Shape Measurement Tools in Impression Evidence: A Statistical Approach
Mary Bush and Peter Bush, Laboratory for Forensic Odontology Research, School of Dental Medicine, State University of New York, Buffalo, New York and H. David Sheets, Department of Physics, Canisius College, Buffalo, New York.
In an earlier study, a shape analysis software was developed to examine principal causes of shape deformation in bitemarks. The goal of this project is to explore the feasibility of applying shape measurement tools to fingerprint evidence and footwear impressions. By expanding the software used in the quantitative analysis of bitemarks, principal shape variation in fingerprint and footwear impressions can be investigated, along with the repeatability and similarity of these types of pattern evidence. This will provide forensic practitioners with quantifiable validations of the quality of example items in pattern evidence.
Degradation in Chromosomal DNA Assessed Using PCR Amplification and Capillary Electrophoresis
Robert Allen and Emily Vandegrift, Department of Forensic Sciences, Oklahoma State University, Tulsa, Oklahoma and Byron Smith, Tulsa Police Department Crime Laboratory, Tulsa, Oklahoma.
DNA profiling methods are widely used in the forensic community. For highly degraded DNA samples, the number of methods is limited, and oftentimes requires the use of new, expensive instrumentation. This project investigates the use of quantitative template amplification technology (Q-TAT) assay to provide a comprehensive picture on the quantity and quality of DNA recovered from evidence. The overall goal is to research the ability of the multiplex polymerase chain reaction assay to provide data on the total human nuclear DNA (nDNA) present, the total male nDNA present, the total mitochondrial DNA (mtDNA) present, and information about the integrity of the DNA recovered, including the presence of PCR inhibitors, and if the nDNA or mtDNA is degraded.
Rapid Arson Sample Analysis Using DART Mass Spectrometry
John McClelland, Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa.
Gas chromatography/mass spectrometry (GC/MS) is the primary analytical method used in arson investigations. Yet, the technology is not ideal, requiring substantial time for sample analysis and data interpretation. Direct analysis in real time (DART) is a new ionization method for the rapid detection of analytes. DART mass spectrometry (MS) has the speed of a screening technique and the precision of GC/MS. This project investigates the use of DART MS to arson sample analysis. Project objectives include collecting DART-MS spectra of common fire-debris matrices burned with and without accelerants, and demonstrating the ability of DART-MS to successfully identify accelerants on burned materials.
Fast Gas Chromatography Capabilities in Drug Identification
Charles Cornett, Department of Chemistry/Engineering Physics, University of Wisconsin, Platteville, Wisconsin and Leah Macans, Wisconsin State Crime Laboratory, Milwaukee, Wisconsin.
Fast gas chromatography (GC) is a separation technique that couples the stable, rapid heating cycles of GC with narrower capillary columns and high phase ratio. The combination creates more theoretical plates per meter, and enables fast separations with potentially superior resolution and budget savings, especially if hydrogen is used in the mobile phase. While sample preparation time intervals limited the benefits of the Fast GC-H2 combination in ignitable liquid analysis in a previous study, no such limitations exist in drug analysis procedures and protocols. This project assesses the merit of the Fast GC-H2 combination in the identification of drugs. Specifically, this project assesses the expected gain in resolution and sample throughput, and investigates the feasibility of implementing and using the Fast GC-H2 combination in drug identification at the crime laboratory in light of hydrogen safety policies.
Application of Multivariate Statistical Procedures in Fire Debris Analysis: Investigating Matrix Interference Effects and Weathering of Ignitable Liquids on Association of Ignitable Liquid Residues to Neat Ignitable Liquids
Ruth Waddell Smith, School of Criminal Justice and Department of Chemistry, Michigan State University, East Lansing, Michigan and Victoria L. McGuffin, Department of Chemistry, Michigan State University, East Lansing, Michigan.
In arson investigations, fire debris is typically extracted and analyzed to determine the presence of ignitable liquid residues (ILRs). Yet, the identification of ILRs can be complicated by interference from substrates and weathering thereby making the association of ILRs to Neat Ignitable Liquids (NILs) very difficult. Previous research demonstrated the successful use of principal component analysis (PCA) and Pearson product moment correlation (PPMC) coefficients for the association and discrimination of ignitable liquids. This project investigates the effect of matrix interference and liquid weathering on ignitable liquid residue association to the Neat liquid. Besides applying multivariate statistical techniques, like PCA and PPMC, the use of a Soft Independent Modeling of Class Analogy (SIMCA) approach is investigated to classify an ILR to an ignitable liquid class with statistical confidence.