Blast Suppression Foam,Aqueous Gel Blocks,and their Effect on Subsequent Analysis of Forensic Evidence* |
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Authors: | Keith L Monson PhD Kelsey M Kyllonen MA Jeffrey L Leggitt MS Kelli E Edmiston MS Calvin R Justus PhD Mark F Kavlick PhD Maria Phillip BSChE Maria A Roberts MS Candie W Shegogue MS Gabriel D Watts BA |
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Institution: | 1. FBI Laboratory, Counterterrorism and Forensic Science Research Unit, 2501 Investigation Parkway, Quantico, VA, 22135;2. FBI Laboratory, Counterterrorism and Forensic Science Research Unit, Visiting Scientist Program, 2501 Investigation Parkway, Quantico, VA, 22135;3. FBI Laboratory, Evidence Response Team Unit, 2501 Investigation Parkway, Quantico, VA, 22135;4. FBI Laboratory, Latent Fingerprint Operations Unit, 2501 Investigation Parkway, Quantico, VA, 22135;5. FBI Laboratory, Latent Fingerprint Support Unit, 2501 Investigation Parkway, Quantico, VA, 22135;6. FBI Laboratory, Trace Evidence Unit, 2501 Investigation Parkway, Quantico, VA, 22135;7. FBI Laboratory, Questioned Documents Unit, 2501 Investigation Parkway, Quantico, VA, 22135 |
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Abstract: | In addition to having blast mitigation properties, aqueous foam concentrate AFC-380 blast suppression foam is designed to capture aerosolized chemical, biological, and radioactive particles during render-safe procedures of explosive devices. Exposure to aqueous environments and surfactants may negatively affect forensic evidence found at the scene, but the effects of AFC-380 foam and aqueous gel on the preservation and subsequent analysis of forensic evidence have not previously been investigated. Sebaceous finger and palm prints and DNA samples on paper, cardboard, tape, and various metal and plastic items, along with hairs, carpet and yarn fibers, and inks and documents, were exposed to AFC-380 foam. Similar mock evidence was also exposed to a superabsorbent gel of the type found in aqueous gel blocks used for shrapnel containment. Exposure to foam or aqueous gel was associated with a dilution effect for recovered DNA samples, but quality of the samples was not substantially affected. In contrast, exposure to AFC-380 foam or gel was detrimental to development of latent finger and palm prints on any substrate. Neither the hair nor the fiber samples were affected by exposure to either the foam or gel. Indented writing on the document samples was detrimentally affected by foam or gel exposure, but not inks and toners. The results from this study indicate that most types of forensic evidence recovered after being exposed to aqueous gel or blast suppression foam can be reliably analyzed, but latent finger and palm prints may be adversely affected. |
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Keywords: | forensic science blast suppression foam AFC-380 superabsorbent aqueous gel gel blocks radiological dispersal device (RDD) latent fingerprints DNA fiber analysis document analysis evidence recovery |
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