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Title: THE DEVELOPMENT OF A "GENETIC EYEWITNESS" PROFILING SYSTEM FOR LOW TEMPLATE FORENSIC SPECIMENS: IDENTIFICATION OF NOVEL PROTEIN, RNA, DNA BIOMARKERS.
Creator: Hanson, Erin, Ballantyne, Jack, University of Central Florida
Abstract / Description: In many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be...
Show moreIn many criminal investigations, valuable information regarding the physical appearance of suspected perpetrators or the time and order of events that transpired are provided by eyewitness accounts. However, the information obtained from eyewitnesses is often constrained by human recollection or subjective accounts and provides a biased description of the perpetrator's appearance or an inaccurate time line of events. Additionally, in numerous situations eyewitness accounts may not be available. An increasing reliance therefore is placed on the biological evidence recovered during criminal investigations to act as a silent witness, providing unbiased and scientific information that may aid in the resolution of criminal investigations. While the current capabilities of operational forensic crime laboratories include analytical methods to allow for a determination of the origin of a biological stain and for the recovery of a genetic profile of the donor, the sensitivity of such methods is not always sufficient to accommodate the limited amounts of biological material often recovered in forensic casework, Therefore, it is critical that continual advancements in the analysis of low template samples be made. In this report, we have sought to identify novel protein, RNA and DNA biomarkers that, in combination with enhanced profiling strategies, would allow for a determination of the time since deposition, the body fluid of origin and the genetic profile of the donor ("genetic eyewitness") of forensic low template specimens. First, we have developed a novel strategy for the determination of the time since deposition of dried bloodstains using spectrophotometric analysis of hemoglobin. An examination of the Soret band (lambda max = 414nm) in aged bloodstains has revealed a previously unidentified hypsochromic shift as the age of the stain increases. The extent of this shift permits a distinction to be made between stains that differ in age by only minutes, hours, days and months thus providing the highest resolution of any previously developed method. We also demonstrate that it may be possible to utilize a decline in enzyme activity to determine the age of a forensic biological stain. Second, we demonstrate that the differential expression of a panel of nine miRNAs allows for the identification of the body fluid origin of forensic biological stains using as little as 50pg of total RNA. This is the highest reported sensitivity of any RNA-based approach and this assay has demonstrated a high degree of specificity for each body fluid tested. The final task of this work was to identify novel DNA biomarkers and to develop enhanced profiling strategies to allow for greater sensitivity and reliability in the genetic profiling of low template samples. We demonstrate that the use of laser capture micro-dissection and enhanced amplification strategies resulted in the ability to obtain genetic profiles from as few as 2-5 epithelial cells and 5-10 sperm cells with greater reproducibility than previously reported studies. The use of a novel whole genome amplification method provided the ability to not only increase the quantity of genetic material obtained from micro-dissected cells but also the ability to recover additional genetic information from individual samples using novel DNA biomarkers. The novel biomarkers and profiling strategies described in this report provide the basis for the establishment of a molecular "genetic eyewitness" from low template forensic samples and demonstrate the future potential for routine and reliable analysis of trace amounts of genetic material recovered from low template biological evidence.
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Date Issued: 2008
Identifier: CFE0002373, ucf:47785
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002373

Title: ROOM TEMPERATURE FLUORESCENCE SPECTROSCOPY AS A TOOL FOR THE FORENSIC TRACE ANALYSIS OF TEXTILE FIBERS.
Creator: Rex, Matthew, Campiglia, Andres, University of Central Florida
Abstract / Description: ABSTRACT Trace textile fiber evidence is found at numerous crime scenes and plays an important role in linking a suspect to the respective scene. Several methods currently exist for the analysis of trace fiber evidence. Microscopy provides information regarding the fibers material, color and weave. For more detailed chemical analysis chromatographic methods are employed and for discrimination between dyes, liquid chromatography coupled with mass spectrometry (LC-MS) is currently the method...
Show moreABSTRACT Trace textile fiber evidence is found at numerous crime scenes and plays an important role in linking a suspect to the respective scene. Several methods currently exist for the analysis of trace fiber evidence. Microscopy provides information regarding the fibers material, color and weave. For more detailed chemical analysis chromatographic methods are employed and for discrimination between dyes, liquid chromatography coupled with mass spectrometry (LC-MS) is currently the method providing the most discrimination. These methods have primarily focused on the dyes used to color the fibers and have not investigated other components that can potentially discriminate among fibers. This dissertation deals with investigations into the fluorescence of the fiber dyes, (contaminants?) and the fibers themselves, as well as methodology for discriminating between fibers using fluorescence. Initial systematic analysis was conducted on dye standards and extracts taken from fibers colored with the respective dyes of interest. Absorbance, excitation and fluorescence spectra were compared between standards and extracts to determine the optimal area of the fiber to investigate: dyes, fluorescent impurities or the whole fiber. High performance liquid chromatography investigations were performed to give detailed information on the number of dye and fluorescent components present in extracts. Our investigations then focused on the best room-temperature fluorescence (RTF) data format for analysis and discrimination of fiber samples. An excitation emission matrix (EEM) was found to give the greatest amount of spectral information and provide the highest level of discrimination. Successful discrimination between non similar and similar fibers was achieved with the aid of Chemometric analysis. The level of discrimination obtained via RTF-EEM spectroscopy was sufficient to differentiate among fibers obtained from two separate cloths of the same material and colored with the same dye reagent. Final studies deal with examining exposure of the fiber to various environmental contaminants. Clothing fibers are typically exposed to myriad numbers of contaminants, from food stains to cigarette smoke. The challenge then becomes detecting fluorescence signals from trace amounts of these environmental contaminants. We demonstrate the detection and classification of polycyclic aromatic hyrdrocarbons (PAH) present on fibers after exposure to cigarette smoke. This dissertation also investigates the change in fluorescence emission after laundering fibers numerous times. The main drawback of chemical analysis of fibers is the destructive nature of the methods. To extract a dye or contaminant from a fiber essentially destroys the evidence. This leaves the investigator without their original sample in the courtroom. This also provides a finite amount of sample for testing and analysis. This is true of chromatographic methods and for the method detailed in this dissertation which makes use of extracts taken from fiber samples. Lastly, we propose an instrumental setup coupling a microscope to a spectrofluorimeter for the purpose of taking EEM directly from a fiber sample. This setup makes use of the superior optics of the microscope for focusing excitation light onto the fiber sample. Initial studies have been performed on extracts from a single textile fiber and EEM collected from said fiber.
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Date Issued: 2009
Identifier: CFE0002833, ucf:48084
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002833

Title: ANALYSIS OF MITOCHONDRIAL DNA CODING REGION SNPS BY PYROSEQUENCING.
Creator: Parker, Kyle, Ballantyne, Jack, University of Central Florida
Abstract / Description: To date, the use of mitochondrial DNA in forensic analysis has relied on the presence of variations in the control region to differentiate between samples. One problem that this analysis has shown is the occurrence of common Haplogroup H haplotypes or identical sequences. Thus, there is a need to enhance the distinguishing power of this type of analysis. One option has been to investigate the mitochondrial coding region for polymorphisms that could differentiate between samples with identical...
Show moreTo date, the use of mitochondrial DNA in forensic analysis has relied on the presence of variations in the control region to differentiate between samples. One problem that this analysis has shown is the occurrence of common Haplogroup H haplotypes or identical sequences. Thus, there is a need to enhance the distinguishing power of this type of analysis. One option has been to investigate the mitochondrial coding region for polymorphisms that could differentiate between samples with identical control region haplotypes. The goal of this study has been to identify polymorphic coding region sites for development in a Pyrosequencing assay that would effectively enhance the discriminatory power of mitochondrial DNA analysis. With this goal in mind, five duplexes have been successfully developed and tested, utilizing the ten polymorphic sites that had been selected, with most sites being specific to Caucasians. Validation studies were performed to test the durability of the assay. The specificity of the assay to primate and non-primate species was determined to be limited to primate species only. Sample variations, including mixtures, dilutions and environmental exposure, were utilized to assess the sensitivity of the Pyrosequencing method. It was found that a minimum initial DNA input of 10fg was necessary for reliable results. The Pyrosequencing assay was able to detect mixtures at a 1:1 ratio and environmental samples exposed to the elements from up to 1 week for blood and 6 weeks for semen. Samples designed to simulate typical casework materials were analyzed and found to provide for consistent results, including trace fingerprints and digested hair shafts. These validation results provide the conclusion that this assay is suitable for use in forensic casework and demonstrate that the mitochondrial coding region provides a viable alternative to hypervariable region analysis.
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Date Issued: 2007
Identifier: CFE0001562, ucf:47132
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001562

Title: URINALYSIS SCREENING OF DRUGS IN ADULTERATED SAMPLES VIA DIRECT ANALYSIS IN REAL TIME -- HIGH RESOLUTION/ MASS SPECTROMETRY (DART-HR/MS).
Creator: Olivieri, Bianca E, Bridge, Candice, University of Central Florida
Abstract / Description: Current screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace....
Show moreCurrent screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace. Therefore, a majority of individuals add commonly known products into the sample to evade detection by developing a false negative result. Although specimen integrity examinations are performed to identify tampering of the sample, these results are typically biased on the experience of the examiner. The purpose of this study was to develop an analytical screening technique that will detect the drug of interest as well as the presence of any additional products that may be added into the sample via Direct Analysis in Real Time � High Resolution/Mass Spectrometry (DART-HR/MS) which is an ambient ionization source that produces fast mass spectrum results that can provide semi-quantitative information of the target metabolite concentration. Although there are various studies that indicate the ability of the DART to detect drug compounds, there are no known studies that have examined how real-world urine samples are analyzed. Additionally, there are no current studies that take into consideration adulteration of the urine sample using the DART method. The results obtained in the study showed the ability for DART to identify molecular protonated peaks indicative of dextroamphetamine and/or the presence of masking agents. While the other target drugs could not be identified using this method, the identification of dextroamphetamine, adulterant products and the deuterated internal standard show promise in using this as a screening technique prior to confirmatory tests. Future work is currently being conducted to optimize the protocol for the evaluation of THC, cocaine and benzodiazepines.
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Date Issued: 2019
Identifier: CFH2000538, ucf:45623
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000538

Title: Quantitative Assessment of the effects of Microbial Degradation of a Simple Hydrocarbon Mixture.
Creator: Kindell, Jessica, Sigman, Michael, Bridge, Candice, Campiglia, Andres, University of Central Florida
Abstract / Description: Ignitable liquids consist of either a single organic compound or a complex organic mixture. In regards to fire debris analysis, the analyst is responsible for determining if an ignitable liquid residue is present. However, when extracted from soil-containing fire debris evidence, chemical degradation from microorganisms is observed to result in the loss of compounds based on chemical structure. It can also happen when the evidence container is stored at room temperature before analysis. This...
Show moreIgnitable liquids consist of either a single organic compound or a complex organic mixture. In regards to fire debris analysis, the analyst is responsible for determining if an ignitable liquid residue is present. However, when extracted from soil-containing fire debris evidence, chemical degradation from microorganisms is observed to result in the loss of compounds based on chemical structure. It can also happen when the evidence container is stored at room temperature before analysis. This can present a challenge to the fire debris analyst when identifying and classifying the ignitable liquid residue based on the criteria established by standard test methods. The purpose of this research was to observe the microbial degradation of fourteen compounds, at room temperature over a period of time, for possible by-product formation that could coincide with compounds normally present in an ignitable liquid. Additionally, a quantitative assessment was performed to observe and record the loss rate of compounds in a representative simple mixture. Finally, the loss rate from the simple mixture was compared to commercially available ignitable liquids. Degradation studies were conducted to observe the microbial degradation of a representative compounds (individually and in a simple mixture, both weathered and unweathered) and seven ignitable liquids of different ASTM E1618 classifications. Potting soil was spiked with 20 (&)#181;L of a liquid/compound and was allowed to stand at room temperature for a period of time. The simple mixture was evaporated to 50% and 90% using a steady nitrogen gas flow to compare the degradation process to the unweathered mixture. All samples were extracted and analyzed using passive-headspace concentration and gas chromatography-mass spectrometry.The formation of by-products was not observed when degrading the compounds from the simple mixture individually as seen in other research. The simple mixture, unweathered and 50% weathered, resulted in rapid degradation of their oxygenated compounds. The straight-chained alkanes and toluene were observed to be more susceptible to microbial attack than the highly-substituted aromatics and the branched and cyclic alkanes. The 90% weathered mixture followed the same degradation trend as the unweathered and 50% weathered samples, although it only contained two compounds. The loss rates/half-lives for each simple mixture sample (unweathered, 50% weathered, and 90% weathered) were determined to be approximately 3.5, 3.5, and 0.84 days. The unweathered and 50% weathered sample half-lives were similar due to containing compounds with similar susceptibility to degradation, while the 90% weathered sample contained one compound that was more highly susceptible to degradation. When comparing the 3.5 day half-life to the seven different ASTM class liquids, the isoparaffinic product and the naphthenic-paraffinic product had similar rates of degradation while aromatic solvent and normal alkane classes had the shortest half-lives. When observing the degradation of the gasoline, medium petroleum distillate and the miscellaneous, the constituent compounds were seen to exhibit a range of degradation rates that corresponded to half-lives less than and greater than 3.5 days.
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Date Issued: 2015
Identifier: CFE0005966, ucf:50817
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005966

Title: PHYSICAL CHARACTERISTICS OF AN INDIVIDUAL: THE IDENTIFICATION OF BIOMARKERS FOR BIOLOGICAL AGE DETERMINATION.
Creator: Alvarez, Michelle, Ballantyne, Jack, University of Central Florida
Abstract / Description: It is now a matter of routine for the forensic scientist to obtain the genetic profile of an individual from DNA recovered from a biological stain deposited at a crime scene. Potential contributors of the stain must either be known to investigators (i.e. a developed suspect) or the questioned profile must be searched against a database of DNA profiles such as those maintained in the CODIS National DNA database. However, in those instances where there is no developed suspect and no match is...
Show moreIt is now a matter of routine for the forensic scientist to obtain the genetic profile of an individual from DNA recovered from a biological stain deposited at a crime scene. Potential contributors of the stain must either be known to investigators (i.e. a developed suspect) or the questioned profile must be searched against a database of DNA profiles such as those maintained in the CODIS National DNA database. However, in those instances where there is no developed suspect and no match is obtained after interrogation of appropriate DNA databases, the DNA profile per se presently provides no meaningful information to investigators, with the notable exception of gender determination. In these situations it would be advantageous to the investigation, if additional probative information could be obtained from the biological stain. A useful biometric that could provide important probative information, and one that may be amenable to molecular genetic analysis, is the biological age of an individual. The ability to provide investigators with information as to whether a DNA donor is a newborn, infant, toddler, child, adolescent, adult, middle-aged or elderly individual could be useful in certain cases, particularly those involving young children such as kidnappings or in providing additional intelligence during terrorist investigations. Currently no validated molecular assays exist for age determination. Biological human ageing can be defined by two distinct processes, degenerative and developmental ageing. The degenerative process of ageing is based on theories which identify an increase or decrease in physiological conditions with increasing age. In contrast, the developmental process of ageing is based on the theory that as individuals increase in chronological age, there will be subtle corresponding molecular based biological changes, each requiring genes to be expressed or silenced, indicative of that particular stage of life. We investigated the degenerative process of chromosomal telomere shortening, as well as the developmental process of gene expression profiling analysis, in an attempt to identify biomarkers of biological age in a self-renewing tissue such as blood. While telomere length analysis was an ineffective method for age determination; gene expression analysis revealed three gene transcripts expressed in an age-dependent physiological manner. These species namely- COL1A2, HBE1 and IGFBP3, were found to be expressed at elevated levels in younger individuals, newborns, or post-pubertal individuals, respectively. The biological process of hemoglobin switching was also investigated for the possibility of determining human age. While experimenting with the potential of using the gamma-hemoglobin chains, as newborn specific gene candidates, we serendipitously discovered four novel truncated transcripts, which we have termed HBG1n1, HBG1n2, HBG2n2 and HBG2n3; whose expression was restricted to whole-blood newborn samples and specific fetal tissues. The molecular origin of these transcripts appears to be at the RNA level, being produced by specific rearrangement events occurring in the standard gamma hemoglobin transcripts (HBG1 and HBG2), which yield these new isoforms that are expressed in a highly regulated tissue specific manner.
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Date Issued: 2007
Identifier: CFE0001737, ucf:47297
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001737

Title: PERFORMANCE EFFICACY USING A COMPARISON OF COMMERCIAL AND IN-HOUSE Y-STR MULTIPLEX SYSTEMS FOR OPERATIONAL USE.
Creator: Mayntz-Press, Kathleen, Ballantyne, Jack, University of Central Florida
Abstract / Description: It is routine for the forensic scientist to obtain a genetic profile of an individual from DNA recovered from a biological stain deposited at a crime scene. In contrast, only a limited number of laboratories in the United States have the capability of performing Y-STR analysis in casework. In order to aid in facilitating the transfer of Y-STR technology to the crime laboratory community for operational use, a comparison between commercial products from three main vendors (Applied Biosystems...
Show moreIt is routine for the forensic scientist to obtain a genetic profile of an individual from DNA recovered from a biological stain deposited at a crime scene. In contrast, only a limited number of laboratories in the United States have the capability of performing Y-STR analysis in casework. In order to aid in facilitating the transfer of Y-STR technology to the crime laboratory community for operational use, a comparison between commercial products from three main vendors (Applied Biosystems AmpFℓSTR® Yfiler™ PCR Amplification Kit, Promega PowerPlex® – Y System, Reliagene Y-PLEX™ 12) and two in-house Y-STR multiplexes (MPI and MPB) commenced. The main intention for this comparison was to ascertain whether commercial Y-STR kits are able to obtain a male profile from difficult samples which have been accomplished with our in-house Y-STR multiplexes; such as mixtures, post coital specimens, and environmental insults. To aid the crime laboratory community an in depth comparison of the three main commercial Y-STR kits began in hopes to glean information in circumstances where Y chromosome polymorphisms may need to be employed. For example, the ability to provide investigators with the numbers of semen donors in multiple rape cases, identification of the genetic profile of the male component in a male/female mixture, and identification of the genetic profile of the male component in an extended interval post-coital sample. The capability of typing Y-STR loci by the crime laboratory community could dramatically affect the admissibility of Y-STR evidence. Therefore, the comparison of commercially available kits is an imperative process by which the scientific community acquires the necessary information to assess the ability of a procedure to obtain reliable results, determine the conditions under which such results can be obtained and define the limitations of the procedure. Thus the information for the study could lend itself to a standard being established amongst Y-STR kits for operational use and/or the production of a new Y-STR kit. One example of how the comparison of the three main commercial Y-STR kits could directly impact a new standard being established is by examining post-coital samples and their extreme limits (>48 hrs) for each kit in which a full male genetic profile was observed and comparing it to other commercial Y-STR kit and in-house Y-STR multiplexes. This would help establish the types of cases where specific Y-STR kits would be most useful, and the parameters in which each kit is able to perform. Thus leading to the development of a highly sensitive Y-STR kit that would be more sufficient to perform with the variety of samples an operational crime laboratory would routinely analyze. The capability of typing Y-STR loci by the crime laboratory community could dramatically affect the admissibility of Y-STR evidence. Therefore, the comparison of commercially available kits is an imperative process in order to inform the forensic community of different Y-STR kits available and their performance through direct comparison using modified SWGDAM validation guidelines.
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Date Issued: 2006
Identifier: CFE0001026, ucf:46824
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001026

Title: THE RELATIVE RECOVERABILITY OF DNA AND RNA PROFILES FROM FORENSICALLY RELEVANT BODY FLUID STAINS.
Creator: Parker, Charly, Ballantyne, Jack, University of Central Florida
Abstract / Description: Biological material (fluids or tissues) whether from the victim or suspect is often collected as forensic evidence, and methods to obtain and analyze the DNA found in that material have been well established. The type of body fluid (i.e. blood, saliva, semen, vaginal secretions, and menstrual blood) from which the DNA originated is also of interest, and messenger RNA typing provides a specific and sensitive means of body fluid identification. In order for mRNA profiling to be utilized in...
Show moreBiological material (fluids or tissues) whether from the victim or suspect is often collected as forensic evidence, and methods to obtain and analyze the DNA found in that material have been well established. The type of body fluid (i.e. blood, saliva, semen, vaginal secretions, and menstrual blood) from which the DNA originated is also of interest, and messenger RNA typing provides a specific and sensitive means of body fluid identification. In order for mRNA profiling to be utilized in routine forensic casework, RNA of sufficient quantity and quality must be obtained from biological fluid stains and the methods used for RNA analysis must be fully compatible with current DNA analysis methodologies. Several DNA/RNA co-extraction methods were evaluated based on the quantity and quality of DNA and RNA recovered and were also compared to standard non-co-extraction methods. The two most promising methods, the in-house developed NCFS co-extraction and the commercially available AllPrep DNA/RNA Mini kit, were then optimized by improving nucleic acid recovery and consistency of CE (capillary electrophoresis) detection results. The sensitivity of the two methods was also evaluated, and DNA and RNA profiles could be obtained for the lowest amount of blood (0.2 µL) and saliva and semen (1 µL) tested. Both extraction methods were found to be acceptable for use with forensic samples, and the ability to obtain full DNA profiles was not hindered by the co-extraction of RNA. It is generally believed that RNA is less stable than DNA which may prevent its use in forensic casework. However, the degradation rates of DNA and RNA in the same biological fluid stain have not been directly compared. To determine the relative stability of DNA and RNA, the optimized NCFS co-extraction protocol was used to isolate DNA and RNA from environmentally compromised stains. Dried blood, saliva, and semen stains and vaginal secretions swabs were incubated at set temperatures and outside for up to 1 year. Even at 56°C, DNA and RNA were both stable out to 1 year in the blood and semen stains, out to 3 months (DNA) and 1 year (RNA) in the saliva stains, and out to 6 months (DNA) and 3 months (RNA) in the vaginal secretions swabs. The recoverability of both nucleic acids was reduced when the samples were exposed to increased humidity, sunlight, and rain. In general, DNA and RNA stability was found to be similar with a loss in ability to obtain a DNA or RNA profile occurring at the same time point; however, there were instances where RNA body fluid markers were detected when a poor/no DNA profile was obtained, indicating that RNA in dried stains is sufficiently stable for mRNA body fluid typing to be used in forensic casework.
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Date Issued: 2011
Identifier: CFE0003596, ucf:48849
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003596

Title: Optimizing Laboratory Pyrolysis Methods to Compliment Real World Fire Debris.
Creator: Coulson, Richard, Sigman, Michael, Bridge, Candice, Yestrebsky, Cherie, Campiglia, Andres, University of Central Florida
Abstract / Description: Forensic analysts are tasked with determining the presence of ignitable liquid residue in fire debris. Analysis of fire debris allows the analyst to understand how the fire occurred. However, the presence of some substrates can potentially impact the identification of ignitable liquid residue and classification of a sample as positive or negative for the presence of ignitable liquid. Pyrolysis of building materials and furnishings (substrates) lead to background interference within the...
Show moreForensic analysts are tasked with determining the presence of ignitable liquid residue in fire debris. Analysis of fire debris allows the analyst to understand how the fire occurred. However, the presence of some substrates can potentially impact the identification of ignitable liquid residue and classification of a sample as positive or negative for the presence of ignitable liquid. Pyrolysis of building materials and furnishings (substrates) lead to background interference within the resulting chromatographic profile. To combat misclassification of a sample as positive for ignitable liquid residue, knowledge of the pyrolysis products from individual substrates is of utmost importance. However, unburned reference samples from a fire scene can be difficult to obtain. The use of a database in conjunction with the analysis of the samples can lead to a more complete analysis of fire debris. Within this research, four different burn methods (modified destruction distillation method, top heat, bottom heat, and tube furnace) were utilized in burning eight different flooring substrates (polyester, nylon, and olefin carpeting, carpet padding, vinyl flooring, laminate flooring, yellow pine, and plywood) to obtain pyrolysis/combustion product profiles. Each burn method was performed at three different burn times for a total of twelve different burns of each substrate. Standard methods, ASTM E1412-12 and ASTM E1618-14, were used in the extraction and interpretation of the laboratory burn products. Principal component analysis (PCA) was used to relate the laboratory burn results to neat ignitable liquid/substrate and large scale burn data sets.Laboratory burn data projected into the PCA space displayed that the laboratory burn data is similar to the data contained within the ILRC and Substrate databases. Differences observed within laboratory burn data projections illustrated the variability of the laboratory burn methods. The composition of the substrate dictated the pyrolysis/combustion products produced. While this research only focuses on flooring substrates, an increase in the number of different types of materials in the Substrate Database can aid analysts in identifying common pyrolysis/combustion products observed in fire debris.
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Date Issued: 2017
Identifier: CFE0006578, ucf:51357
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006578

Title: Selective Multivariate Applications in Forensic Science.
Creator: Rinke, Caitlin, Sigman, Michael, Campiglia, Andres, Yestrebsky, Cherie, Kuebler, Stephen, Richardson, Martin, University of Central Florida
Abstract / Description: A 2009 report published by the National Research Council addressed the need for improvements in the field of forensic science. In the report emphasis was placed on the need for more rigorous scientific analysis within many forensic science disciplines and for established limitations and determination of error rates from statistical analysis. This research focused on multivariate statistical techniques for the analysis of spectral data obtained for multiple forensic applications which include...
Show moreA 2009 report published by the National Research Council addressed the need for improvements in the field of forensic science. In the report emphasis was placed on the need for more rigorous scientific analysis within many forensic science disciplines and for established limitations and determination of error rates from statistical analysis. This research focused on multivariate statistical techniques for the analysis of spectral data obtained for multiple forensic applications which include samples from: automobile float glasses and paints, bones, metal transfers, ignitable liquids and fire debris, and organic compounds including explosives. The statistical techniques were used for two types of data analysis: classification and discrimination. Statistical methods including linear discriminant analysis and a novel soft classification method were used to provide classification of forensic samples based on a compiled library. The novel soft classification method combined three statistical steps: Principal Component Analysis (PCA), Target Factor Analysis (TFA), and Bayesian Decision Theory (BDT) to provide classification based on posterior probabilities of class membership. The posterior probabilities provide a statistical probability of classification which can aid a forensic analyst in reaching a conclusion. The second analytical approach applied nonparametric methods to provide the means for discrimination between samples. Nonparametric methods are performed as hypothesis test and do not assume normal distribution of the analytical figures of merit. The nonparametric permutation test was applied to forensic applications to determine the similarity between two samples and provide discrimination rates. Both the classification method and discrimination method were applied to data acquired from multiple instrumental methods. The instrumental methods included: Laser Induced-Breakdown Spectroscopy (LIBS), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS). Some of these instrumental methods are currently applied to forensic applications, such as GC-MS for the analysis of ignitable liquid and fire debris samples; while others provide new instrumental methods to areas within forensic science which currently lack instrumental analysis techniques, such as LIBS for the analysis of metal transfers. The combination of the instrumental techniques and multivariate statistical techniques is investigated in new approaches to forensic applications in this research to assist in improving the field of forensic science.
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Date Issued: 2012
Identifier: CFE0004628, ucf:49942
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004628

Title: Methodological Improvements in the mRNA Profiling Assays for Incorporation into DNA Casework Workflows.
Creator: Volk, Paris, Ballantyne, John, Gerasimova, Yulia, Baudelet, Matthieu, University of Central Florida
Abstract / Description: Currently, DNA profiling is the gold standard to identify an individual. However, determining body fluid origin is important in criminal investigations, offering additional information surrounding the circumstances of a crime. However, crime labs can only definitively identify blood and semen and presumptively saliva using techniques that consume time and sample and do not simultaneously identify all forensically relevant body fluids. This causes many crime labs to want to bypass body fluid...
Show moreCurrently, DNA profiling is the gold standard to identify an individual. However, determining body fluid origin is important in criminal investigations, offering additional information surrounding the circumstances of a crime. However, crime labs can only definitively identify blood and semen and presumptively saliva using techniques that consume time and sample and do not simultaneously identify all forensically relevant body fluids. This causes many crime labs to want to bypass body fluid identification altogether. Therefore, advances into more definitive molecular-based body fluid methods are necessary. One such technique is mRNA profiling because it provides a highly sensitive and specific approach to definitively identifying all relevant body fluids in parallel. Although advancements have been made, improvements to mRNA profiling methodologies still need to be researched such as 1) possible mRNA recovery from established DNA workflows and 2) possible integration of mRNA profiling into an upfront male DNA screening assay for triaging sexual-assault evidence likely to contain male DNA and reduce/eliminate a significant bottleneck in the standard DNA workflow of microscopic sperm identification. This study was designed to address these two issues by evaluating a novel way to recover RNA, for body fluid identification, from the waste fractions of a PrepFiler(TM) DNA extraction, and from the DNA extracts directly. Next, this study aimed to provide a relatively quick molecular-based approach for screening sexual-assault evidence. It involves extraction of RNA using the Dynabeads(TM) mRNA DIRECT(TM) Kit, while saving the extraction waste fractions for downstream male-DNA quantitation and STR profiling. The RNA is then used in a rapid and sensitive 1-step combined reverse transcription-HRM assay to positively detect the presence of sperm. Both non-conventional co-extraction methods successfully addressed current body fluid identification challenges and allowed for easy integration into existing workflows when single sourced, mixture and mock casework samples were analyzed.
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Date Issued: 2019
Identifier: CFE0007551, ucf:52627
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007551

Title: Chemometric Applications to a Complex Classification Problem: Forensic Fire Debris Analysis.
Creator: Waddell, Erin, Sigman, Michael, Belfield, Kevin, Campiglia, Andres, Yestrebsky, Cherie, Ni, Liqiang, University of Central Florida
Abstract / Description: Fire debris analysis currently relies on visual pattern recognition of the total ion chromatograms, extracted ion profiles, and target compound chromatograms to identify the presence of an ignitable liquid according to the ASTM International E1618-10 standard method. For large data sets, this methodology can be time consuming and is a subjective method, the accuracy of which is dependent upon the skill and experience of the analyst. This research aimed to develop an automated classification...
Show moreFire debris analysis currently relies on visual pattern recognition of the total ion chromatograms, extracted ion profiles, and target compound chromatograms to identify the presence of an ignitable liquid according to the ASTM International E1618-10 standard method. For large data sets, this methodology can be time consuming and is a subjective method, the accuracy of which is dependent upon the skill and experience of the analyst. This research aimed to develop an automated classification method for large data sets and investigated the use of the total ion spectrum (TIS). The TIS is calculated by taking an average mass spectrum across the entire chromatographic range and has been shown to contain sufficient information content for the identification of ignitable liquids. The TIS of ignitable liquids and substrates, defined as common building materials and household furnishings, were compiled into model data sets. Cross-validation (CV) and fire debris samples, obtained from laboratory-scale and large-scale burns, were used to test the models. An automated classification method was developed using computational software, written in-house, that considers a multi-step classification scheme to detect ignitable liquid residues in fire debris samples and assign these to the classes defined in ASTM E1618-10. Classifications were made using linear discriminant analysis, quadratic discriminant analysis (QDA), and soft independent modeling of class analogy (SIMCA). Overall, the highest correct classification rates were achieved using QDA for the first step of the scheme and SIMCA for the remaining steps. In the first step of the classification scheme, correct classification rates of 95.3% and 89.2% were obtained for the CV test set and fire debris samples, respectively. Correct classifications rates of 100% were achieved for both data sets in the majority of the remaining steps which used SIMCA for classification. In this research, the first statistically valid error rates for fire debris analysis have been developed through cross-validation of large data sets. The error rates reduce the subjectivity associated with the current methods and provide a level of confidence in sample classification that does not currently exist in forensic fire debris analysis.
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Date Issued: 2013
Identifier: CFE0004954, ucf:49586
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004954

Title: STATISTICAL ANALYSIS OF VISIBLE ABSORPTION SPECTRA AND MASS SPECTRA OBTAINED FROM DYED TEXTILE FIBERS.
Creator: White, Katie, Sigman, Michael, University of Central Florida
Abstract / Description: The National Academy of Sciences recently published a report which calls for improvements to the field of forensic science. Their report criticized many forensic disciplines for failure to establish rigorously-tested methods of comparison, and encouraged more research in these areas to establish limitations and assess error rates. This study applies chemometric and statistical methods to current and developing analytical techniques in fiber analysis. In addition to analysis of commercially...
Show moreThe National Academy of Sciences recently published a report which calls for improvements to the field of forensic science. Their report criticized many forensic disciplines for failure to establish rigorously-tested methods of comparison, and encouraged more research in these areas to establish limitations and assess error rates. This study applies chemometric and statistical methods to current and developing analytical techniques in fiber analysis. In addition to analysis of commercially available dyed textile fibers, two pairs of dyes are selected for custom fabric dyeing based on the similarities of their absorbance spectra and dye molecular structures. Visible absorption spectra for all fiber samples are collected using microspectrophotometry (MSP) and mass spectra are collected using electrospray ionization (ESI) mass spectrometry. Statistical calculations are performed using commercial software packages and software written in-house. Levels of Type I and Type II error are examined for fiber discrimination based on hypothesis testing of visible absorbance spectra profiles using a nonparametric permutation method. This work also explores evaluation of known and questioned fiber populations based on an assessment of statistical p-value distributions from questioned-known fiber comparisons with those of known fiber self-comparisons. Results from the hypothesis testing are compared with principal components analysis (PCA) and discriminant analysis (DA) of visible absorption spectra, as well as PCA and DA of ESI mass spectra. The sensitivity of a statistical approach will also be discussed in terms of how instrumental parameters and sampling methods may influence error rates.
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Date Issued: 2010
Identifier: CFE0003454, ucf:48396
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003454

Forensic Science (8)	+ -
forensic science (4)	+ -
multivariate statistics (3)	+ -
fire debris (2)	+ -
nonparametric statistics (2)	+ -

principal components analysis (PCA) (2)	+ -
Adulterants (1)	+ -
Age Determination (1)	+ -
Analytical Chemistry (1)	+ -
Biological Age (1)	+ -
Body Fluid Identification (1)	+ -
Body fluid identification (1)	+ -
Co-extraction (1)	+ -
Coding Region (1)	+ -
DART (1)	+ -
DNA Analysis (1)	+ -
DNA extraction (1)	+ -
DNA profiling (1)	+ -
DNA stability (1)	+ -
Drug Testing (1)	+ -
ELISA (1)	+ -
Fluorescence (1)	+ -
Forensic Biochemistry (1)	+ -
Gene Expression Profiling (1)	+ -
Hemoglobin (1)	+ -
High Resolution Melt (1)	+ -
Messenger RNA (1)	+ -
Mitochondrial DNA (1)	+ -
Multiplex (1)	+ -
Post-Coital (1)	+ -

ETD Collection (12)	+ -
Honors Collection (1)	+ -

University of Central Florida (13)	+ -
Ballantyne, Jack (5)	+ -
Campiglia, Andres (5)	+ -
Sigman, Michael (5)	+ -
Bridge, Candice (3)	+ -

Yestrebsky, Cherie (3)	+ -
Alvarez, Michelle (1)	+ -
Ballantyne, John (1)	+ -
Baudelet, Matthieu (1)	+ -
Belfield, Kevin (1)	+ -
Coulson, Richard (1)	+ -
Gerasimova, Yulia (1)	+ -
Hanson, Erin (1)	+ -
Kindell, Jessica (1)	+ -
Kuebler, Stephen (1)	+ -
Mayntz-Press, Kathleen (1)	+ -
Ni, Liqiang (1)	+ -
Olivieri, Bianca E (1)	+ -
Parker, Charly (1)	+ -
Parker, Kyle (1)	+ -
Rex, Matthew (1)	+ -
Richardson, Martin (1)	+ -
Rinke, Caitlin (1)	+ -
Volk, Paris (1)	+ -
Waddell, Erin (1)	+ -
White, Katie (1)	+ -

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