This piece describes how in response to gun crime, “A new machine, on loan from the Bureau of Alcohol, Tobacco and Firearms … scans spent bullet casings from crime scenes” and enters them into a national database. “Spent shells are loaded into the machine, and up comes 3-D scans of the unique scuffs and divots that every gun leaves behind… The scans are sent to technicians in Alabama who can match them up instantly to identical ones from another shooting—across county or state lines, to show they came from the same gun.”
The article inaccurately describes a claim that “every gun leaves” marks that are “unique” and that this is “just like your fingerprint.” And the article discusses a “unique ballistics imprint.”
No surprise, perhaps, that the article does not mention the presence or lack of research to support such claims about the technology and its reliability. The PCAST Report does speak to such firearms comparisons and the unfortunately lack of foundational research.