Advancing the Understanding of 3D Imaging for Firearms Identification

The use of 3D microscopes promises to strengthen the field of Firearms Identification.  The topographical profiles of fired bullets and cartridges can be compared and evaluated with the use of algorithms.  These comparisons will allow numerical values to be assigned to the similarity of these items for the first time in history.  But this technologically advanced tool has potential to assist in other ways.  Markings on evidence can be faint, obstructed by damage or manufacturing marks, or not easily made visible using a traditional comparison microscope due to lighting limitations.  These types of markings often result in examiners reporting inconclusive results.  This study will look closer at whether using a 3D microscope can allow for enhanced visualization of poor-quality markings and allow for more conclusive determinations of same source vs. different source.  With multiple manufacturers releasing microscopes capable of acquiring 3D images of bullets and/or cartridge cases, the data and images these instruments create will need to be interchangeable.  Forensic laboratories will individually decide what instruments they wish to purchase, but inter-lab comparisons may need to take place.  This study will test the compatibility of data generated by different vendors’ 3D microscopes.  Firearms examiners will look at images of fired bullets and cartridge cases created by different brands of 3D microscopes and determine if the quality and appearance of the images to perform accurate comparisons.