New Gun Imaging Database Reference Material

The Association of Firearm and Tool Mark Examiners was founded in 1969 as an organization to promote the exchange of information in the field of Firearms Identification.

To that end, the following reference material has been listed on the subject of New Gun Imaging Database that has been touted as a tool to aid law enforcement in reducing gun related violent crime.

Forensic Firearm Examiners traditionally testify in court and are obliged to correct slang terms that are not correct. The news media and some legislative leaders have coined the term "Ballistic Fingerprinting." Firearm Identification, not Ballistics, is the scientific discipline related to the matching of fired bullets and cartridge cases to a gun because of impressions and striations imparted on them. These are not fingerprints, nor DNA, and still require manual examination utilizing a comparison microscope by a trained firearm examiner before providing testimony in court.

This reference information is provided to assist interested individuals as a resource of accurate reports, articles and issues on the subject. While the association has no political position on the subject of a New Gun Imaging Database, we hope this resource will provide factual information for responsible discussion of the issue so that decisions made will be informed choices.

  Index

REPORTS

Frederic A. Tulleners, Laboratory Director, Bureau of Forensic Science, California Department of Justice, Technical Evaluation: Feasibility of a Ballistics Imaging Database for All New Handgun Sales (October 5, 2001) www.nssf.org/PDF/TechnicalEvaluation.pdf

Jan De Kinder, Review AB1717 Report. Technical Evaluation Feasibility of a Ballistics Imaging Database for All New Handgun Sales, www.nssf.org/PDF/DeKinder.pdf  

Robert M. Thompson, Jerry Miller, Martin G. Ols, and Jennifer C. Budden, National Integrated Ballistic Information Network; Bureau of Alcohol, Tobacco and Firearms, U.S. Department of the Treasury, Ballistic Imaging and Comparison of Crime Gun Evidence by the Bureau of Alcohol, Tobacco and Firearms (May 13, 2002)

Forensic Technology Inc., Comments of Forensic Technology, Inc. on the Technical Evaluation: Feasibility of a Ballistics Imaging Database for All New Handgun Sales (2002)

David B. Kopel, J.D. and H. Sterling Burnett, Ph.D., Ballistic Imaging: Not Ready for Prime Time (April 30, 2003), National Center for Policy Analysis, Policy Backgrounder No. 160 (* Inaccurate information within article)

William C. Boesman and William J. Krouse, Congressional Research Service, National Integrated Ballistic Information Network (July 3, 2001) (Order Code RL31040)

Jan De Kinder, Ballistic Fingerprinting Databases, Science & Justice, Vol. 42, No. 4 (2002) 197-203

Terrance A. LaVoy, Effects of Modern Technology of Firearms Identification, Michigan State University Press, (1979)

Jon D. Tew, Incorrect Manufacturer Supplied Test Fire Cartridge Cases, AFTE Journal, Pending Publication (2002)

Daniel W. Webster, ScD, MPH, Johns Hopkins Center for Gun Policy and Research, Comprehensive Ballistic Fingerprinting of New Guns: A Tool for Solving and Preventing Violent Crime, October 2002

State of California Assembly Bill No. 1717, Chapter 271, Firearms: ballistic testing. (2002)

State of New Jersey Assembly Bill No. 438, October 29, 2002

Bill Twist, "Erasing Ballistic Fingerprints", PlanetTimes.com

The New York Times, "Rethinking Ballistic Fingerprinting", (November 11, 2002)

Jeff Johnson, CNSNEWS.COM, "Police Challenge Gun Control Advocates on Ballistic Imaging", October 29, 2002 (* Inaccurate information within article)

American Broadcasting Company, ABCNEWS.COM, "Ballistic Fingerprinting", October 16, 2002 (* Inaccurate information within article)

Steven Milloy, Fox News, "How Reliable Is Ballistic Fingerprinting?", October 18, 2002

Documented Research Relating to Consistency of Toolmarks on Fired Bullets*

Lutz, Monty, "Consecutive Revolver Barrels", AFTE Newsletter 1970 Aug;24-28 - study of toolmarks from consecutively manufactured barrels. two 38 SPL barrels. Able to identify individualistic signature of both barrels. Described land impressions but not groove impressions.

Skolrood, R.W., "Comparison of Bullets fired from Consecutively Rifled Cooey .22 Caliber Barrels", Canadian Society of Forensic Science Journal 1975;8(2):49-52 - additional work on Cooey 22 caliber rifles to test conclusions made by Churchman in 1949.  Noted, An carry over.

Freeman, Ray, "Consecutively Rifled Polygon Barrels", AFTE 1978 Jun;10(2):40-42 - three consecutively rifle H&K 9mm Luger polygonally rifled barrel study. Noted that each barrel had it's own distinct and separate individuality.

Murdock, John, AA General Discussion of Gun Barrel Individuality and an Empirical Assessment of the Individuality of Consecutively Button Rifled .22 Caliber Rifle Barrels, AFTE 1981 Jul; 13(3):84-111 - extensively researched paper studying gun barrel individuality and empirical assessment of button rifle barrels. Assessed individuality of consecutively manufactured button rifled 22 caliber rifle barrels. Did not note any significant agreement in non-match positions of inter comparisons conducted with test fires from this rifle including subclass carryover. Extensive treatment of various rifling methods. Noted the persistence of subclass features in the groove impression areas from barrels fired from scrape cutter, hook cutter, and gang broach rifling methods and that identifications are much more reliable when based on toolmark comparisons from the un-cut land areas. Described toolmark finishes from non-cut processes (button, mandrel, hammer forge) as well.

Hall, Earl E., "Bullet Markings from Consecutively Rifled Shilen DGA Barrels", AFTE 1983 Jan;15(1):33-47 - performed study of consecutively rifled barrels with polygonal rifling. 4 Shilen DGA barrels. First initial test shots could not be identified to one another. (Supports rapidly changing "new barrel" phenomena) 31 test fires from each of four barrels. "With bullets closely related in the firing sequence the dissimilarity of marks created by any two different barrels is significantly greater than the dissimilarity seen on bullet pairs that are from the same barrel".

Matty, William, "A Comparison of Three Individual Barrels Produced From One Button Rifled Barrel Blank", AFTE 1985 Jul;17(3):64-69 - study of individuality of three revolvers all cut from same section of rifled tube. "To ascertain the possibility of carry-over effects from imperfections on a rifling button, the following "worst case" experiment was devised. Three .30 caliber revolver barrels, all cut from the same section of rifled tube, were supplied by George Wilson III of the Wilson Arms Company. They were machined at Sturm, Ruger to fit the Ruger .30 Carbine New Model Blackhawk revolver. The machining consisted of tapering, threading, crowning, and cutting the forcing cone. The barrels were all machined in the same orientation; no barrel is reversed with respect to he direction of bullet passage. Bullets fired from these barrels would be as alike as possible while still being fired form different barrels". Examined Mikrosil casts of barrels first then test fired. Observed no significant carry over of sub-class in casts in lands but numerous longitudinal striations on the groove impressions caused by button imperfections that persisted in some cases along the entire length of all three barrels. Test bullets from these barrels exhibited "sufficient carryover for phasing but not enough for conclusive identification". No subclass carry over in land impressions at all.

Brundage, David, "The Identification of Consecutively Rifled Gun Barrels", AFTE 25^th Seminar; 1994 Jun 5-10; Indianapolis (IN), AFTE Journal, 1998, Summer, Vol. 30, No. 3, pp 438-444 - sent test fires from 10 consecutively rifle barrels to 30 labs in country to see if examiners could correctly phase. Also provided 15 unknowns with at least one each of the 10 barrels represented for comparison. All examiners successfully associated the unknowns with the barrel from which they were fired.

Miller, Jerry, "An Examination of Two Consecutively Rifled Barrels and a Review of the Literature", AFTE 2000; 32(3);259-270 - Miller produced striated toolmark test samples by pushing two copper jacketed bullets and two lead bullets through each barrel after Mikrosil casting each barrel. He evaluated the resulting striated marks on these bullets for the presence of subclass influence and according to the proposed conservative numerical criteria for identification of striated toolmarks proposed by Biscotti and Murdock in 1997. Miller made the following conclusions:

• "Both barrels show significant reproduction of subclass carryover within the land impressions that are more significant than in the groove impressions"
• "Examination of bullets pushed through barrels show that those subclass characteristics did not transfer sufficiently to bullet surface to interfere with ID of striae on bullets with correct barrel"

• "There is a significant occurrence of consecutive groups of 2X striae in all categories with larger groups appearing in only known matches"

• "If only single land impressions are considered, with the conservative criteria for identification applied, no erroneous identifications could be made. Some missed identifications could occur"

• "If all of available land impressions are considered when applying conservative criteria for identification, fewer missed identifications could occur, and no erroneous identifications will be made"

• "An examination of barrels in this study shows remarkable carryover of sub class characteristics from one barrel to next but is not imparted to the bullet that passes over these surfaces"

• "Applying the "conservative numerical criteria for identification" demonstrated that, after elimination of subclass influence, no erroneous identifications could be made between bullets from two consecutively rifled barrels"

This study further validates that the use of the conservative numerical criteria for critical evaluation of striated toolmark agreement will not result in a false identification. Further, it is quite possible to conclude an identification even with the potential presence of subclass carryover as long as the significance of this influence has been sufficiently evaluated.

Miller, Jerry, "An Examination of the Application of the Conservative Criteria for Identification of Striated Toolmarks Using Bullets from Ten Consecutively Rifled Barrels", AFTE 2001;33(2);125-132 - Miller intercompared bullets test fired from ten consecutively manufactured gun barrels to determine if "1.) they could be identified to the barrel which fired them; 2.) the presence of similar toolmarks on bullets fired from different barrels which could be attributed to subclass characteristics between the barrels; and 3.) the propriety of the proposed "conservative criteria for identification." Miller concluded "although some striae present in the land and groove impressions of the bullets fired from consecutively rifled barrels could be the result of subclass influence, none of these features affected the correct identification of the bullets. None of the areas examined between different bullets were of sufficient quality to lead to a miss-identification. In fact it was difficult to find areas that could be considered as having been produced by a subclass source." By "applying the Biasotti and Murdock conservative numerical criteria for toolmark identification, a significant difference can be seen between a known match and known non-match comparison. Considering the results of the data for the two and three-dimensional comparisons between known matches and non-matches, no erroneous identifications would be expected, although some actual identifications would be excluded." This experimentation is significant in that it applies the CMS numerical criteria to the traditional "worst case" scenario type of testing that has been historically performed over the last 50 years using the traditional subjective evaluation and closely validates this kind of testing from a more objective approach. This study further validates that the use of the conservative numerical criteria for critical evaluation of striated toolmark agreement will not result in a false identification.

Matty, William and Johnson, Torrey, "A Comparison of Manufacturing Marks on Smith and Wesson Firing Pins", AFTE 1984 Jul;16(3):51-56 - examined consecutively manufactured firing pins from Smith and Wesson K-frame revolvers. Described lathe-turning operation used in producing finish on firing pins. Compared using direct comparison, lead impressions and fired casings with firing pin impressions. Machining marks offered presence of subclass features and concluded that random defects coincidental had to be present to effect identification.

Matty, William, "Raven .25 Automatic pistol Breech Face Toolmarks", AFTE 1984 Jul;16(3):57-60 - assessment of consecutively tooled Raven 25 Auto Breech faces. Described milling process used to surface these tools. Used six bolts consecutively manufactured and three additional consecutively produced bolts an hour later. Concluded that each bolt could be identified to itself when offset by 180 degrees. But there was no agreement among the different breech faces.

Uchiyama, Tsuneo, "Similarity Among Breech Face Marks Fired From Guns with Close Serial Numbers", AFTE 1986 Jul;18(3):15-52 - study of breech face comparisons using firearms close in serial number. (serial numbers does not necessarily correlate to consecutively manufactured firearms) Presented excellent photos of known non-matches depicting agreement of the coarser striated markings on breech face marks from 25 Auto Browning pistol (straight breech face finish) and 25 Auto Raven pistol (concentric circle finish). Contained significant amount of known non-match comparisons that were photographically documented. No significant agreement was noted among toolmarks produced by these weapons. Suggested that comparisons should be rated by "probabilistic scaling".

Thompson, Evan, "Phoenix Arms (Raven) Breech Face Toolmarks", AFTE 1994 Apr;26(2):134-135 - study similar to Matty's study of breech faces of Raven firearms. Wanted to know if there was any effect in manufacturing due to change in ownership (Raven to Phoenix). Obtained four randomly selected barrels in batch of 60,000. Each milled and with concentric circular markings on breech faces. Compared Mikrosil casts as well as fired cases. All four tools were distinguished without a problem. However, of the fired cartridge cases due to poor quality markings, there was insufficient markings to exclude any of the four bolts as having produced the markings on any of the four cases. Confirmed need to look at situation theoretically but in a practical manner as seen in casework as well.

Lardizabal, Peter P., "Case Study of the Heckler and Koch USP", AFTE 1995 Jan;27(1):49-51 - examined correspondence of breech faces of Heckler and Koch. 40 S&W pistols. Two with sequential serial numbers and sequentially manufactured. Bolts broached. Cartridge cases fired from these pistols exhibited poor quality markings. However, significantly corresponding markings (which were coming from a toolmark above the firing pin hole appearing to have been made after the finishing process) were noted between the two sequentially manufactured pistols breech faces just above the firing pin and persisted after over 250 test firings. No other marks could be used to identify a casing to one of the two firearms. Cartridge cases fired from the firearm with lower serial number demonstrated no correspondence to the other two weapons.

Shem, Robert J. and Striupaitis, Peter P., "Comparison of 501 Consecutively Fired Bullets and Cartridge Cases From a 25 Caliber Raven Pistol", AFTE Journal, Vol. 15, No. 3, 1983, p. 109. This article describes the research undertaken to examine the consistency of toolmarks on fired bullets and cases, and concluded that they could be identified for 500 samples of firing.

Ogihara, Yoshimitsu, et al, "Comparison of 5000 Consecutively Fired Bullets and Cartridge Cases From a 45 Caliber M1911A1 Pistol", AFTE Journal, Vol. 15, No. 3, 1983, p. 127. This article describes the research undertaken to examine the consistency of toolmarks on fired bullets and cases, and concluded that they could be identified for 5000 samples of firing.

Altered Areas of Firearms

Molnar, S., "Identification of Homicide Bullets to a Gun Barrel Section", AFTE Newsletter, #3, 1969, p. 29. #9;A firearm was dismantled and sawed into pieces and thrown into a river. A barrel section was recovered. This section was threaded and screwed onto a new frame for test firing. "Some individual type characteristics were lost in sawing of the barrel, and a few new ones created in the machining process, but it did not prevent identification."

Garrison, Todd, "Rifled Barrel Altered to a Smoothbore Produces Unusual Results", AFTE Journal, Vol. 23, No. 4, October 1991, pp 928-930. An attempt was made to remove the rifling in a barrel by drilling. Test bullets fired through this barrel displayed no land or groove impressions, but imperfections within the barrel caused by the drilling produced identifiable striae. In addition, two chambers of the cylinder were flared out from damage. This area produced identifiable striae on the bullets as they left the cases and entered the barrel.

Murdock, John, "The Effects of Crowning on Gun Barrel Individuality", Journal of Forensic Science Society" Vol. 12, #9;1972, p. 305. #9;This article describes a study that was done to examine how any change of the surface area at the muzzle of a firearm might affect any toolmarks imparted to the bullet as it exited the barrel, and whether any change present might affect subsequent identifications. The end of a barrel muzzle is finished by crowning, which is a process that removes material from the muzzle to protect the ends of the rifling from impact and make the end of the bore absolutely true and square. A firearm from four manufacturers was studied. Bullets were fired through the barrels, re-crowned, and test fired again, three of the four barrels were then re-crowned, and test fired again. During each re-crowning, it was noted that a 1/8" of material was removed each time. The test bullets from each re-crowning were intercompared with each other. This altering of the barrel in this area revealed that, "although some changes in striation pattern were observed on test bullets which were separated by a re-crown; sufficient agreement was noted to enable an identification to be effected."

Sorensen, Williams, "Barrel Corrosion and it's Effect on Identification", AFTE Newsletter #13, 1971, pp 34-41. This research was done to examine the effects of corrosion on the areas of firearms that produce toolmarks on fired ammunition, and how long it takes for this corrosion to occur. They concluded that the depth of submersion has an effect on the speed of corrosion, with it occurring more quickly at shallower depths. Salt water had a greater effect on the operating condition of the firearm over fresh water submersion, however, after about two weeks of submersion, it didn't matter. There was no detectible difference in the barrel corrosion, both salt and fresh water were fast, but generally it concluded that 9 day's of submersion caused sufficient corrosion to preclude identification with pre-submersion exhibits.

Dodson, Ron and Stengel, Richard, "Bullets, Marked Before Firing", AFTE Journal, Vol. 24, No. 4, October 1992, pp. 354 B 355. This article depicts a case in which the bullets of cartridges were gouged and damaged prior to firing, in order to create toolmarks that would preclude identification with any toolmarks caused by subsequent firing through a barrel. Their tests showed that the toolmarks were over-scored by the rifling and barrel when fired, and the bullets could be identified to the firearm.

Santora, David, "A Study of The Effects an Unrifled Barrel Has on Forensic Evidence", AFTE Journal, Vol. 29, No. 3, summer 1997, pp. 365-368. This article discusses the results of an identification of bullets fired through a barrel that left the factory without being rifled. They concluded that the manufacturing processes that were completed up to that point left striae on a fired bullet that was sufficient to support an identification.

Thompson, Evan, "Aluminum Barreled 380 Caliber derringer", AFTE Journal, Vol. 32, No. 1, winter 2000, pp. 48. This article discusses the examination of bullets fired from an aluminum barrel in which the rifling tolerances were such that no discernable land and groove impressions were observed. No identifications were made.

Molnar, S., "Unusual Barrel Engravings on Bullet", AFTE Journal, Vol. 11, No. 4, 1979, pp. 38. This article discusses the identification of bullets fired through a barrel in which the drilling and tapping process for vented rib screws created two projections in the barrel that created additional toolmarks.

Miller, Jerry, "Chamber Marks From Dry-Fire Damage", AFTE Journal, Vol. 24, No. 2, April 1992, pp. 162-164. This article describes toolmarks that are imparted to a bullet as it is inserted into the chamber of a revolver caused by a protrusion of metal into the chamber. The protrusion of metal is caused by the impact of the firing pin hitting the edge of the chamber during "dry-firing". It was found that passage of the bullet through the barrel over-scored the "chamber" toolmarks and did not preclude an identification.

Miller, Jerry, "Accidental Marks on a Fired Bullet From an Arminius Revolver", AFTE Journal, Vol. 28, No. 2, April 1996, pp. 80-81. This article describes toolmarks on a bullet fired through a barrel in which a front sight screw, protruding into the barrel, creates an unusual toolmark. This did not preclude the identification of the bullet.

Stengel, Richard, "Has Colt Gone Back to Making Shotguns?" AFTE Journal, Vol. 9, No. 2, 1977, pp. 187-191. #9;This article describes a firearm that left the factory without being rifled. Toolmarks produced on a fired bullet could still be identified.

Welch, Nelson, "Pardon Me, Your Rifle is Unbuttoned", AFTE Journal, Vol. 10, No. 2, 1978, pp. 27. This article discusses a firearm that left the factory prior to being rifled. It describes some toolmarks imparted to fired bullets, but that an identification could not be made.

Royse, Dan, "Identification Made on a Bullet Fired from an Unrifled Pistol", AFTE Journal, Vol. 27, No. 3, July 1995, pp. 197-199. This article describes a case in which a firearm was received without any rifling. Test fired bullets showed unique and reproducible toolmarks that were subsequently identified to an evidence bullet.

Thompson, Jim, ET. Al., "A Colt .45 Cup Smoothbore?" AFTE Journal, Vol. 24, No. 4, October 1992, pp. 352. This article discusses a firearm that left the factory prior to being rifled. It describes some toolmarks imparted to fired bullets, but that an identification could not be made.

Chenow, Richard, "A Smooth Bore Auto Pistol", AFTE Journal, Vol. 9, No. 2, July 1977, pp. 154-156. This article describes a firearm that left the factory without being rifled.  Toolmarks produced on a fired bullet could still be identified.

Baney, Ralph, "A Smooth Bore Tanfoglio Pistol", AFTE Journal, Vol. 24, No. 2, April 1992, pp. 177-178. This article describes a firearm that left the factory without being rifled.  Toolmarks produced on a fired bullet could still be identified.

Vaughn, Rick and Gilman, Phil, "An Identification With a Smoothbore Rifle", AFTE Journal, Vol. 15, No. 4, October 1983, pp. 19. This article describes a firearm that left the factory without being rifled. Toolmarks produced on a fired bullet could still be identified.

Arrowood, Michael, "A Smooth Bore Pellet Rifle", AFTE Journal, Vol. 6, No. 3, June 1974, pp. 3. This article describes the toolmarks caused by the imperfection inside a smooth pellet gun barrel, that reproduced identifiable toolmarks.

Lomoro, Vincent, "A Sako .38 Spl Cartridge With Grooved Bullet", AFTE Newsletter #2, 1969, p. 27. This article describes a manufactured bullet that has 12 grooves slanted left. These grooves are not removed by subsequent firing. No indication is made concerning it's effect on the identification.

*Information adapted from references provided by Bruce Moran

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