When a firearm is used in a crime, bullets and fragments can be left at the scene. For investigators, this can be a source of potentially identifying evidence. But can police conclusively match a bullet to a particular firearm? Today, the tide is turning about how such evidence can be used in court.
What Is Forensic Ballistics?
When a bullet is fired from a firearm, the gun leaves microscopic marks on the bullet and cartridge case. If recovered from a crime scene, examiners can compare those bullets to bullets which are test-fired from a suspect’s gun. The marks left on the bullets can be analyzed to determine if it is likely the bullets at the crime scene were fired by a suspect’s firearm. In some cases, cartridge cases can also be compared this way.
According to the National Institute of Standards and Technology (NIST), the examiner can offer an expert opinion as to whether the bullet and gun match. However, NIST says the examiner cannot express the strength of the evidence in a numerical way.
Recent Maryland Decision on Ballistics
Maryland’s highest court recently decided a case regarding the admission of the opinion of an expert witness on ballistics identification. In sum, the court held that the examiner should not have been permitted to offer an unqualified opinion that crime scene bullets and a bullet fragment were fired from the defendant’s gun.
While the examiner could have testified that the defendant’s gun may have fired those bullets, the examiner could not testify that the bullets could have only been fired by the defendant’s gun. The examiner could have said the bullets either were consistent with or inconsistent with being fired by that particular firearm.
When reviewing the science behind ballistics identification, the court stated that the reports, studies, and testimony call into question the methodology used. Specifically, the methodology cannot reliably support an unqualified conclusion that bullets were fired from a particular firearm.
Use of Ballistics Evidence in New York Courts
In New York, the rules of evidence and caselaw currently allow a forensic examiner to testify a bullet was fired from a particular gun. However, defense attorneys have been successfully challenging this in recent years in individual cases.
For example, in a 2020 Bronx County case, the defense challenged the expert’s opinion. The argument was that the evidence did not satisfy the Frye standard (which applies to the admission of scientific evidence). Specifically, the defense argued that “a forensic comparison of the shell casings to test fires from the gun would lack ‘scientific validity and general acceptance in the relevant scientific community.’” The court ruled in their favor. In the court’s decision, the court held the examiner could only testify as to whether there were characteristics that would include or exclude the firearm at issue.
- Abruquah v. Maryland, Case No. C10-2022 (Md. June 20, 2023). Available at: https://mdcourts.gov/data/opinions/coa/2023/10a22.pdf (last accessed July 11, 2023).
- National Institute of Standards and Technology, Firearms and Toolmarks. Available at: https://www.nist.gov/firearms-and-toolmarks (last accessed July 11, 2023).
- People v. Ross, 68 Misc.3d 899 (Sup. Ct. Bronx County 2020) (Newbauer, J).
- Frye v. United States, 293 F. 1013 (D.C. Cir. 1923).
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