Overview
When there is reason to believe that asuspectmay have recently fired a gun, he or shecan begiven a“handwipe”or similartest, which is a type of gunshot primer residue test(oftenreferred to as a “GSR” test), to detect the presence of certain chemicals that are deposited on nearby surfaces when a gun is fired.For a moredetailedexplanation of how gunshot residue is created and how the handwipe test detects it, see, e.g.,Dr. Allison C. Murthalinxian Wu, “The Science Behind GSR: Separating Fact from Fiction,” Forensic Magazine, September 27, 2012.
In short, when a person pulls the trigger on a gun, this causes the firing pin to strike a “primer” located at the base of the cartridge. That primer strike, in turn, sparks a chemical reaction inside the cartridge that ignites the gunpowder, and the resulting explosion propels the bullet out of the barrel of the gun. The smoke and gas that comes out of the gun along with the bullet typically contains particles of unburnt gunpowder, tiny bits of metal, and signature chemicals from the primer mixture (usuallylead, antimony, and barium), which get fused together from the heat of the firing and settle on the person’s skin, clothing,and other nearby surfaces. The GSR test detects the presence (and quantity/amount) of these distinctive chemicals, which indicates that the person: (i) recently fired a firearm, (ii) was in very close proximity to the gun when it was fired, or (iii) came into direct physical contact with the person who did fire it (this isless common, and fewer particles will be detected).
There is no scientific test currently available to determine whether a particulargunhas been recently fired – the available testing only determines whether there is residue from a recent firing on the person’s skin, clothes, etc.It isalsoimportant to note that theabsenceof GSR does not prove thataperson didnotfire a gun, since theresidualchemicals can be removed by wiping, hand-washing, wind, rain, etc. SeeState v. Lambert, 341 N.C. 36 (1995) (“negative gunshot residue test could be explained by defendant's wringing of her hands and the use of her hands to wipe tears from her face”).
Reliabilityand Admissibility
Cases decided both before and after the 2011 amendments to Rule 702 adopting theDaubert standard have held that aproperly qualified witnessispermitted to testify about performing a GSR test, and give an opinion as to what the results of that test indicate(e.g., the likelihood that the defendant fired a gun, handled it shortly after it was fired, or was in close proximity at the time it was fired).See, e.g., State v. Thomas, __ N.C. App. __, 2021-NCCOA-700 (Dec. 21, 2021) (expert testimony properly admitted, collection and testing complied with SBI protocols); State v. Daughtridge, 248 N.C. App. 707 (2016)(post-Daubertamendment case, approving admissibility of expert opinion which relied in part on GSR test results);State v. Sparks, 297 N.C. 314 (1979)(forensic chemist was properly permitted to testify that tests performed on defendant’s trousers showed the presence of nitrites, and that nitrites were produced by burned gunpowder; chemist also properly was permitted to testify about gunshot residuefound on defendant’s left hand);Statev. Tilley, 292 N.C. 132 (1977)(properly qualified witness permitted to testify that defendant “probably”or “could have”fired a gun, based on results of test);State v. Crowder, 285 N.C. 42 (1974)(GSR test used in this case“demonstrably possesses the degree of reliability required to render it competent. We hold that evidence of theresults of thetestwas properly admitted”),vacated in parton other grounds,428 U.S. 903 (1976); see alsoState v. Barnes,345 N.C. 184 (1997)(“…the gunshot residue evidence tended to show that Barnes shot theTutterows. The evidence revealed that Barnes had fired a handgun or had handled a handgun soon after it was fired within a period close to the time of the killings”);State v. Benjamin, 83 N.C. App. 318 (1986).(expert permitted to testify thatpresence ofGSR on victim’s hands “could have” come from victim raisinghishands inadefensive posture, and absence of GSR on defendant’s hands “could have been caused” by passage of timeand defendant’s actions inbetween the shooting and the test).
The person whocollectsthe GSR wipe or sample does not have to be qualified as an expert–the state onlyneeds toshow that the person knew how to collect it properly and did so in this case.SeeState v. Crowder, 285 N.C. 42 (1974),vacated in parton other grounds,428 U.S. 903 (1976)(SBI agent was qualified to take gunshot wipefrom defendant’s hands when procedure was not “highly technical,” the agent’s background included technical police investigatory work, and agent was given personal instructions by chemist who was an expert with gunshot residue tests); seealsoState v. Oakes, 113 N.C. App. 332 (1994)(applyingsimilarrationale toanofficerwhoperformsa simplefield test onsuspecteddrugs).
Exigent Circ*mstances
A gunshot residue test is considered a nontestimonial identification procedure, similar to taking aphotograph or obtaininga voice sample, so whenever possible a nontestimonial order or other court order should be obtained before administeringthe test.SeeState v. Coplen, 138 N.C. App. 48 (2000)(like other procedures described inG.S. 15A-271, “a gunshot residue test is a relatively non-intrusive procedure” and it “falls within the broad language [of] ‘similar identification procedures’ in that it is comparable to handwriting exemplars, voice samples, photographs, and lineups”).
However, because a gunshot residue wipe must be taken within a few hours of the shooting to have any value, and because the residue can be easily removed or destroyed by normal activities such as hand-washing or reaching into a pocket, appellate courts have upheld the admissibility of GSR tests done in the absence of a court order based ona showing of exigent circ*mstances and probable cause.See, e.g.,State v. Page, 169 N.C. App. 127 (2005);State v. Coplen, 138 N.C. App. 48 (2000).
Admissibilityof Refusal?
At least onestate Supreme Courtcase has specifically held thatifadefendant refusestoconsent to aGSR test, the fact ofthatrefusalisadmissibleat trial asevidenceof guilt. See State v. Odom, 303 N.C. 163 (1981)(evidence of defendant’s refusal was properly admitted at trial:“In conclusion, we hold that the admission of testimony concerning defendant's refusal to submit to the gunshot residue test did not violate her constitutional right to counsel and did not deprive her of due process of law.”).
However, this holding appears to be in conflict with the general principle expressed in other cases which have held thatwhen a defendant exercises his or her rights by refusing to consent to a voluntary procedure, it is error to admit that refusal into evidence. See, e.g.,State v. Davis, 235 N.C. App. 424 (2014)(unpublished) (“North Carolina law bars the use of a defendant's exercise of his or her constitutional right to be free from an unreasonable search to imply guilt”);State v. Steele, 160 N.C. App. 710 (2003)(unpublished), citingState v. Jennings, 333 N.C. 579 (1993), cert denied,510 U.S. 1028 (1993)(“It is constitutional error to admit testimony as evidence of guilt that a defendant exercised his constitutional rights and refused to consent to a warrantless search.”).
