gunpowder particles, when a bullet is fired through a weapon, it generates extreme heat. This heat and trace materials, such as lead and copper that make up the components of a bullet, are transferred to targets such as the bedsheet. A microscopic examination of the alleged “bullet hole” and test fired bullet holes was conducted. Sections of the alleged “bullet hole” and test fires were taken to the University of Oregon’s nano-tech facility for analysis. The University of Oregon operates a technical research facility that allows individuals to analyze materials on instrumentation not readily available to most facilities. In this case, the SEM-EDS was chosen as the most appropriate instrument. Scanning electron microscopy (SEM) is a surface analysis method widely used to determine the surface characteristics of sub-micron-sized particles. In the scanning electron microscope test, electron-sample interaction generates secondary electrons (SE), backscattered electrons (BSE), and characteristic X-rays. SE and BSE detectors capture these interactions to visualize the samples’ morphological and topographical information in the laboratory. BSE images are also used to rapidly discriminate the phases in multiphase samples. An Energy-dispersive X-ray Spectroscopy (EDS) detector within SEM is used in the testing labs to detect the characteristic X-rays and provide qualitative and quantitative elemental analysis of the sample. Photos A and B. Microscopic photographs of the alleged “bullet hole” in the bedsheet covering the body. Note the fibers surrounding the “bullet hole” are not altered. Photo C. Microscopic photograph of the same bedsheet test fires (positive control). Note the melted tips/bubbles of the bedsheet fibers caused by the heat transfer of the bullet passing through the bedsheet. The ends of each fiber on both the alledged “bullet hole” bedsheet and the test fired area were tested for trace elements found from the transfer of bullets through the fabric. The postive controls displayed copper (Cu) and lead (Pb) on the melted fibers along with expected trace levels of barium (Ba) and antimony (Sb) which are found as primer residue. The alledged “bullet hole” covering the body exhibited no evidence of a bullet passing through the bedsheet. Conclusion The assumed “bullet holes” in the bedsheet did not exhibit any melted fibers nor did they exhibit trace elements of a bullet passing through this fabric. The DA dismissed the murder charge. Toxicology continued from p. 47 PHOTO A PHOTO B 48 Trial Lawyer | Winter 2025
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