Comparison of the Columnar‐Thin‐Film and Vacuum‐Metal‐Deposition Techniques to Develop Sebaceous Fingermarks on Nonporous Substrates, |
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| Authors: | Stephanie F Williams MPS Drew P Pulsifer PhD Robert C Shaler PhD Robert S Ramotowski MS Shelly Brazelle MS Akhlesh Lakhtakia PhD DSc |
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| Institution: | 1. Forensic Science Program, Pennsylvania State University, University Park, PA;2. Materials Research Institute and Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA;3. Forensic Science Program and Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA;4. Forensic Services Division, United States Secret Service, Washington, DC |
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| Abstract: | Both the columnar‐thin‐film (CTF) and the vacuum‐metal‐deposition (VMD) techniques for visualizing sebaceous fingermarks require the deposition of a material thereon in a vacuum chamber. Despite that similarity, there are many differences between the two techniques. The film deposited with the CTF technique has a columnar morphology, but the film deposited with the VMD technique comprises discrete islands. A split‐print methodology on a variety of fingermarked substrates was used to determine that the CTF technique is superior for developing fingermarks on clear sandwich bags and partial bloody fingermarks on stainless steel. Both techniques are similar in their ability to develop fingermarks on glass but the CTF technique yields higher contrast. The VMD technique is superior for developing fingermarks on white grocery bags and the smooth side of Gloss Finish Scotch Multitask? tape. Neither technique worked well for fingermarks on black garbage bags. |
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| Keywords: | forensic science columnar thin film vacuum metal deposition morphology fingermark partial bloody fingermark |
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