Time is Money or Money is Time? A Rapid Operational Sequence for Detecting Fingermarks on Polymer Banknotes.

Banknotes are often found in high-profile crimes such as armed robberies, bribery, and terrorist activity. However, such exhibits present a challenge to forensic operatives regarding fingermarks development, due to their mass quantities, potential for fingermarks on both sides, and their unique complex background in terms of color, irregular patterns, and topography. Hence, the standard development protocols become inefficient, due to the difficulty in achieving high contrast images over the background. This study focused on finding an operational sequence that would minimize the time of work on polymer banknotes, in terms of both development and image processing. Thirty-two fingermarks were developed by vacuum metal deposition (VMD), black magnetic powder, and cyanoacrylate fuming (CA) followed by visualization and imaging by reflected short-wave UV (RUVIS) (96 in total), showing a distinct advantage to the CA and RUVIS imaging over the other two techniques with a 75% success rate in the dark and high background regions, due to its physical principle which neutralizes high background interference. The images were then scanned by the automatic fingerprint identification system (AFIS) to test its ability to correctly differentiate false background features from real ones, again, showing a superiority of the RUVIS with 63% of the total initial marked features, being real. Overall, the CA and RUVIS sequence was found to be an ultimate method for multiple, same-type surfaces, with the RUVIS capable of visualization and capturing of the images simultaneously, significantly reducing the time of development and image processing.

Blood or not blood-That is the question. A non-destructive method for the detection of blood-contaminated fingermarks.

Working in crime scenes presents a challenge to the forensic scientist, as some surfaces, such as floors and walls, cannot be transferred to the lab for further development and must, therefore, be processed at the crime scene itself. Two main types of latent fingermarks may be encountered in crime scenes: amino acids based and blood contaminated. One of the most common reagents, which are able to develop both types of fingermarks on porous surfaces, is ninhydrin. As blood contaminated fingermarks may be crucial in connecting the suspect to the crime it is important to be able to distinguish between them and natural fingermarks. More than a decade of experience in crime scene investigations led to the understanding that there is a clear visual distinction between natural and blood contaminated fingermarks that are developed by ninhydrin. This study attempted to translate the visual difference into a mobile, non-destructive spectrophotometric method that can be used in crime scenes. Three independent spectrophotometric approaches were examined. The first showed a clear difference between the UV-vis spectra of the solution of blood and ninhydrin versus that of Ruhemann's purple. The second introduced another method in the solid phase to better simulate a real exhibit found in crime scenes. Once establishing the scientific foundation for the visible difference, a third technique for colour measurements was used in order to provide a potentially fast, quantitative, accurate and non-destructive field test for blood determination at the crime scene.

Morphological, spectral and chromatography analysis and forensic comparison of PET fibers.

Poly(ethylene terephthalate) (PET) fiber analysis and comparison by spectral and polymer molecular weight determination was investigated. Plain fibers of PET, a common textile fiber and plastic material was chosen for this study. The fibers were analyzed for morphological (SEM and AFM), spectral (IR and NMR), thermal (DSC) and molecular weight (MS and GPC) differences. Molecular analysis of PET fibers by Gel Permeation Chromatography (GPC) allowed the comparison of fibers that could not be otherwise distinguished with high confidence. Plain PET fibers were dissolved in hexafluoroisopropanol (HFIP) and analyzed by GPC using hexafluoroisopropanol:chloroform 2:98 v/v as eluent. 14 PET fiber samples, collected from various commercial producers, were analyzed for polymer molecular weight by GPC. Distinct differences in the molecular weight of the different fiber samples were found which may have potential use in forensic fiber comparison. PET fibers with average molecular weights between about 20,000 and 70,000 g mol(-1) were determined using fiber concentrations in HFIP as low as 1 µg mL(-1). This GPC analytical method can be applied for exclusively distinguish between PET fibers using 1 µg of fiber. This method can be extended to forensic comparison of other synthetic fibers such as polyamides and acrylics.

ApoSense: a novel technology for functional molecular imaging of cell death in models of acute renal tubular necrosis.

PURPOSE: Acute renal tubular necrosis (ATN), a common cause of acute renal failure, is a dynamic, rapidly evolving clinical condition associated with apoptotic and necrotic tubular cell death. Its early identification is critical, but current detection methods relying upon clinical assessment, such as kidney biopsy and functional assays, are insufficient. We have developed a family of small molecule compounds, ApoSense, that is capable, upon systemic administration, of selectively targeting and accumulating within apoptotic/necrotic cells and is suitable for attachment of different markers for clinical imaging. The purpose of this study was to test the applicability of these molecules as a diagnostic imaging agent for the detection of renal tubular cell injury following renal ischemia. METHODS: Using both fluorescent and radiolabeled derivatives of one of the ApoSense compounds, didansyl cystine, we evaluated cell death in three experimental, clinically relevant animal models of ATN: renal ischemia/reperfusion, radiocontrast-induced distal tubular necrosis, and cecal ligature and perforation-induced sepsis. RESULTS: ApoSense showed high sensitivity and specificity in targeting injured renal tubular epithelial cells in vivo in all three models used. Uptake of ApoSense in the ischemic kidney was higher than in the non-ischemic one, and the specificity of ApoSense targeting was demonstrated by its localization to regions of apoptotic/necrotic cell death, detected morphologically and by TUNEL staining. CONCLUSION: ApoSense technology should have significant clinical utility for real-time, noninvasive detection of renal parenchymal damage of various types and evaluation of its distribution and magnitude; it may facilitate the assessment of efficacy of therapeutic interventions in a broad spectrum of disease states.