University Builds Forensic Library Of Plastics From 3D Printed Guns

    3D printed guns forensic library

    Image from Wikipedia.org

    As most are aware, the issue of 3D printed guns comes up from time to time, usually in a negative light.  Despite the controversy, scientists and enthusiasts have still provided useful designs and concepts that have taken 3D printed guns a long ways from from the first model in 2013.  With an expanded 3D printing industry, some went the extra mile to contemplate how this could affect criminal investigations in the future.  In 2017, a chemistry professor at the University of Mississippi, along with a graduate student began studying the physical evidence left behind from 3D printed guns.  Since then, they have amassed a reference library containing more than 50 types of polymers that can be used in forensic investigations.

    Ole Miss News reported on the University of Mississippi’s research team’s study, conducted by Professor James Cizdziel, Oscar Black, Robert Cody and David Edwards.  The following is an excerpt from the study and summarizes Phase 2, following the destruction of their Phase 1 test gun after one shot.

    In phase 2, we repeated the study using a 3D-printed 0.22 cal-
    iber firearm generated from ‘‘Washbear” blueprint files obtained
    online and printed using an Ultimaker 2+printer with accompany-
    ing CURA software. Firearm components were printed in PLA poly-
    mer, except the cylinders, which were interchangeable and
    consisted of four separate polymers: ABS, PLA, PETG, and CPE. For
    visual simplicity, the four polymers obtained consisted of different
    colors, with white, orange, green, and blue corresponding to ABS,
    PLA, PETG, and CPE respectively. The firing pin was machined from
    a 1/8″ steel drill bit blank using a dremel tool. Polymers were
    obtained from commercial providers: Ultimaker and MatterHackers.
    In both phases of the study GSR was collected from a cotton
    shirt situated ~0.3 m from the gun using a standard carbon-
    adhesive GSR stub (Ted Pella Inc.12.7 mm SEM pin stub). Spent car-
    tridges, bullets and GSR stubs were wrapped in aluminum foil and
    shipped to JEOL USA, Inc. for DART-MS analysis.
    I highly recommend checking out the study, “Identification of Polymers and Organic Gunshot Residue Evidence of 3D Printed Firearms Using DART-Mass Spectrometry: A Feasibility Study“, found HERE.  The study includes pictures of polymer stuck to bullets as well as expended casings that can be scraped and identified.
    What do you think about the ability to forensically identify polymers used in crimes?  Will this possibility lead to those considering homicide with a 3D printed firearm to line their barrel with metal instead?  Have any of you made your own 3D printed firearm yet, let us know your experience in the comments section.
    Doug E

    Doug has been a firearms enthusiast since age 16 after getting to shoot with a friend. Since then he’s taken many others out to the range for their first time. He is a husband, father, grandfather, police officer, outdoorsman, artist and a student of history. Doug has been a TFB reader from the start and is happy to be a contributor of content. Doug can be reached at battleshipgrey61 AT gmail DOT com.


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