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; in that, applied science focuses on 

practical applications with less emphasis on the most basic objects and forces. 

The origination of toolmarks in the forensic science discipline of Firearms and Toolmark 

Identification (FA & TM ID) is derived from the validated theories in the physical sciences. 

Specifically, the origination of toolmarks in nature is based on previously established 

theories, principles and properties from the physical sciences that were also earlier 

adapted in the material, as well as the 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 

 C. Force(s) 

 1. Compression 

 2. Torsion 

 3. Shear 

 4. Tensile 

 5. Flexure 

IV. 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 

V.) 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 

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 

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 
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. 

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

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

Volume 13, Number 3, Pp. 34 – 61. 

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 , Volume 13, Number 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. 

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. 

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.
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., “Firearms and Toolmark Identification Criteria: A Review of the 

Literature”, Journal of Forensic Sciences, Volume 42, Number 3, 1997, pp.446-74. 

 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., 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 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. 

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. 

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. 

Association of Firearm and Toolmark Examiners 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 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 major working edges of a pistol. 

4. As manufacturing techniques and materials change over time, what 

studies have been performed to validate or invalidate older foundational 

studies? 

Lutz, M., (1970) Consecutive Revolver Barrels . Association of Firearm and Toolmark 

Examiners Newsletter #9, Page 24. 

Matty, William. (1984) Raven .25 Automatic Pistol Breech Face Tool Marks. Association 

of Firearm and Toolmark Examiners Journal, 16:3 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. (2009) The Identification of Consecutively Manufactured Extractors, 

Association of Firearm and Toolmark Examiners Journal, 41:3, 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. (2009) The Identification of Bullets Fired from 10 

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

Participants from 20 Countries. Association of Firearm and Toolmark Examiners Journal 

41:2 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 [1]. 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 û including the 

original 67 reported on by Brundage û was published by Hamby and Thorpe 

in 2001 [2]. This paper reports the final conclusions of the research 

conducted by Brundage, Hamby and Thorpe over a 10 year period [3, 4]. 

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. 
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, Rocky. (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 marks of “reasonable complexity” that the odds of the same 

marks being repeated on another tool to be 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. 

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 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 (NKM’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. 

Conducted pioneering study on striated type toolmarks on numerous cutting 

tools, especially knives, with working edges containing some type of grinded 

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. 

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 marks of “reasonable complexity” that the odds of the same 

marks being repeated on another tool to be astronomical. 

 

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 Association 

of Firearm and Toolmark Examiners Journal , Volume13, Number 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. 

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

Consecutively Manufactured Barrels Association of Firearm and Toolmark Examiners 

Journal 38:2 pp. 166 – 172. 

Forensic Technology challenged its newest 3D technology BulletTRAX3DTM 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 

Luger Hi-Point 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. 
Uchiyama, T., “Toolmark Reproducibility on Fired Bullets and Expended Cartridge 

Cases”, Association of Firearm and Toolmark Examiners 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. 

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?

 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. 

 These articles explore 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 r

 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. 
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? 

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. 

Association of Firearm and Toolmark Examiners 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 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 major working edges of a pistol. 
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? 

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. 

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.
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? 

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 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 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 

 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 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 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 I

 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 the groove I

 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. 

 Reported results of the comparison of jacketed and lead bullets fired from 

 two consecutively rifled barrels and that the markings on the bullets were I

 identifiable and unique to the barrel that fired them. 

 

Matty, William. “A Comparison of Three Individual Barrels Produced from One 

Button-Rifled 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 that 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 CMS 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 conservative 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 2) applied the conservative 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. 

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 barrel 

 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 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 which consisted of both 

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

 reported. 

 

Tulleners, Fred and Mike Guisto. “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 

 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. 

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.
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 cased 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 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. 

 

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 subclass and individual characteristics. 

 Results of these comparisons found that the manufacturing processes 

 used to fabricate these breechfaces produced 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 comprised 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 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. 

Study of cartridge cases fired from 617 different Glock pistols were 

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: 

‘Pre-Identified 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 along. 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 possible unless ID 

 on wear or 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 consecutively manufactured cartridge cases, with 

 each known specimen having at least one unknown specimen associated 

 with it. 

 Study showed that extractors could be distinguished from each other 

 despite that they were consecutively manufactured. 

 

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 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 encountered. 

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. 

 
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. 

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 effected 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 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 marks produced by 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. 

 

Lee, Susan E. “Examination of Consecutively Manufactured Slotted Screwdrivers.” 

AFTE Journal, vol. 35 (1), Winter, 2003, pp. 66-70. 

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 as 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 test was produced 

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 class 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. 

 

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 demonstrate 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 

(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 tire 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 their source. 

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:minimum-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 

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. 

 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. 

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. 
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 conservative 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. 
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. 

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 shows conclusively that an objective 

observer (a machine) detects significant visual differences between KNMs 

and KMs. 

 Miller, J. (2000). Criteria for Identification of Toolmarks, Part II: Single 

 Land Impression Comparisons. AFTE Journal, vol. 32 (2), 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 conservative criteria. 

Dongguang, L. (2006). Ballistics Projectile Image Analysis for Firearm 

Identification. IEEE Transactions on Image Processing, Vol 15, No. 10, 

2857-2865. 

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. 

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. 

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. 
14. What studies exist regarding the use of databases to facilitate an 

automated approach to analysis? 

 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, IS-5160. 

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 work-product (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. 

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. 

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. 

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. 

Banno, Atsuhiko, et al. (2004). Three Dimensional Visualization and Comparison 

of Impressions on Fired Bullets. Forensic Science International, 140, 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 impression 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. 
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. 

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. 

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. Further the authors 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. 

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 SelfOrganizing 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 decisionmaking strategy. The model also will make a 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. 

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 

 results)? Does research exist which identifies how and which cognitive 

 factors impact the analysis process? 

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. 

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. 

16. What studies exist which compare one toolmark analytical method to 

another? 

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. 

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. 

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, The Identification of Firearms and Forensic Ballistics, Butler & 

 Tanner 1934, Reprinted Barnes & Company 1962 and Wolfe publishing 

 1990 

 and 

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

 Sons, Inc. 1935. 

 These two 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. 

 and/or 

 Goddard, “Scientific Identification of Firearms and Bullets”, Journal 

 of Criminal Law and Criminology, Vol. 17, August 1926, pp 254-263. 

 Articles discuss the effectiveness of the microscopic comparative 

 method. 
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? 

 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. 

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. 

AFTE Glossary (1998). Theory of Identification as it Relates to Toolmarks. 

AFTE Journal, vol. 30 (1), 86-88. 

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". 

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 fired 

caliber bullets was conducted by using a computer to correlate the KM 
and KNM striae groups of these fired test 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. 

Uchiyama T. (1988). A Criterion for Land Mark Identification. AFTE

Journal, Vol. 20, No. 3, 236-251. 

Article describes the examination process of firearms identification 

beginning with class characteristic agreement and followed by individual 

characteristic agreement. Using a digital image processor is discussed for 

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, are only 

moderately low. 

18. What research has been completed, if any, to determine the threshold 

for identification (individualization)? 

AFTE Glossary (1998). Theory of Identification as it Relates to Toolmarks. 

AFTE Journal, Vol. 30, No. 1, pp. 86-88. 

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". 

 The threshold for identification is applied by individual examiners as 

 described by the AFTE Criteria for Identification. The success or failure of 

 the application can be assessed through scientific outputs or end- 

 products, such as Proficiency and Validity tests (see below). 

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

 Identification of Striated Toolmarks Using Bullets Fired from Ten Consecutively 

 Manufactured Rifled Barrels, AFTE Journal, Vol. 22, No. 2, Spring 2001, pp. 125-

 132. 
19. Does research exist which demonstrates that criteria for identifications 

(individualization) vary with method of manufacture or type of tool? 

None that is known. The AFTE Criteria is intended to be universal, accounting for all 

known methods of manufacture. 

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 #22. 

21. Do studies exist which demonstrate how often false negatives (e.g. a 

non-match 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% 

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, 

Internet Source: 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%

Reference: Murphy, Doug, Presentation at 2010 AFTE Training 

Seminar, and listed under Error Rate Documents at 

www.swggun.org.

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. 
Validity Tests- for short descriptions of each item, 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. 

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. 
22. Are there studies in toolmarks that identify what 

information/circumstances may bias an examiner's conclusion? 

No known studies address these specific issues 

23. Are there specific studies showing a difference in rate of inconclusive 

versus conclusive as a result of “contextual bias” information? 

No known studies address these specific issues (22, 23). 

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. 

 

25. What statistical research has been conducted and applied to firearm 

and toolmark examinations? What statistical models for firearms and 

toolmarks have been published? 

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. 

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.