The DNA technology applied to forensic science has improved significantly in recent years. As a result of these advancements, DNA profiles can be generated from a low-template amount of DNA. This advancement, however, can lead to more complex mixtures due to the instrumentation picking up trace amounts of DNA. This leads to the need for these more challenging profiles to be interpreted. Due to the lack of standardization in DNA profile interpretation, one complex DNA profile is likely to draw several different conclusions from DNA analysts when assessing the number of contributors (NoC). Probabilistic genotyping software (PGS) is a possible solution to the problems of complex DNA profile interpretations. DNA-View® Mixture Solution™, developed by Dr. Charles Brenner, is a continuous modelling PGS that considers genotypes, peak height, stutter, dropout, and other artifacts that result from stochastic effects in the interpretation of DNA profiles. Mixture Solution has the potential to minimize some of the uncertainty inherent in DNA analysis of profiles having multiple contributors. In this project, DNA mixture analysis with Mixture Solution was applied to two and three-person mixtures having ratios ranging from 1:1 to 8:1 and 1:1:1 to 8:1:8. Two scenarios with several hypotheses were tested regarding each contributor as if they were the person of interest (POI) in a real case. Mixture Solution assigns the most favorable hypothesis for and against the POI and calculates an LR representing the comparison of those two hypotheses. In the final reports, trends previously observed in two-person mixture ratios were also observed in three-person mixtures. The main factor driving low LR assignment in three-person mixtures is low template DNA. Low peak heights and dropout are the factors driving low LR assignment. The factors that make manual DNA profile interpretation challenging can also challenge PGS. However, the robustness of Mixture Solution was demonstrated throughout the project with complex three-person mixtures.

Throughout the past, bioarchaeologists have been concerned with identifying subsistence strategies of past populations and when subsistence strategies have transitioned from foraging to agriculture practices. Specifically, one area of major concentration has been examining the transition from foraging to agriculture in the southeast of the present day United States. The present study examines the transition of subsistence practices in prehistoric Tennessee utilizing dental microwear texture analysis. This study examined a total of 49 individuals from Archaic and Mississippian sites. These were compared temporally by comparing Archaic microwear signatures to Mississippian microwear signatures, and geographically, through the comparison of each site in relation to its geographic location. Non-parametric Mann-Whitney U tests were utilized to determine if statistical significant differences existed between the Archaic and Mississippian groups analyzed, and to determine if statistical significant differences existed based on geographic location. Due to the small sample size utilized in the study, it must be stated that the results are preliminary and further testing using dental microwear texture analysis needs to be undertaken in order to better understand the results.

The work of an international team of forensic experts led to the final determination that Salvador Allende, former Chilean president (1970-1973), committed suicide by firearm during the military coup against his socialist government on September 11, 1973. Included in the final report was the anthropologists’ skeletal trauma analysis documenting the gunshot trauma to the skull as consistent with the passage of a high velocity projectile under the chin and through the cranial cavity. The anthropological report was part of a multidisciplinary effort to finally address the questions surrounding the manner of Salvador Allende’s death, and to eliminate speculations that he was killed by the military. Although it is not the role of the anthropologist to determine manner of death in a forensic case, expertise in osteology and the biomechanics of high velocity projectile trauma to bone may contribute to the pathologist’s final conclusions about manner of death in firearm fatalities. Previous research looking at variation between homicides and suicides in firearm fatalities has used soft tissue trauma analysis and autopsy reports to identify common characteristics specific to these manners of death. They have found that anatomic location of entrance trauma, bullet direction, number of shots, and range of fire are important factors in understanding this variation. Anthropological research has not explored these differences as they are expressed on the skeleton, however; knowledge of variation in skeletal gunshot trauma, between self-inflicted and other-inflicted gunshot wounds, can better equip anthropologists to report pertinent information that can lead to accurate determinations of manner of death. The current study explores the factors of anatomic location of entrance trauma, bullet direction, and number of shots, with additional consideration to fracture severity and fracture patterns, in place of range of fire. The William M. Bass Donated Skeletal Collection and the Antioquia Modern Skeletal Reference Collection provided a total sample of 15 suicide and 19 homicide cases for this analysis. This research found that localized entry sites to the front and right sides of the head and to the chest were common in suicides. Entries to the left and front sides of the head and to the posterior side of the head and body were common in homicides. Further analysis of sequence of shots and entry sites revealed that the front of the head, common in both homicides and suicides, was more common in secondary gunshot wounds in homicides. Bullet directions common in suicides were right to left through the sagittal plane, and anterior to posterior through the coronal plane. The left to right direction through the sagittal plane was most common for homicides, whereas the anterior to posterior and posterior to anterior directions through the coronal plane were almost equally represented in homicides. Further analysis of sequence of shots and bullet direction revealed that the anterior to posterior direction was more common in secondary gunshot wounds in homicides. The transverse plane did not show statistically significant differences between homicides and suicides for either the inferior to superior or superior to inferior directions. For number of shots, homicides more commonly expressed multiple gunshot wounds and suicides more commonly expressed single gunshot wounds. Fracture severity analyses revealed that the presence of tertiary fractures (concentric fractures) in entrance wounds was more common in suicides. The presence of secondary fractures (radiating fractures) as the most severe fracture in entrance wounds was more common in homicides. These results suggest that fracture severity is higher in suicides, based on the amount of kinetic energy dispersed at impact, although it is unclear what factor influences these differences (range of fire, type of firearm, caliber of bullet, etc.). There was also a significant difference between homicides and suicides in fracture patterns for both entrance and exit wounds. These findings are based on a small sample and should be considered with caution, especially for use in a forensic setting. Further research is crucial to better understanding the variations seen in this study. Specifically, sequencing of shots should be further explored for its utility in distinguishing homicides and suicides as well as providing a better understanding of multi-shot cases. Additionally, more research should be conducted on fracture severity and fracture patterns with specific consideration to the factors that influence the variation seen between homicides and suicides.

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. 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.

Forensics face a complicated problem when evaluating intoxications induced by opioids and non – intoxications of opioid abusers since the in vitro concentrations of the said opioid overlap. Researchers found that acylcarnitines role as biomarkers for a diversity of diseases may also be used as biomarkers postmortem, easing the complications that occurs of evaluating the cause of death.  A reversed phase ultra high performance liquid chromatography (UHPLC) method in combination with mass spectrometer detection was developed for a quantitative analysis of different acylcarnitines in authentic blood samples. The hypothesis investigated was the altercation of acylcarnitine concentration depending on the cause of death, specifically when induced by opioids. Separation was achieved using ACQUITY UPLC HSS T3 1.8 µm (2.1 x 100 mm) Waters column along with a gradient elution consisting of Mobile phase A: 0.05% HFo in 10 mM Ammoniumformate and Mobile phase B: 0.05% HFo in Methanol. Flowrate was 0.4 mL/min. The method was validated in respect to linearity and range, accuracy, precision, LOD and LOQ as well as stability and degradation of acylcarnitines. Linearity was acceptable with R2 – values   for all the substances. Results from the authentic sample analysis showed no statistically significant difference between the investigated groups based on Kruskal – Wallis non-parametric tests and median comparison, however a trend in the data was found correlating to the investigated hypothesis suggesting it may be true.

No / The impregnation of items of clothing with drugs of abuse that are then smuggled through airports and ports of entry is a growing problem for law enforcement. This work describes the application of portable Raman spectroscopic techniques for the analysis of a range of natural and artificial fibre items of clothing impregnated with drugs of abuse. Textile pieces were soaked with the solutions of the drugs then left overnight to dry prior to spectroscopic examination. The feasibility of detection of the characteristic Raman spectral bands in the presence of background matrix signals is demonstrated, even for dyed clothing. Definitive evidence for contamination of the items of clothing concerned can be acquired within 20-25 s, without any form of sample pre-treatment or extraction being necessary. The feasibility of automatic spectral recognition of such illicit materials by Raman spectroscopy has been investigated by searching a database stored on the spectrometer computer and the use of principal component analysis. Copyright (c) 2014 John Wiley & Sons, Ltd.

Positive identification of a deceased individual is one of the major aspects of modem forensic death investigations. Incomplete or fragmented skeletal remains pose a problem for identification because the normal methods forensic anthropologists employ for compiling a biological profile of the decedent are of no use. Ancestry is an important aspect of the biological profile that, when known, can help narrow the focus of investigations by excluding many individuals from the search scope. This thesis describes molecular genetic methods which can be used to estimate ancestry in order to aid in forensic identification when other methods fail. The Y chromosome is one aspect of the genome shown to contain markers which are associated with the geographical origins of its possessor. The laboratory aspect of this research involved taking bone samples from humerii, extracting DNA from these samples and then sequencing a number of Y-SNPs in order to predict the biogeographical origins of each sample. Performing this research demonstrated the steps involved in this type of genetic ancestral analysis. At present, anthropology can only distinguish between major population groups. However, as research continues to be performed, the discriminatory power of molecular genetic ancestral analyses such as this has the potential to be further refined so that sub-populations may be distinguished between. This could be of great value if introduced into the forensic community.

The goal of this project was to reduce processing time for forensic DNA testing without incurring significant added costs and/or the need for new instrumentation, while still generating high quality profiles. This was accomplished by: 1) extraction normalization using the ChargeSwitch® Forensic DNA Purification Kit such that a small range of DNA concentrations was consistently obtained, eliminating the need for sample quantification and dilution; 2) developing fast PCR protocols for STR primer sets using shorter amplification methods, low volume reactions and non-fast thermal cyclers; and 3) developing a quicker 3130xl Genetic Analyzer detection method using an alternative polymer/array length combination. Extraction normalization was achieved through a reduction in bead quantity, thereby forcing an increase in bead binding efficiency. Four products (AmpliTaq Gold® Fast PCR Master Mix, KAPA2G™ Fast Multiplex PCR Kit, SpeedSTAR™ HS DNA Polymerase and Type-it Microsatellite PCR Kit) were evaluated for low volume (3μl) fast PCR on a 384-well Veriti® thermal cycler with the Identifiler primer set. KAPA2G™ was selected for 3μl fast PCR protocols using PowerPlex 16 HS and Identifiler Plus primer sets (42-51min), as well as 5μl and 6μl Identifiler fast reactions on a 9700 thermal cycler (51-60min). Alternative detection (POP-6™/22cm) achieved 24-28min run times, but with decreased resolution as compared to traditional POP-4®/36cm detection for alleles >200bp; however, 1bp resolution was still obtainable for alleles <300bp. These modifications resulted in robust databasing processes with up to a 37% reduction in processing time for buccal swabs and Buccal DNA Collectors™ using the three primer sets evaluated (3μl fast PCR reactions) and generated high quality STR profiles with ≥90% pass rates.

Condom trace evidence must not be overlooked in sexual assault cases; understanding the chemical and physical characteristics of condoms is imperative if condoms are to be useful evidence. Previous research shows that condom identification is possible, but it is equally important to evaluate durability of condom residues versus time. Using FT-IR, this study examined vaginal swabs from subjects who self-sampled at intervals for up to 72 hours after having intercourse with a condom. This study investigated whether age and the stage of the menstrual cycle affected the durability of residues in the vagina over time. This study revealed that condoms containing nonoxynol-9, silicone-based lubricants, and particulates provide valuable information for identification, and that nonoxynol-9 specifically withstands the vaginal environment for up to 72 hours. Additionally, age and menstrual cycle both appeared to have an effect on the durability of residues although larger sample size is desirable.

To further facilitate mitochondrial DNA (mtDNA) sequence analysis for human identity testing, a better understanding of its mutation rate is needed. Prior to the middle 1990's the mutation rate applied to a forensic or evolutionary analysis was determined by phylogenetic means, This method involved calculating genetic distances as determined by amino acid or DNA sequence variability within or between species. The mutation rate as determined by this method ranged from 0.025-0.26 nucleotide substitutions/ site/ myr (million years). With the recent advent of mtDNA analysis as a tool in human identity testing an increased number of observations have recently come to light calling into question the mutation rate derived from the phylogenetic method. The mutation rate as observed from forensic analysis appears to be much higher than that calculated phylogenetically. This is an area that needs to be resolved in human identity testing. Mutations that occur within a maternal lineage can lead to a possible false exclusion of an individual as belonging to that lineage. A greater understanding of the actual rate of mutation within a given maternal lineage can assist in determining criteria for including or excluding individuals as belonging to that lineage. The method used to assess the mutation rate in this study was to compare mtDNA sequences derived from the HVI and HVII regions of the D-loop from several different maternal lineages. The sequence information was derived from five unrelated families consisting of thirty-five individuals. One intergenerational mutational event was found. This derives to approximately 1.9 nucleotide substitutions/ site/ myr. This mutation rate was very consistent with several other similar studies. This increased mutation rate needs to be considered by forensic testing laboratories performing mtDNA sequence analysis prior to formulating any conclusive results.