Smith, Erich. ―Cartridge Case and Bullet Comparison Validation Study with Firearms 

Submitted in Casework.‖ AFTE Journal, vol. 37 (2), Spring 2005, pp. 130-135.

This validation study was designed to test the accuracy of examinations by 

trained firearms examiners who use pattern recognition as a method for 

identification. Eight FBI examiners took the test that consisted of both bullets 

and cartridge cases. No false positives or false negatives were reported. 

June 14, 2011 6868
Uchiyama T. (1988). A Criterion for Land Mark Identification. AFTE Journal, Vol. 20, No. 

3, 236-251.

This article describes the examination process of firearms identification beginning 

with class characteristic agreement and followed by individual characteristic 

agreement. The use of a digital image processor is discussed as a viable

counting method of lines on a bullet.

Uchiyama T. (1988). A Criterion for Land Mark Identification Using Rare Marks. AFTE 

Journal, Vol. 20, No. 3, 260-268.

In this paper, an example is presented for making a judgment of identity based 

on rare marks appearing on metal jacketed bullets. The significance level of the 

calculated probability estimates using this model is only moderately low.

June 14, 2011 6969
18.What research has been completed, if any, to determine the threshold for 

identification (individualization)? 

STRIATED TOOLMARKS:

Quantitative Consecutive Matching Striae (CMS) Theory

There are a number of scientists in the firearm/toolmark identification community who 

have specifically researched the individuality of striated toolmarks based on the quantity 

of consecutively matching striae. These scientists approached this through the use of 

theoretical, mathematical, and empirical studies. By doing this, the examiner is able, 

from data gathered using the scientific method, to assign measurable weight to the 

qualitative component described in the AFTE Theory of Identification. This allows the 

examiner to supplement his/her training and experience with data that is scientifically 

defensible. The following references validate this approach:

GENERAL

1959 – Biasotti, A., A Statistical Study of the Individual Characteristics of Fired Bullets. 

Journal of Forensic Sciences. 1959 Jan; 4(1): 34-50.

This paper summarizes the study of the probability of occurrence of consecutive 

matching striae in land impressions from fired bullets in both match and 

nonmatch positions reported by the author in 1955. The findings are based on 

the author‘s research conducted between 1951 and 1955. Biasotti concluded 

that, ―The most significant point of the data collected is the fact that 3 

consecutive matching lines for lead bullets and 4 consecutive matching lines for 

metal-cased bullets appears to be the dividing line between data for same and 

different guns; and therefore, these critical series form the base line upon which 

the data for bullets from the same gun can be differentiated from the data for 

different guns.‖ Therefore, approximately 3 - 4 consecutive matching striae 

appeared to be the threshold number between a known match and known nonmatch.

MATHEMATICAL MODELS

1970 – Brackett, J., A Study of Idealized Striated Marks and Their Comparison Using 

Models. Journal of the Forensic Science Society. 1970; 10(1): 27-56.

Brackett published his study of various mathematical models that could be 

applied to the study of ―idealized‖ striated marks including geometric models, 

number-based models, random number outcome models, and random number 

replica models. His purpose was to develop a theoretical basis for striated mark 

analysis that could be developed into mechanical (empirical) models that could 

June 14, 2011 7070
be compared to toolmarks in order to obtain sufficient information to establish 

objective criteria for identity between two sets of toolmarks. He discovered from 

these different models that the development of a random number table was quite 

reliable in representing a striated toolmark model. Although his ideal striations 

were devoid of width, his work is significant in that he demonstrated the concept 

of consecutiveness alone to be a very powerful tool in deciphering coincidence 

from common associations. His ideal mathematical striated marks model was 

described as ―tedious‖, but it closely supported the empirical study of consecutive 

matching striae conducted by and reported in 1959 by Biasotti. The author 

suggested that such models could be more practically used with the assistance 

of computers in the future.

1980 – Blackwell, R., Framan, E. Automated Firearms Identification System (AFIDS): 

Phase I. AFTE Journal 1980 Oct; 12(4): 11-37.

Blackwell and Framan published their research into the development of 

automated firearms identification systems. In their concern for establishing 

applicable criteria for developing computerized systems that could be objectively 

and reliably ―utilized to help establish a more factual basis for determining identity 

and nonidentity between two pairs of fired bullets‖, the authors researched the 

literature. The results of this effort revealed that there was little in the literature 

that provided such objective criteria that could provide a ―universal factual basis 

for establishing identity of a firearm‖ with the exception of the work of Biasotti 

reported in 1959. They observed ―Biasotti has conducted research which could 

prove very useful to future developments in firearm identification‖. To investigate 

this possibility, the authors conducted a simulation study of striated marks by 

applying Brackett‘s formulas and models, which they found reliable, and in 

agreement with each other. Results of their work were found to be in general 

agreement with the results of Biasotti‘s empirical studies described in 1959. They 

observed in the simulation study that ―the results substantiated Biasotti‘s 

hypothesis and regardless of the phase relationship of one sequence with the 

other, the chance occurrence of consecutive matching lines exceeding those 

proposed by Biasotti did not occur.‖

1981 – Deinet, W., Studies of Models of Striated Marks Generated by Random 

Processes. Journal of Forensic Sciences 1981 Jan; 26(1): 35-50.

Dienet described his use of computer-aided studies of the degree of similarity of 

striated markings. Dienet addressed the problem that ―a high degree of similarity 

between two sets of marks is not sufficient to identify a tool if it is highly probable 

that the similarity may occur by chance‖. With this in mind, Dienet defined this 

problem in the form of the following question: ―Given two patterns that are similar 

June 14, 2011 7171
to a certain degree, what is the probability that such a similarity, or an even 

greater one, occurs at random?‖ He attempted to answer this question by 

constructing models based on assumptions that: ―1) random processes generate 

the patterns on the tools; 2) different patterns on tools produced by the same 

machine are independent; and 3) the probability of the occurrence of a line is 

independent of its position‖. His paper described the calculation of probability of 

random occurrence of matches using actual striated toolmarks using blades of 20 

shears that were ground to produce random imperfections that were then used to 

produce toolmarks in lead. Two sets of marks were produced with each tool and 

a 1.2 mm portion of each pattern was photographed and scanned into the 

computer. The images were prepared and evaluated with respect to line position. 

The ―Digitized image data on 40 grinding marks were fed into a minicomputer, 

and the position values of the lines were determined semi-automatically.‖ 

Idealized models were defined for an objective comparison of striated marks and 

then applied to the grinding mark data. Necessary conditions of the models were 

tested by comparing them with actual measured properties of the marks. Three 

different probability theory models were examined including combinatorial model, 

a renewal theory model, and binomial function fit model. The results of the model 

calculations were presented and the properties of the models were discussed. 

Each model presented certain strengths and weaknesses in fulfilling the above 

three requirements but were not entirely ideal. However, he also concluded that 

―numerical values computed with the aid of models permit an evaluation of the 

degree of similarity‖ and ―for automation of pattern comparisons a preselection is 

possible, but any probability-related statements require additional studies and 

examinations‖

1988 – Uchiyama, T., A Criterion for Land Mark Identification. AFTE Journal 1988 Jul; 

20(3): 236-251.

Uchiyama sought to develop criteria for identification of land impressions using 

probability theory and also developed a significance level associated with this 

approach. This was developed because of his observations that neither the total 

number of matching striae nor the percentage of matching striae was sufficient to 

establish identity. His significance level approach provided an evaluation of 

goodness of fit and primarily provided the probability of an accidental or random 

match of striae. He developed the probability equation based on actual fired 

bullets. Using his significance level of evaluation he observed that 

consecutiveness of matching striae played a principle part in indicating the 

identity of bullets fired from the same gun.

1992 – Uchiyama, T., The Probability of Corresponding Striae in Toolmarks. AFTE 

Journal 1992 Jul; 24(3): 273-290.

June 14, 2011 7272
Uchiyama‘s study provides an estimate of the maximum number of consecutively 

corresponding lines that might be expected given the considerations of: 1) striae 

density; 2) critical coincidence ratio (CCR – a method of quantitatively 

representing how well two lines match relative to width, a range of zero to 1 with 

1 being a perfect match); and 3) striae width. He developed a computer model to 

generate and compare striated toolmarks using these considerations. His model 

demonstrated that when the widths of lines were varied (as might be expected in 

actual striated toolmarks), the number of coincidental consecutive matching 

striae decreased with increasing deviations in striae width. From this 

experimentation he demonstrated that the additional influence of line width, in the 

critical evaluation of consecutive agreement, had significant additional influence 

on the maximum number of matching consecutive striae. When the conditions of 

his variables were such that the coefficient of variation for striae width was 0.9 

and the CCR value was 0.8, the maximum number of coincidental consecutive 

matching striae was approximately 3 – 4. These results of a maximum of 3 to 4 

consecutive lines that would represent a known nonmatch very closely agreed 

with Biasotti's original empirical work.

1997 – Biasotti, A., Murdock, J., in Faigman DL, Kaye DK, Saks MJ, Sanders J, editors. 

Modern Scientific Evidence: The Law and Science of Expert Testimony. St. Paul: West, 

1997 – Chapter 23, Firearms and Toolmark Identification

This work includes, for the first time, a proposed conservative numerical criterion 

based on counting runs of consecutive matching striae. The purpose of this 

proposal was to offer a standard that could be used to distinguish between a 

striated toolmark identification and non-identification. The developed 

conservative quantitative criteria is as follows:

 In three dimensional toolmarks when at least two different groups of at 

least three consecutive matching striae appear in the same relative 

position, or one group of six consecutive matching striae are in agreement 

in an evidence toolmark compared to a test toolmark.

 In two dimensional toolmarks when at least two groups of at least five 

consecutive matching striae appear in the same relative position, or one 

group of eight consecutive matching striae are in agreement in an 

evidence toolmark.

 For these criteria to apply, however, the possibility of subclass 

characteristics must be ruled out.

Since this chapter was first published in 1997, there have been a number of 

studies which have included an evaluation, using quantitative consecutive 

matching striae, of the numerical criteria for the identification of striated toolmarks 

proposed above by Biasotti and Murdock. No known non-matching (two or three 

June 14, 2011 7373
dimensional) toolmarks were found in these studies which exhibited agreement in 

excess of the proposed Biasotti-Murdock criteria. These studies, as well as a 

description of a survey and training in the use of quantitative CMS as a criterion 

for the identification of striated toolmarks are described on pages 702 through 

707 of the following reference:

Biasotti, A., Murdock, J., Moran, B., Firearms and Toolmark Identification. 

Chapter 35, Vol.4, pp 645-723 in Modern Scientific Evidence: The Law 

and Science of Expert Testimony (Faigman DL, Kay DK, Saks MJ, 

Sanders, J, Chen EK., eds, 2009-2010), St. Paul: Thompson-West.

A footnote on pages 681 through 685 in the above reference discusses the 

consideration of subclass toolmark influence. Toolmarks of any kind cannot be 

identified if subclass influence is present.

IMPRESSED TOOLMARKS:

Biasotti, A., Murdock, J., Moran, B., Firearms and Toolmark Identification. Chapter 35, 

Vol.4, pp 645-723 in Modern Scientific Evidence: The Law and Science of Expert 

Testimony (Faigman DL, Kay DK, Saks MJ, Sanders, J, Chen EK., eds, 2009-2010), St. 

Paul: Thompson-West.

Research conducted thus far by Biasotti, Murdock, and Moran, indicates that the 

practical probabilities limits in known non-matches for impression toolmarks 

similar to those found for striated toolmarks. Some progress has been made in 

developing quantitative criteria for the identification of compression toolmarks. 

Following Stone‘s publication of a theoretical model for the mathematical 

evaluation of well defined types of impressed toolmarks, Collins used and 

evaluated Stone‘s model while performing an empirical study of twenty worn 

hammer faces. His preliminary results show that combinations of even low 

numbers of simple impressed defects are, on a practical level, quite 

discriminating. However, more research is needed involving very fine, high 

density, randomly distributed individual impression characteristics, viewed two 

dimensionally, before definitive practical probability limits can be stated 

confidently.

Stone, R. ―How Unique are Impressed Toolmarks?‖ AFTE Journal. Vol. 35, No. 4, Fall 

2003. pp. 376-383.

The comparison model developed by Stone offers a springboard upon which 

those interested in studying the occurrence of impressed contours and 

establishing the basis for a quantifiable identification criterion of impressed 

toolmarks may now do so.

June 14, 2011 7474
Collins, E. ―How Unique are Impressed Toolmarks: An Empirical Study of 20 Worn 

Hammer Faces.‖ AFTE Journal. Vol. 37, No. 4, Fall 2005. pp. 252-295.

Collins tested the validity of Stone‘s theories on the statistical uniqueness of 

impressed toolmarks through the empirical examination of the defects observed on 

the faces of twenty hammers that had been subjected to various degrees of wear 

and abuse through normal use. These examinations were carried out under 

controlled conditions that would simulate those used in practical casework. The 

results of this study led to a re-evaluation of Stone‘s work and a modification of 

related formulae. The revised formulae were used to calculate practical but 

conservative probabilities associated with impressed toolmarks using the data 

collected from the hammers in the study.

June 14, 2011 7575
19.Does research exist which demonstrates that criteria for identifications 

(individualization) vary with method of manufacture or type of tool?

The AFTE Theory of Identification, adopted by AFTE in 1992, is intended to be 

universal, accounting for all known methods of manufacture.

Biasotti, A.A., ―Statistical Analysis of Bullet Comparison (Preliminary, Unpublished, 

Report for Masters Thesis)‖, prepared for Criminology 299 course, University of 

California Berkeley, June 1, 1951.

In this report, Biasotti described how the purpose of his research was to arrive at a 

concept of probability for bullet comparison based on the relative frequency of 

occurrence of common characteristics (e.g. consecutive series of matching lines) 

between bullets fired from the same gun and bullets fired from similar guns of the 

same caliber. He went on to describe how 1) the purpose of his study was to give 

the Criminalist some basis for establishing what constitutes a match and what 

degree of probability can be attached and 2) the relative frequency of occurrence of 

consecutive series as will be compiled in this study could be used directly as 

empirical findings without deriving any concept of probability; but if this were done, 

the data would apply only to the particular type of gun and ammunition used in this 

particular study. Then similar studies would have to be conducted for every gun of 

different manufacture of the same caliber and for every different type of ammunition 

to be significant. Biasotti completed his Masters thesis, ―Bullet Comparison – A 

Study of Fired Bullets, Statistically Analyszed, ― in February 1955 and published his 

findings in the Journal of Forensic Sciences, Vol 4., No. 1, Jan. 1 1959, pp. 34-50.

In 1997, forty six years after stating in his 1951 student progress report, Biasotti (in 

collaboration with John Murdock) decided that sufficient research had been done on 

both firearms and non-firearms toolmakrs to justify publishing the conservative 

quantitative criteria for striated toolmarks. (Listed under Question 18). The criteria 

was published in reference (A) below and remains the same in the current edition of 

Modern Scientific Evidence (reference (B) below).

(A) Biasotti, A., Murdock, J., Chapter 23, ―Firearms and Toolmark Identification‖ from 

Modern Scientific Evidence: The Law and Science of Expert Testimony, Vol. 2, West 

Pub. Co., 1997, pp. 124-155; and (B) Biasotti, A., Murdock, J., Moran, B., Firearms 

and Toolmark Identification. Chapter 35, Vol.4, pp 645-723 in Modern Scientific 

Evidence: The Law and Science of Expert Testimony (Faigman DL, Kay DK, Saks 

MJ, Sanders, J, Chen EK., eds, 2009-2010), St. Paul: Thompson-West.

June 14, 2011 7676
20.What studies have been performed to determine error rates in firearm and 

toolmark analyses? What studies have been performed to determine examiner 

error rates? What research exists which identifies rates for misidentifications 

and false exclusions?

See responses to Question #21.

June 14, 2011 7777
21.Do studies exist which demonstrate how often false negatives (e.g. a nonmatch is declared, when they match) are reported?

Error rates in actual casework are difficult to assess due to a lack of ―ground truth.‖ 

Proficiency tests are not administered in a consistent, controlled manner but do provide 

a large amount of data. Validity tests employ various levels of blindness and control, 

but are usually designed to create a ―worst case scenario‖ in which consecutively 

machined firearms and tools are used. 

Proficiency Tests

Crime Laboratory Proficiency Testing Results, 1978*1991, II: Resolving Questions of 

Common Origin, Journal of Forensic Sciences, Vol. 40, No. 6, Nov. 1995, pp.1009-29.

Article examined the origins of crime laboratory proficiency testing and the 

performance of laboratories in the identification and classification of common 

types of physical evidence. Part II reviews laboratory proficiency in determining if

two or more evidence samples shared a common source. Parts I and II together 

review the results of 175 separate tests issued to crime laboratories over the 

period 1978 to 1991.

CTS 1978 - 1991, Stephen Bunch summary and slight revision of Peterson & Markham 

F/T results. 

Internet Source: www.swggun.org/resources/admissibility/prof_test results081603.pdf

Proficiency Test Results from Peterson and Markham Article - Firearms

Source: ―Crime Laboratory Proficiency Test Results, 1978-1991, II: Resolving Questions 

of Common Origin,‖ Journal of Forensic Sciences, Vol. 40, No. 6, November 1995, pp. 

1009 -1029. (12 separate tests involving between 42 and 173 laboratories.)

From Table 8, page 1019:

Total comparisons = 2106

False identifications = 12

False eliminations = 17

True identification conclusions = 905

True elimination conclusions = 954

True identifications judged inconclusive = 43

True eliminations judged inconclusive = 175

Total true identifications = 905 + 43 + 17 = 965

Total true eliminations = 954 + 175 + 12 = 1141

Total identification conclusions offered = 905 + 12 = 917

Total elimination conclusions offered = 954 + 17 = 971

Total inconclusives = 43 + 175 = 218

Data Analysis – Firearms

Test Sensitivity = true IDs offered/true IDs = 905/965 = 93.78%

Test Specificity = true eliminations offered/true eliminations = 954/1141 = 83.61%

June 14, 2011 7878
False positive error rate (false or mis-identifications) = false positive 

responses/total true eliminations = 12/1141 = 1.05%

False negative error rate (false or mis-eliminations) = false negative 

responses/total true identifications = 17/965 = 1.76%

Inconclusive rate = 218/2106 = 10.35%

Proficiency Test Results from Peterson and Markham article - Toolmarks

Source: ―Crime Laboratory Proficiency Test Results, 1978-1991, II: Resolving Questions 

of Common Origin,‖ Journal of Forensic Sciences, Vol. 40, No. 6, November 1995, pp. 

1009 - 1029. (12 separate tests involving between 72 and 163 laboratories.)

From Table 13, page 1024:

Total comparisons = 1961

False identifications = 30

False eliminations = 44

True identification conclusions = 646

True elimination conclusions = 755 + 53 + 44 = 852

True identifications judged inconclusive = 83 + 48 = 131

True eliminations judged inconclusive = 258

Total true identifications = 646 + 44 + 48 = 821

Total true eliminations = 852 + 30 + 258 = 1140

Total identification conclusions offered = 646 + 30 = 676

Total elimination conclusions offered = 852 + 44 = 896

Total inconclusives = 83 +258 + 48 = 389

Under toolmarks, the authors include a category of ―unjustified exclusions.‖ An example: 

two wires cut by different areas on the cutting edge of a single pair of wire cutters was 

marked by a participant as an elimination. While this mistake would be understandable 

if one merely considers microscopic correspondence and ignores the larger picture, it 

was properly categorized as an unjustified exclusion, and counted here as a false 

negative. In other cases, however, the responses were correct from a scientific 

perspective (only false positives and false negatives matter), but incorrect from a 

training and quality assurance perspective. For my purposes, the scientific propositions 

trump quality assurance considerations, and thus the remaining ―unjustified exclusions‖ 

were counted as correct responses.

CTS 1992 – 2005, F/T results revisions by Douglas Murphy, Presentation at 2010 AFTE 

Training Seminar (also at www.swggun.org/resources/docs/CTSErrorRates.pdf)

CTS Error Rates: 1992 – 2005

Firearms False Positive = 1.5%

Firearms False Negative = 0.5%

Toolmark False Positive = 1.7%

Toolmark False Negative = 1.6%

The two preceding summaries were produced by applying standard error rate 

calculation methods to results reported by CTS, to include false positive and 

false negative rates, sensitivity and specificity.

June 14, 2011 7979
Validity Tests

Teale, Popular Science Monthly, February 1932, p.213

The author reports on studies by Calvin Goddard of markings produced by six 

consecutively manufactured firing pins and four consecutively manufactured gun 

barrels. These studies appear to be the first documented attempt to test the 

firearm examiner‘s ability to distinguish between consecutively manufactured 

tools. This is the traditional ―worst case scenario‖ testing that has been 

conducted by firearm and toolmark examiners to validate the ability to 

individualize tools. With regard to the firing pin study, Teale relates the following: 

―To prove his case, Col. Goddard told me he sent to the factory where for the 

suspect‘s gun was manufactured and obtained half a dozen firing pins made on 

the same machine one after another‖ and ―the differences are apparent in the 

confirmation of the tips of six firing pins made successively on the same 

machine. Contact with the cartridge caps will leave identifying imprints.‖ With 

regard to the study of markings produced on consecutively manufactured gun 

barrels, Teale notes that ―Not long ago at the Springfield Armory, in 

Massachusetts, bullets were fired through four rifles that had been made one 

after the other on the same machine. The Markings on the bullets were so 

different that each bullet could be traced to the gun that fired it.‖

A short description of each of the following articles, see the SWGGUN ARK, Error Rates 

and Power Point slide #62 in SWGGUN ARK- Appendix I. 

Internet Source: 

www.swggun.org/swg/index.php?option=com_content&view=article&id=6:error-rateresources&catid=9:ark&Itemid=18

Brundage, David J. ―The Identification of Consecutively Rifled Gun Barrels.‖ AFTE 

Journal, Vol. 30, No. 3, Summer, 1998, pp. 438-444.

DeFrance, Charles S. and Michael VanArsdale. ―Validation Study of Electrochemical 

Rifling.‖ AFTE Journal, Vol. 35, No. 1, Winter, 2003, pp. 35-37.

Fadul, T.G., ―An Empirical Study to Evaluate the Repeatability and Uniqueness of 

Striations/Impressions Imparted on Consecutively Manufactured Glock EBIS Gun 

Barrels‖, AFTE Journal, Volume 43, Number 1, Winter 2011, Pp. 37-44.

Hamby J. E., Brundage D. J. , Thorpe J. W., ―The Identification of Bullets Fired from 10 

Consecutively Rifled 9mm Ruger Pistol Barrels: A Research Project Involving 507 

Participants from 20 Countries‖, AFTE Journal, Volume 41, Number 2, Spring 2009, pp. 

99-110.

Smith E., ―Cartridge Case and Bullet Comparison Validation Study with Firearms 

Submitted in Casework.‖ AFTE Journal, vol. 37 (2), Spring 2005, pp.130-135.

June 14, 2011 8080
Bunch, S.G. and Murphy D.P.. ―A Comprehensive Validity Study for the Forensic 

Examination of Cartridge Cases.‖ AFTE Journal, Vol. 35, No. 2, Spring 2003, pp. 201-

203.

Giroux B. N., ―Empirical and Validity Study: Consecutively Manufactured Screwdrivers‖, 

AFTE Journal, Volume 41, Number 2, Spring, 2009, Pp. 153-158.

Lyons, D. J., ―The Identification of Consecutively Manufactured Extractors‖, AFTE 

Journal, Volume 41, Number 3, Summer, 2009, Pp.246-256.

Thompson, Evan and R. Wyant, ―Knife Identification Project (KIP),‖ AFTE Journal, Vol. 

35 (4), Fall 2003, Pp. 366 – 370.

Christensen AM, Sylvester AD., Physical Matches of Bone, Shell and Tooth Fragments: 

A Validation Study. Journal of Forensic Sciences, 2008;53, Pp.694-698

Orench, Jose A., ―A Validation Study of Fracture Matching Metal Specimens Failed in 

Tension,‖ AFTE Journal, vol. 37 (2), Spring 2005, pp. 142-149.

Grzybowski, R., Miller, J., Moran, B., Murdock, J., Nichols, R., and R. Thompson. 

―Firearm/Toolmark Identification: Passing the Reliability Test Under Federal and State 

Evidentiary Standards.‖ AFTE Journal, vol. 35 (2), Spring 2003, pp. 209-241.

There is a particularly good discussion, with references listed below, of error rate on 

page 216 through 230 of this article. This description includes reported summaries of 

firearm and non-firearm proficiency tests, what is done in most forensic laboratories 

to ensure that the results of individual cases are correct as reported, and the error 

rate of individual examiners.

References for above article:

Biasotti, A., Murdock, J., Moran, B., Firearms and Toolmark Identification. 

Chapter 35, Vol.4, pp 645-723 in Modern Scientific Evidence: The Law and 

Science of Expert Testimony (Faigman DL, Kay DK, Saks MJ, Sanders, J, Chen 

EK., eds, 2009-2010), St. Paul: Thompson-West.

Moenssens, A., ―Meeting the Daubert Challenge to Handwriting Evidence –

Preparing for a Daubert Hearing‖, abstract of a talk given at the Second Annual 

Symposium on the Forensic Examination of Questioned Documents at Albany, 

N.Y. on June 18, 1999. (see www.forensic-evidence.com) An earlier version of 

this also appears in the October, 1999 issue of the Forensic Science 

Communications, a peer reviewed quarterly journal published on the Internet by 

FBI Laboratory personnel (see 

http://www.fbi.gov/programs/lab/fsc/current/index.htm)

June 14, 2011 8181
Peterson, J., and Markham, P., ―Crime laboratory testing results, 1978 – 1991, II: 

Resolving Questions of Common Origin.‖ Journal of Forensic Science, 1995: 

40(6): 1009-1029.

June 14, 2011 8282
22.Are there studies in toolmarks that identify what information/circumstances 

may bias an examiner's conclusion?

Refer to answer under Question 23.

June 14, 2011 8383
23.Are there specific studies showing a difference in rate of inconclusive versus 

conclusive as a result of “contextual bias” information?

The following articles largely deal with fingerprints. But, to answer questions 22 & 23, 

this is the best information we have due to the close similarity to how fingerprint 

examiners and firearm examiners perform their tasks. These articles deal with 

fingerprints, but the types of influences present to a fingerprint examiner can generally 

be characterized as the same for a firearm examiner; however, please do not assume 

that if firearm and toolmark examiners were faced with the same induced biases that 

similar mistakes would occur. No such studies have been conducted for firearms and 

toolmark evidence, but they probably should be conducted.

Budowle, B., et al. (2009). ―A Perspective on Errors, Bias, and Interpretation in the 

Forensic Sciences, and Direction for Continuing Advancement.‖ Journal of Forensic 

Sciences, Vol. 54, No. 4. Pp 798-809.

Abstract: The forensic sciences are under review more so than ever before. 

Such review is necessary and healthy and should be a continuous process. It 

identifies areas for improvement in quality practices and services. The issues 

surrounding error, i.e., measurement error, human error, contextual bias, and 

confirmatory bias, and interpretation are discussed. Infrastructure is already in 

place to support reliability. However, more definition and clarity of terms and 

interpretation would facilitate communication and understanding. Material 

improvement across the disciplines should be sought through national programs 

in education and training, focused on science, the scientific method, statistics, 

and ethics. To provide direction for advancing the forensic sciences a list of 

recommendations ranging from further documentation to new research and 

validation to education and to accreditation is provided for consideration. The list 

is a starting point for discussion that could foster further thought and input in 

developing an overarching strategic plan for enhancing the forensic sciences.

Koehler, J. ―Fingerprint Error Rates and Proficiency Tests:What They Are and Why

They Matter.‖ Citation: 59 Hastings L.J. 1077 2007-2008.

Introduction text of article: When a fingerprint examiner declares a match 

between a print from a known source and a latent print recovered from a crime 

scene,' his word may seal a defendant's fate like no other form of evidence save, 

perhaps, DNA. At trial the fingerprint examiner will offer little in the way of data, 

statistical tests, or uncertainty. Instead, he will say that latent print could only 

have been made by the source of the known print, that he is 100% certain, that 

he has never erred, and that the method he used to make this and other 

identifications has an error rate of zero.' In recent years, the broader scientific 

community has objected to this form of testimony. Critics charge that fingerprint 

analysis lacks an empirical foundation and that examiners make exaggerated

claims that are likely to mislead jurors.

June 14, 2011 8484
Dror, I., Charlton, D., and Peron, A., ―Contextual Information Renders Experts 

Vulnerable to Making Erroneous Identification‖, Forensic Science International 2006, 

156: 74-78. 

Abstract: We investigated whether experts can objectively focus on feature 

information in fingerprints without being misled by extraneous information, such 

as context. We took fingerprints that have previously been examined and 

assessed by latent print experts to make positive identification of suspects. Then 

we presented these same fingerprints again, to the same experts, but gave a 

context that suggested that they were a no-match, and hence the suspects could 

not be identified.Within this new context, most of the fingerprint experts made 

different judgements, thus contradicting their own previous identification 

decisions. Cognitive aspects involved in biometric identification can explain why 

experts are vulnerable to make erroneous identifications.

Dror, I., Charlton, D., Hind, S. and Peron, A., ―When Emotions Get the Better of Us: The 

Effect of Contextual Top-Down Processing on Matching Fingerprints‖, Applied Cognitive 

Psychology 2005, 19: 799-809.

Abstract: Twenty-seven participants made a total of 2,484 judgments whether a 

pair of fingerprints matched or not. A quarter of the trials acted as a control 

condition. The rest of the trials included top-down influences aimed at biasing the 

participants to find a match. These manipulations included emotional background 

stories of crimes and explicitly disturbing photographs from crime scenes, as well 

as subliminal messages. The data revealed that participants were affected by the 

top-down manipulations and as a result were more likely to make match 

judgments. However, the increased likelihood of making match judgments was 

limited to ambiguous fingerprints. The top-down manipulations were not able to 

contradict clear non-matching fingerprints. Hence, such contextual information 

actively biases the ways gaps are filled, but was not sufficient to override clear 

bottom-up information.

Dror, I. and Rosenthal, R., ―Meta-analytically Quantifying the Reliability and Biasability 

of Forensic Experts‖, Journal of Forensic Science July 2008, 53(4): 900-903. 

Abstract: In this paper we employ meta-analytic procedures and estimate effect 

sizes indexing the degree of reliability and biasability of forensic experts. The 

data are based on within-expert comparisons, whereby the same expert 

unknowingly makes judgments on the same data at different times. This allows 

us to take robust measurements and conduct analyses that compare variances 

within the same experts, and thus to carefully quantify the degree of consistency 

and objectivity that underlie expert performance and decision making. To achieve 

consistency, experts must be reliable, at least in the very basic sense that an 

expert makes the same decision when the same data are presented in the same 

circumstances, and thus be consistent with themselves. To achieve objectivity, 

experts must focus only on the data and ignore irrelevant information, and thus 

be unbiasable by extraneous context. The analyses show that experts are not 

June 14, 2011 8585
totally reliable nor are they unbiasable. These findings are based on the 

fingerprint expert‘s decision making, but because this domain is so well 

established, they apply equally well (if not more) to all other less established 

forensic domains.

Dror, I. and Charlton, D. ―Why Experts Make Errors‖, Journal of Forensic Identification 

2006, 56(4): 600-616.

Abstract: Expert latent fingerprint examiners were presented with fingerprints 

taken from real criminal cases. Half of the prints had been previously judged as 

individualizations and the other half as exclusions. We re-presented the same 

prints to the same experts who had judged them previously, but provided biasing 

contextual information in both the individualizations and exclusions. A control set 

of individualizations and exclusions was also re-presented as part of the study. 

The control set had no biasing contextual information associated with it. Each 

expert examined a total of eight past decisions. Two-thirds of the experts made 

inconsistent decisions. The findings are discussed in terms of psychological and 

cognitive vulnerabilities.

Dutton, G. (1998) ―The Importance of Being Impartial.‖ AFTE Journal 30(3): 523-526.

Text from Article: Most firearm examiners around the globe are paid their wage 

by their respective governments, whether this is at a local, state, or federal 

authority. Although this means examiners work for the prosecution "side" in the 

investigation of crime, it does not mean that the evidence examiners give should 

be weighted towards the prosecution case. The testimony as expert witnesses 

must be absolutely impartial. The firearms examiner that is not impartial is doing 

the field a great disservice and subject to possible ramifications from the AFTE 

code of ethics.

Gianelli, P. (2007). ―Confirmation Bias.‖ Criminal Justice, Vol. 22. pp 60-61.

The author discusses the concepts of motivational and cognitive bias and how it 

relates to forensic examinations.

Hodge, E. (1988). ―Guarding Against Error.‖ AFTE Journal, Vol. 20, No. 3. pp 290-293.

The author discusses potential errors and omissions in casework. He further 

discusses five ways to reduce error: training, case organization, the removal of

psychological pressures, checking your work, and using the partner system. 

Koppl, R. and Whitman, G. (2010). ―Rational Bias in Forensic Science.‖ Law, Probability 

& Risk, Vol. 9. pp 69-90.

Abstract: The current organization of forensic science induces biases in the 

conduct of forensic science even if forensic scientists are perfectly rational. 

Assuming forensic examiners are flawless Bayesian statisticians helps us to 

June 14, 2011 8686
identify structural sources of error that we might otherwise have undervalued or 

missed altogether. Specifically, forensic examiners‘ conclusions are affected not 

just by objective test results but also by two subjective factors: their prior beliefs 

about a suspect‘s likely guilt or innocence and the relative importance they attach 

to convicting the guilty rather than the innocent. The authorities—police and 

prosecutors—implicitly convey information to forensic examiners by their very 

decision to submit samples for testing. This information induces the examiners to 

update their prior beliefs in a manner that results in a greater tendency to provide 

testimony that incriminates the defendant. Forensic results are in a sense 

 ̳contaminated‘ by the prosecution and thus do not provide jurors with an 

independent source of information. Structural reforms to address such problems 

of rational bias include independence from law enforcement, blind proficiency 

testing and separation of test from interpretation.

Paust, J. (1978). ―Dum-Dum Bullets, Law, and  ̳Objective‘ Scientific Research: The 

Need for a Configurative Approach to Decision‖, Jurimetrics, Vol. 18. pp 68-278. 

Text from Article: An examination of an article in Science magazine by Kenneth 

Hammond and Leonard Adelman on "Science, Values, and Human Judgment"

seems to demonstrate, contrary to the views of its authors, that science, values 

and bias are necessarily integrated. In an attempt to "objectify" some recent 

research on the societal characteristics of hollow-point (or "dum-dum") handgun 

bullets, Messrs. Hammond and Adelman have defined and applied a seriously 

flawed, one-sided approach to decisions about weapons effects. They have 

allowed hidden choice points (about values, bias, what should be measured and 

how it should be measured) to impair their attempts at scientific research, 

objective inquiry and unprejudiced conclusions. In short, the values and biases of 

the scientists have been built into the definitional framework for their scientific 

inquiry and, thus, into the quantified results.

Risinger, D., Saks, M., Thompson, W., and Rosenthal, R. (2002). ―The Daubert/Kuhmo 

Implications of Observer Effects in Forensic Science: Hidden Problems of Expectation 

and Suggestion‖, California Law Review January 2002, 90(1):1-56.

The authors discuss the concept of observer effects in general as well as in 

forensic science as a whole. They also discuss ways in which to reduce 

observer effects.

June 14, 2011 8787
24.Does research exist which uses class characteristics to describe the relative 

rarity of source firearms based on the population of firearms that can be 

estimated?

No. Although the FBI has a General Rifling Characteristics (GRC) database, it is 

intended as an investigative tool and does not include population information.

June 14, 2011 8888
25.What statistical research has been conducted and applied to firearm and 

toolmark examinations? What statistical models for firearms and toolmarks 

have been published? 

The following 14 articles have been abstracted elsewhere in this document in the 

response to other questions:

Neel, Michael (et al.), A Comprehensive Statistical Analysis of Striated Tool Mark 

Examinations Part 1: Comparing Known Matches and Known Non-Matches, AFTE 

Journal, Volume 39, No. 3, Summer, 2007, pp 174-196

Faden, D. (et al.), Statistical Confirmation of Empirical Observations, AFTE Journal, 

Volume 39, Number 3, Summer 2007, 211-220

Bachrach, Ben. ―Development of a 3D-Based Automated Firearms Evidence 

Comparison System.‖ Journal of Forensic Sciences, Vol. 47, No. 6, November, 2002, 

pp. 1253-1264.

Biasotti, Alfred A. ―A Statistical Study of the Individual Characteristics of Fired Bullets.‖ 

Journal of Forensic Sciences, Vol. 4, No. 1, January, 1959, pp. 34-50.

Intelligent Automation, Incorporated, ―A Statistical Validation of the Individuality 

of Guns Using High Resolution Topographical Images of Bullets ‖, National 

Institute of Justice Grant #2006-DN-BX-K030, October, 2010

Howitt D., Tulleners F., ―A Calculation of the Theoretical Significance of Matched 

Bullets,‖ Journal of Forensic Sciences, Volume 53, Number 4, July 2008, pp. 868-875.

Neel M., and Wells M., ―A Comprehensive Statistical Analysis of Striated Tool Mark 

Examinations Part I: Comparing Known Matches and Known Non-Matches‖, AFTE 

Journal, Volume 39, No. 4, Summer 2007, pp. 176-198.

May L., ―Identification of Knives, Tools and Instruments‖, Journal of Police Science , 

Volume 1, No. 3, 1930, pp. 247-248.

Deinet, Werner. ―Studies of Models of Striated Marks Generated by Random 

Processes.‖ Journal of Forensic Sciences, Vol. 26 (1), Jan., 1981, pp. 35-50.

Stone, Rocky, ―How Unique are Impressed Marks,‖ AFTE Journal, Vol. 35, No.4, Fall 

2003, pp. 376-383.

Collins, Eric R., ―How ―Unique‖ Are Impressed Toolmarks? – An Empirical Study of 20 

Worn Hammer Faces,‖ AFTE Journal, Vol. 37 (4), Fall 2005, pp. 252-295.

June 14, 2011 8989
Chumbly, L. Scott, et al, ―Validation of Tool Mark Comparisons Obtained Using a 

Quantitative, Comparative, Statistical Algorithm‖ Journal of Forensic Sciences, Volume 

55, Number 4, July 2010, pp. 953-961.

Bachrach B., Jain A., Jung S., and Koons R.D., ―A Statistical Validation of the 

Individuality and Repeatability of Striate Tool Marks: Screwdrivers and Tongue and 

Groove Pliers‖, Journal of Forensic Sciences, Volume 55, Number 2, March 2010, pp 

348-357.

Bacharach, B., ―Statistical Validation on the Individuality of Tool Marks Due to the Effect 

of Wear, Environment Exposure and Partial Evidence‖, NIJ/NCJRS Document #227929, 

August, 2009.

Wever, G., et al. (2011). ―A Comprehensive Statistical Analysis of Striated Tool Mark 

Examinations Part 2: Comparing Known Matches and Known Non-Matches using 

Likelihood Ratios.‖ AFTE Journal, Vol. 43, No. 2. pp 137-145.

Abstract: A potential model for increasing the objectivity in the interpretation of 

toolmarks is explored using consecutively matching striae (CMS) and Bayesian 

inference. Given the nature of the data, standard statistical thinking suggests that 

Bayesian inference is likely to be the most powerful method of interpretation. The 

unavoidable paucity of data for high CMS runs for the known non-match 

condition is handled using a small advance in modelling. The resulting likelihood 

ratios show some, but incomplete separation between the known match and 

known non-match conditions. Although promising, the resulting incomplete 

separation between known match and known non-match is thought to represent 

limitations of the CMS summary of the complete pattern and limitations of the 

modeling used.

Buckleton, J., et al. (2005). ―An Exploratory Bayesian Model for Firearm and Tool Mark 

Interpretation.‖ AFTE Journal, Vol. 37, No. 4. pp 352-361.

Abstract: An exploratory Bayesian model for the interpretation of striated tool 

marks has been developed. This model is based on a consecutive matching 

striae (CMS) summary of the visual image of a striated tool mark comparison. 

The results of applying this model to two data sets are encouraging.

Champod, C., et al. (2003). ―Firearm and Tool Marks Identification: The Bayesian 

Approach.‖ AFTE Journal, Vol. 35, No. 3. pp 307-316.

Abstract: We have read with interest the paper written recently by Bruce Moran in 

the AFTE Journal and the exchange of letters in INTERface. The author is a 

respected commentator in the field of firearm and tool mark examination. He 

challenges readers to demonstrate the practical applicability of Bayes theorem in 

firearms and tool mark examination. Mr Moran discusses an «objective» criterion 

such as consecutive matching striae (CMS) and it‘s applicability to firearms and 

June 14, 2011 9090
tool marks examination. Notably he suggests the adoption of the consecutive 

matching striae numerical criterion for identification which (in the author‘s words) 

―establishes a clear threshold between identification and non-identification in 

striated tool marks, because it is based on scientific principles and sound 

empirical research‖. He also declares that ―Bayes theorem is not appropriate as 

an effective means to interpret the identification science‖.

Deinet, W., et al. (2007). ―Comments on the Application of Theoretical Probablity 

Models including Bayes Theorem in Forensic Science Relating Firearm and Tool 

Marks,‖ AFTE Journal, Vol. 39, No. 1. Pp 4-7.

Abstract: The comparison of firearm and tool marks is of great importance in 

forensic science. Examiners magnify the marks using a microscope and decide, 

on the basis of their experience, whether the degree of similarity is sufficient for 

an identification. One aim of scientific research is to develop probability models 

to make objective and reproducible results possible. In this paper comments are 

made on the application of Bayes‘ rule. Additionally, the extent to which an 

objective description of forensic science evidence is possible by the application 

of probability models is discussed.

Taroni, F., et al. (1996). ―Statistics: A Future in Tool Marks Comparison?‖ AFTE Journal, 

Vol. 28, No. 4. pp 222-232.

This article discusses the uses of statistics and the possible use of statistics by 

the field of Firearm and Toolmark Identification.

Deschenes, M., et al. (1995). ―Statistics and Tool Marks Comparisons.‖ AFTE Journal, 

Vol. 27, No. 2. pp 140-141.

This paper suggests how statistics can be utilized in toolmark comparisons but 

also the limitations of using them.

Biedermann, A., Bozza, A., and Taroni, F. (2008). ―Decision Theoretic Properties of 

Forensic Identification: Underlying Logic and Argumentative Implications.‖ Forensic 

Science International, Vol. 177. pp 120-132.

Abstract: The field of forensic science has profited from recent advances in the 

elicitation of various kinds probabilistic data. These provide the basis for 

implementing probabilistic inference procedures (e.g., in terms of likelihood 

ratios) that address the task of discriminating among competing target 

propositions. There is ongoing discussion, however, whether forensic 

identification, that is, a conclusion that associates a potential source (such as an 

individual or object) with a given item of scientific evidence (e.g., a biological 

stain or a tool mark), can, if ever, be based on purely probabilistic argument. With 

regard to this issue, the present paper proposes to analyze the process of 

forensic identification from a decision theoretic point of view. Existing probabilistic 

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inference procedures are used therein as an integral part. The idea underlying 

the proposed analyses is that inference and decision are connected in the sense 

that the former is the point of departure for the latter. As such the approach forms 

a coordinated whole, that is a framework also known in the context as  ̳full 

Bayesian (decision) approach‘. This study points out that, as a logical extension 

to purely probabilistic reasoning, a decision theoretic conceptualization of 

forensic identification allows the content and structure of arguments to be 

examined from a reasonably distinct perspective and common fallacious 

interpretations to be avoided.

Meyers, C. (2002). ―Some Basic Bullet Striae Considerations.‖ AFTE Journal, Vol. 34, 

No. 2, pp 158-160.

Abstract: The purpose of this paper is to review some of the basics of striae 

formation on fired bullets and the often present problems in their replication and 

subsequent attempts at quantification. Methods of quantifying bullet striae along 

with a slightly different view of percent match will be mentioned.

Stone, R. (2004). ―A Probabilistic Model of Fractures in Brittle Metals.‖ AFTE Journal, 

Vol. 36, No. 4. pp 297-301.

Abstract: The examination and comparison of fracture evidence has often fallen 

within the purview of firearm/toolmark examiners. Little has been published 

concerning the individuality or probabilistic examination of this type of evidence. 

Traditionally, examinations have been based on ―common sense‖ and the 

―feeling‖ or ―assumption‖ that ―two things that match this well couldn‘t have 

originated from separate objects or separate breaks‖. This study will focus on 

how such two and three dimensional fractures form in brittle metals and will 

present derived mathematical probability models for them. It also presents a 

model that, with validation, would allow examiners to quantify such fractures in 

actual casework.

Claytor, L.K., and Davis, A.L. ―A Valdiation of Fracture Matching Through the 

Microscopic Examination of the Fractured Surfaces of Hacksaw Blades.‖ AFTE Journal, 

Vol. 42, No. 4. pp. 323-332.

Abstract: During a fracture, an object separates into two or more parts; fracture 

matching is the association of those surfaces to each other. Forensic fracture 

matching relies on the principle that no two objects fracture identically. The 

authors hope to further support this principle by studying the topography of 

fractured hacksaw blades. Two consecutively manufactured hacksaw blades 

were each fractured eleven times and inter-compared. Two hundred fifty-three 

topographical comparisons were conducted between 44 fractured edges; each 

fracture produced two surfaces discernable from any other. In addition, a series 

of proficiency style tests were made from consecutively manufactured blades and 

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sent to participants throughout the United States and abroad. A total of 66 

answer sheets were returned, providing 330 test results for evaluation. A 

comprehensive list of 49 references is included.

Uchiyama, T. (1992). ―The Probability of Corresponding Striae in Toolmarks.‖ AFTE 

Journal, Vol. 24. No. 3. pp 273-290.

Abstract: Two significant and practical corresponding relationships used to 

compare and determine the common origin of striated toolmarks are the number 

and quality of corresponding striae. It is essential to know how many striae can 

correspond by chance in order to determine the discriminating power of these 

relationships. The probability of chance correspondence (i.e., % match), and the 

maximum number of consecutively matched striae was estimated for variation in 

the density of the striae, the critical coincidence ratio (CCR), and the width of the 

striae of the marks compared. The critical coincidence ratio is a measure of how 

each specific striae compared is counted as corresponding or not corresponding. 

The results generated by this simulator study will be used to evaluate the 

discriminating power of these relationships and allow the implementation of 

effective and efficient automated systems applied to the comparison of real 

striated toolmarks. Automated comparison systems applied to real striated 

toolmarks (ie., fired bullets) will in turn allow comparisons on a scale sufficient to 

establish and validate objective criteria for the comparison of striated toolmarks 

to determine common origin.

Kaye, D. (2010). ―Probability and Individuality in Forensic Science Evidence.‖ Brooklyn 

Law Review, Vol. 75, No. 4, pp. 1163-1185

Abstract: Day in and day out, the testimony of criminalists reflects the paradigm 

of positive, uniquely specific identification of fingerprints, DNA profiles, bullets, 

handwriting, and other trace evidence. Commentators from other disciplines have 

called for a ―paradigm shift‖ that would replace talk of individualization with 

statements of probabilities or would exclude certain testimony pending better 

research on the ability of analysts to perform as claimed. With rare exceptions, 

however, the courts have failed to perceive the gap between optimistic theory 

and hard proof, and they have accepted weak forms of validation. Now that 

Congress has called on the National Academy of Sciences to ―disseminate best 

practices and guidelines concerning the . . . analysis of forensic evidence,‖ a 

new opportunity to reassess the long-entrenched claims of individualization is at 

hand. This essay seeks to contribute to such a reassessment by examining the 

arguments of two of the most powerful critics of this aspect of forensic science, 

Professors Michael Saks and Jay Koehler. The ―individualization fallacy‖ they 

describe implicates issues in philosophy, logic, mathematics, psychology, and 

statistics. This essay argues that contrary to one possible reading of their work, 

there is no rule of logic or ontology that prevents individualization and that 

testimony as to uniqueness is acceptable in some situations. It suggests a 

June 14, 2011 9393
combination of evidentiary rules and practices to avoid the excesses of the 

current form of testimony.

Kirk, P. and Kingston, C. (1964). ―Evidence Evaluation and Problems in General 

Criminalistics.‖ Journal of Forensic Sciences, Vol. 9, No. 4. Pp 434-444.

Authors discuss the ideas of objectivity and subjectivity and the role statistics 

plays in forming the foundation of identification conclusions. Although the articles 

addresses more general criminalistics issues, firearms identification fits within the 

broad range of topics being discussed.

Biasotti, A. (1964). ―The Principles of Evidence Evaluation as Applied to Firearms and 

Tool Mark Identification.‖ Journal of Forensic Sciences, Vol. 9, No. 4. pp 428-433.

The author discusses the current state of firearm and toolmark identification by a 

review of the literature. He also addresses the issue of more objective standards 

in the field to form a conclusion of identification. The author discusses probability 

and statistical models as a possible approach to more objective standards.

Gunther J.D., and Gunther C.O, "The Identification of Firearms", Wiley & Sons, Inc. 

1935. pp 33-36.

The authors discuss a basic probability model for determining the individuality of 

a firearm. They looked at the random chances of particular individual / accidental 

characteristics in determining how ―unique‖ a particular firearm signature was. 

They also discuss the concepts of a mark being so unique that it will be 

differentiated from all other firearms.

Hatcher, J., Jury, F., and Weller, J. "Firearms Investigation Identification and Evidence."

Small-Arms Technical Publishing Company, 1935. (reprint 2006 – Ray Riling Arms 

Books Company) pp 376-381.

The authors discuss basic concepts and ideas of probability models being used 

in firearms identification to determine how likely a particular firearm was 

responsible for firing a particular bullet / cartridge case. They base their 

discussion in this text on the theory of probabilities and clearly state that their 

estimates of a numerical probability is strictly theoretical. 

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