642.1Firearm and Tool Mark Identification
- A properly qualified expert can analyze whether a certain type and caliber of gun (or one particular gun) fired the bullets connected to the crime. The witness can also verify that a particular firearm is operational, and may be able to estimate the distance from which the bullet was fired.
- An expert in tool mark analysis may also be able to examine markings left on or by other tools besides firearms (e.g., screwdriver, pry bar, or pliers), and give an opinion whether there is a match between a certain tool and a given set of marks.
- As with any other real evidence, the state typically needs to lay a proper foundation showing authentication and identification (i.e., that the gun introduced at trial is the same gun found and tested during the investigation) before offering the firearm into evidence.
- Forensic firearm and toolmark evidence has been admissible in North Carolina for many years and, despite some recent criticisms, it has frequently been admitted by other state and federal courts applying the Daubert standard as well.
Firearm Identification Overview
The firearms and tool mark identification section of the North Carolina State Crime Lab can perform tests and give expert testimony about the firearm matters discussed below.
What Type of Gun Was Used
If a bullet is removed from the victim’s body or found at the crime scene, the bullet can be examined to determine what type or make of gun could have fired it; this examination is often called a general “class characteristics” determination. See State v. Britt, 217 N.C. App. 309 (2011) (state’s expert witnesses were initially permitted to testify only that the bullets were “consistent” with a certain type of firearm – court later allowed additional testimony matching the bullets to a specific gun); State v. Crandell, 208 N.C. App. 227 (2010) (no error in allowing SBI agent to offer expert testimony regarding calibers of bullet recovered from the crime scene and victim's head, which were consistent with firearms seized in the case); see also State v. Moore, 301 N.C. 262 (1980) (bullet removed from victim “could have been fired from a .38 pistol” found at the crime scene).
Whether This Particular Gun Was Used
If a bullet is removed from the victim’s body or found at the crime scene and a particular gun is suspected of being involved in the crime or linked to the defendant, both may be examined and compared to determine whether the bullet was or was not fired from that particular gun, based on an a microscopic comparison of both “class characteristics” and “individual characteristics” of the two items. See State v. Alston, 294 N.C. 577 (1978) (admission of bullet and pistol was proper with testimony of firearms expert that bullet recovered from victim “could not have been fired from any other weapon” than pistol taken from defendant); State v. Dean, 196 N.C. App. 180 (2009) (ballistics evidence in murder trial established that the same weapon was used in a prior incident); State v. Anderson, 175 N.C. App. 444 (2006) (firearm identification expert’s testimony that bullets in the victim were fired from the gun recovered near crime scene was sufficiently reliable to be admitted under Rule 702); see also State v. McGraw, 243 N.C. App. 675 (2015) (unpublished), (similar ruling, decided under pre-Daubert version of Rule 702).
Condition/Operability of a Gun
A gun function test may be performed to determine whether a particular gun is operating properly. Such evidence may be relevant, for example, in an armed robbery case as proof that the weapon was actually capable of threatening or endangering the victim’s life, or as proof of the defendant’s claim that a gun may or may not have fired by accident or mistake, such as when the safety is broken.
A gun-function test can also be used to determine the amount of force or pressure necessary to pull the trigger or fire the gun. Such evidence might be relevant to a claim of self-defense or accident, or to determine the extent and possible cause of any gun malfunction. A gun-capacity examination may also determine how many rounds of ammunition a gun holds and how many shots may be fired without reloading. See State v. Brown, 64 N.C. App. 578 (1983) (ballistics expert was properly permitted to testify that six and one-quarter pound pull was required to pull gun’s trigger to cause it to fire); State v. Jones, 287 N.C. 84 (1975) (experiments performed on murder weapon to determine amount of force necessary to cause gun to fire was properly admitted; case contains good discussion about competency of such experimental evidence).
Distance from Gun to Victim
Gunshot residue tests (including a muzzle to target distance test) may be done to provide an estimate of how far the defendant was from the victim when the defendant fired. For this type of examination, the firearms identification section compares the pattern of gunshot residue on the victim’s clothing or skin to test patterns produced when the same ammunition used in the crime is fired from the defendant’s gun at a given distance. However, due to continuing improvements in ammunition powders and primers, usually only a small amount of gunshot residue will be deposited on clothing or other objects, so it has become more difficult to perform this type of analysis with modern ammunition. For more information on the admissibility of gunshot residue test results, see State v. Crowder, 285 N.C. 42 (1974) and the related expert witness entry on Gunshot Residue.
An examination of the nature of the victim’s wound may also provide evidence of the distance of the gun from the victim when fired, but this type of examination and resulting testimony would usually be done by a pathologist, rather than a firearms expert. A pathologist with the North Carolina Medical Examiner’s Office may be called to testify about gunshot wounds, subject to proper qualification as an expert. See State v. Pridgen, 313 N.C. 80 (1985) (pathologist testified about the location and number of gunshot wounds observed on the victim’s body, and was permitted to give an opinion about what kind of gun inflicted the wounds, the distance of the gun from the victim when the gun was fired, the paths of the bullets, the position of the body when the wounds were inflicted, and the time of death).
Admissibility and Daubert
Expert testimony about ballistics and firearm identification has been deemed admissible in North Carolina for many years (see cases cited above). Cases decided after the 2011 amendment to Rule 702 have continued to hold that this type of expert testimony satisfies the more stringent reliability requirements under the Daubert standard. See, e.g., State v. Miller, 852 S.E.2d 704 (N.C. App. 2020) (affirming admission of expert testimony matching shell casings to a firearm where "the trial court ruled that 'under Rule 702, the Court in its discretion finds ... that [Clardy's] testimony will be based upon sufficient facts and data,' 'is the product of reliable principles and method[s],' and that Clardy 'has applied these methods and principles to the facts of this particular case'”); State v. Griffin, 268 N.C. App. 96 (2019) (holding that firearm expert's opinion "was the product of reliable principles and methods, and that she reliably applied the principles and methods to the facts of the case" and therefore "the trial court did not abuse its discretion, much less plainly err, in admitting [the analyst’s] expert opinion testimony on forensic firearms examination"). A number of additional cases, both published and unpublished, demonstrate that firearms identification testimony is still routinely admitted at trial. See, e.g., State v. Kimble, 267 N.C. App. 629 (2019) ("A firearms and toolmark expert testified that the five projectiles recovered from the scene and from Burch’s body were fired from the same firearm"); State v. Stephens, 255 N.C. App. 215 (2017) (unpublished) (mentioning in dicta that “a ballistics expert determined the spent 9 mm casing found at the murder scene was fired from the weapon recovered in Stroud's bedroom”); State v. Sells, 242 N.C. App. 522 (2015) (unpublished) (evidence showed that pistol recovered near crime scene “was ultimately shown to be the pistol missing from Defendant's room, and—based on ballistics testing—the pistol used to murder Rummage and Lowder”); State v. Hutcheson, 233 N.C. App. 108 (2014) (unpublished) (“ballistics expert, testified that the bullet recovered from Mr. Parker's body had the same general class characteristics as the bullets test fired from Defendant's 9.0 mm handgun”).
Federal trial courts applying the Daubert standard have likewise allowed this expert testimony into evidence. See, e.g., U.S. v. Simmons, 2018 WL658693 (E.D. Va. 2018) (expert permitted to testify at trial that “she concludes, based on her knowledge and experience as a firearm and toolmark examiner, the same weapon fired certain recovered cartridge components”); U.S. v. Willock, 682 F.Supp.2d 512 (D. Md. 2010) (“The courts have permitted toolmark experts to conclude that shell casings and/or bullets were fired from a particular firearm. The Court will allow Esposito to opine that the gun found in Hebron's apartment fired the cartridge and bullet fragment recovered from the scene of Moore's murder,” but also noting that “[t]he parties have agreed that Esposito should not be permitted to express his opinions with any degree of certainty.”); U.S. v. Foster, 300 F.Supp.2d 375 (D. Md. 2004) (defendant’s objections to expert ballistic testimony “may be subjects for cross-examination, but they were not sufficient to render the proffered testimony unreliable under Daubert”); see also U.S. v. Caldwell, 182 Fed. Appx. 227 (4th Cir. 2006) (unpublished) (“a ballistics expert testified that the markings on the shell casings recovered from the crime scene matched those test fired from Caldwell's weapon”).
So what’s the issue?
Despite the abundance of cases in favor of admissibility, the defense may try to exclude this evidence based on recent criticisms of the discipline as a whole, such as those found in the President’s Council of Advisors on Science and Technology (“PCAST”) 2016 report, Section 5.5, pages 104-114, which concluded that more work needs to be done to determine the validity of the field. Some trial courts applying the Daubert test have restricted experts’ testimony in this area, such as only allowing the witness to testify that certain marks were “consistent with” or “could have” come from the weapon, but not allowing a witness to opine that he or she is “scientifically certain” it was the same gun. See, e.g., U.S. v. Glynn, 578 F. Supp. 2d 567 (S.D.N.Y. 2008); U.S. v. Green, 405 F. Supp. 2d 104 (D. Mass. 2005).
The North Carolina Court of Appeals addressed these reliability arguments in State v. Miller, 852 S.E.2d 704 (N.C. App. 2020) and affirmed the trial judge's decision to admit expert testimony matching shell casings to a firearm under Rule 702 and Daubert, holding that "despite some evidence from Miller challenging the reliability of this type of expert testimony," the trial court's determination that the testimony was reliable and admissible was reasonable. If a trial judge is nevertheless still reluctant to admit the testimony, the prosecutor may consider asking the court to compromise by giving a limiting instruction regarding how the expert’s opinion may be phrased, such as “to a reasonable degree of ballistic/technical/mechanical certainty.” Defense counsel can then challenge what that level of certainty means on cross-examination.
Authentication and Identity
Firearms evidence is subject to the same admissibility requirements as any other real evidence – that is, if the evidence is capable of being identified or authenticated as being what the proponent of the evidence says it is, then evidence of chain of custody is generally not required, and the items are admissible upon authentication or identification. See G.S. 8C-401-403; 901.
To be admissible, firearms evidence usually requires proof of identity of the weapon as being the weapon used in the crime. Such proof is generally obtained from the examination of the weapon’s particular characteristics, such as markings, serial numbers, or an officer’s initials. Evidence should also be presented that the weapon has not materially changed since it was recovered from the defendant or the crime scene. See State v. King, 311 N.C. 603 (1984) (pistol, rifle, bullet, and shell casings were admissible with identification at trial and testimony that items showed no material change in condition; note that in this case a detailed chain of custody was provided); State v. Oliver, 302 N.C. 28 (1980) (pistol and shells, along with other evidence, were properly admitted with positive identification of items; unchanged condition was inferred from the nature of the items, the positive identification, and the absence of evidence of any relevant change); State v. Hunt, 305 N.C. 238 (1982) (pistol admissible through testimony of witness that it was the same one sold to him by defendant shortly after the murder); State v. Dellinger, 308 N.C. 288 (1983) (identification was sufficient based on testimony by investigating officer that rifle bolt “appears to be the same one”).
A weapon may be admitted without showing a chain of custody if there is evidence tending to show that the weapon was used in the commission of a crime and found at the crime scene. State v. Moore, 301 N.C. 262 (1980) (chain of custody not required because pistol and bullet were sufficiently identified at trial and there was evidence that the weapon was used to commit the crime); State v. Brown, 280 N.C. 588 (1972) (unfired .22 caliber cartridge found at scene of rape and kidnapping five days after the crimes were committed was properly admitted because lapse in time affected the probative value of the evidence and not its competency; cartridge was identified by firearms expert as having been chambered in and then ejected from defendant’s rifle); but see State v. Harbison, 293 N.C. 474 (1977) (bullets removed from victim’s tires were properly excluded because of a lack of evidence of unchanged condition or identification of the bullets).
The trial judge has discretion to determine the standard of certainty required to show the identity and unchanged condition of all real evidence offered for admission at trial. See State v. Harbison, 293 N.C. 474 (1977). When firearms evidence is offered at trial for the purpose of proving that this defendant used this particular weapon to commit the charged crime, any lack of certainty in the identification of that weapon generally affects the weight given to the firearm identification testimony, rather than its admissibility. See State v. Reynolds, 307 N.C. 184 (1982) (although ballistics expert was unable to state whether bullets removed from victim’s body were definitely fired from defendant’s gun, due to poor condition of the gun, testimony that “they could have been” because nothing in their rifling characteristics were inconsistent with having been fired from that gun, plus testimony of many similarities between test bullets fired from gun and bullets from victim, was sufficient); State v. Ward, 300 N.C. 150 (1980) (ballistics expert was asked whether bullet removed from victim, which was too deformed for ballistics testing, “could have been fired from defendant’s pistol” – opinion properly admitted with response that “yes, it could have been fired from defendant’s pistol”).
Tool Mark Analysis – Other Than Firearms
In addition to the types of firearm analysis discussed above, “tool mark analysis” is also used to describe the examination of other physical objects for marks or irregularities caused by their manufacture or use, and the examination of cuts or scratches on wood, metal, and other hard surfaces. When tool marks are found at a crime scene, the North Carolina State Crime Laboratory can analyze the marks to find out what type of tool made the marks. The analyst can also determine whether a tool found on or connected to the defendant actually made the marks by examining “impressions” (marks that result when an object is crushed or compacted, such as when it is hit with a hammer) and “striations” (marks made when an object is pried or cut with a particular tool).
In performing these tests, the analyst may use a tool found at the crime scene or in the defendant’s possession, or use a “test tool” of the type that the defendant is suspected of using to commit a crime. The analyst will then compare the impressions or striations (using a microscope) to markings present on a piece of evidence submitted for examination. For example, marks visible on the ledge of a window that was pried open at the suspected point of entry in a burglary case can be compared to test marks made by the screwdriver/pliers/crowbar found in the defendant’s possession. See State v. Raines, 29 N.C. App. 303 (1976) (in prosecution for breaking and entering, larceny, and possession of burglary tools, trial judge did not err in allowing into evidence testimony of SBI agents to show, based on an analysis of paint on the door of the store broken into and paint on the crowbar found in the defendant’s vehicle, and by analysis of the markings left on the door, that the crowbar found in the defendants' car when they were arrested was the instrument used to break into the store); see also People v. Genrich, 928 P.2d 799 (Co. Ct. App. 1996) (citing Raines, and noting that “experts in the use and analysis of tools have long been permitted to testify concerning the marks left by […] different types of tools,” including knives, hammers, screwdrivers, and crowbars).