The reference cube: A new ballistic model to generate staining in firearm barrels

Area of Science:

• Forensic Science
• Ballistics
• Biomaterials

Background:

• Biological traces are found in firearm barrels after contact shots to the head.
• Current methods use silicone-coated, gelatin-filled boxes with a triple contrast method for staining simulation.
• There is a need for improved, transparent ballistic models for contact shot analysis.

Purpose of the Study:

• To develop a transparent ballistic model capable of simulating contact shots.
• To evaluate the effectiveness of different gelatin-based models in replicating firearm barrel staining.
• To compare the performance of the new model against existing methods.

Main Methods:

• Tested gelatin-filled polyethylene bottles (with/without silicone coating) and uncovered gelatin blocks.
• Developed a novel model using gelatin blocks covered with thin foil bags on a synthetic wipe.
• Performed contact shots using 9mm Luger and .38 special firearms, documenting staining via endoscopy and quantitative PCR analysis of barrel swabs.

Main Results:

• Reliable firearm barrel staining was achieved with the novel front-covered gelatin block model.
• Results were comparable to the previously used silicone-coated box model.
• The transparent nature of the new model allows for direct observation during testing.

Conclusions:

• The developed transparent ballistic model, specifically the front-covered gelatin block, is effective for simulating contact shots and firearm barrel staining.
• This model offers a viable and potentially superior alternative to existing methods.
• Further research should utilize symmetric forms, like cubes, for ballistic models simulating the human head.