This study investigated the discrimination between sources of the semi-precious mineral, nephrite, by a targeted microanalytical determination of the elemental composition, including the trace elements. Nephrite specimens were collected from two significant nephrite sources in New Zealand, namely the Westland and Wakatipu fields, and combined with donated specimens from the Southland field to complete a representative collection of New Zealand nephrite. A small number of nephrite specimens were donated from the South Westland nephrite field and from foreign sources. Representative fragments of these specimens were analysed by electron microprobe analysis (EMPA) for major elements and by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace elements. The data obtained by the analytical procedure were treated within a compositional data (CoDa) framework of statistical analysis that focuses on the relative sizes of the components in the data set. The data were transformed under the guidelines of the CoDa framework, where appropriate, and the transformed data were treated with standard statistical methods for exploratory data analysis, dimension reduction and discriminant analysis. Advances were made to the Hotelling’s method for comparison of multivariate means by incorporating a permutation evaluation step. This permutation method removes the requirement for multivariate normality, and it also allows comparisons to be made when there are many more variables than observations, as is often the case when objects are being characterized using elemental data. The strategy used in this study showed that it is possible to discriminate between sources of nephrite at both an intra- and inter-source level within New Zealand. In addition, an exploratory investigation showed that New Zealand nephrite could be differentiated from the few nephrite specimens from foreign sources that were available for comparison. Recommendations are made for the protection of the New Zealand nephrite resource and for casework, based on the results obtained in this study.

This study investigated the discrimination between sources of the semi-precious mineral, nephrite, by a targeted microanalytical determination of the elemental composition, including the trace elements. Nephrite specimens were collected from two significant nephrite sources in New Zealand, namely the Westland and Wakatipu fields, and combined with donated specimens from the Southland field to complete a representative collection of New Zealand nephrite. A small number of nephrite specimens were donated from the South Westland nephrite field and from foreign sources. Representative fragments of these specimens were analysed by electron microprobe analysis (EMPA) for major elements and by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace elements. The data obtained by the analytical procedure were treated within a compositional data (CoDa) framework of statistical analysis that focuses on the relative sizes of the components in the data set. The data were transformed under the guidelines of the CoDa framework, where appropriate, and the transformed data were treated with standard statistical methods for exploratory data analysis, dimension reduction and discriminant analysis. Advances were made to the Hotelling’s method for comparison of multivariate means by incorporating a permutation evaluation step. This permutation method removes the requirement for multivariate normality, and it also allows comparisons to be made when there are many more variables than observations, as is often the case when objects are being characterized using elemental data. The strategy used in this study showed that it is possible to discriminate between sources of nephrite at both an intra- and inter-source level within New Zealand. In addition, an exploratory investigation showed that New Zealand nephrite could be differentiated from the few nephrite specimens from foreign sources that were available for comparison. Recommendations are made for the protection of the New Zealand nephrite resource and for casework, based on the results obtained in this study.

This study investigated the discrimination between sources of the semi-precious mineral, nephrite, by a targeted microanalytical determination of the elemental composition, including the trace elements. Nephrite specimens were collected from two significant nephrite sources in New Zealand, namely the Westland and Wakatipu fields, and combined with donated specimens from the Southland field to complete a representative collection of New Zealand nephrite. A small number of nephrite specimens were donated from the South Westland nephrite field and from foreign sources. Representative fragments of these specimens were analysed by electron microprobe analysis (EMPA) for major elements and by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace elements. The data obtained by the analytical procedure were treated within a compositional data (CoDa) framework of statistical analysis that focuses on the relative sizes of the components in the data set. The data were transformed under the guidelines of the CoDa framework, where appropriate, and the transformed data were treated with standard statistical methods for exploratory data analysis, dimension reduction and discriminant analysis. Advances were made to the Hotelling’s method for comparison of multivariate means by incorporating a permutation evaluation step. This permutation method removes the requirement for multivariate normality, and it also allows comparisons to be made when there are many more variables than observations, as is often the case when objects are being characterized using elemental data. The strategy used in this study showed that it is possible to discriminate between sources of nephrite at both an intra- and inter-source level within New Zealand. In addition, an exploratory investigation showed that New Zealand nephrite could be differentiated from the few nephrite specimens from foreign sources that were available for comparison. Recommendations are made for the protection of the New Zealand nephrite resource and for casework, based on the results obtained in this study.

This study investigated the discrimination between sources of the semi-precious mineral, nephrite, by a targeted microanalytical determination of the elemental composition, including the trace elements. Nephrite specimens were collected from two significant nephrite sources in New Zealand, namely the Westland and Wakatipu fields, and combined with donated specimens from the Southland field to complete a representative collection of New Zealand nephrite. A small number of nephrite specimens were donated from the South Westland nephrite field and from foreign sources. Representative fragments of these specimens were analysed by electron microprobe analysis (EMPA) for major elements and by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace elements. The data obtained by the analytical procedure were treated within a compositional data (CoDa) framework of statistical analysis that focuses on the relative sizes of the components in the data set. The data were transformed under the guidelines of the CoDa framework, where appropriate, and the transformed data were treated with standard statistical methods for exploratory data analysis, dimension reduction and discriminant analysis. Advances were made to the Hotelling’s method for comparison of multivariate means by incorporating a permutation evaluation step. This permutation method removes the requirement for multivariate normality, and it also allows comparisons to be made when there are many more variables than observations, as is often the case when objects are being characterized using elemental data. The strategy used in this study showed that it is possible to discriminate between sources of nephrite at both an intra- and inter-source level within New Zealand. In addition, an exploratory investigation showed that New Zealand nephrite could be differentiated from the few nephrite specimens from foreign sources that were available for comparison. Recommendations are made for the protection of the New Zealand nephrite resource and for casework, based on the results obtained in this study.

Age-at-death estimation is a key component of creating a biological profile in forensic and bioarchaeological contexts, and the development of methods that utilize different skeletal elements or observe traits in a new manner are an important part of progress in the study of forensic anthropology. Use of the acetabulum for identifying age-at-death is among new methods being developed, and the recently published method by Calce (2012) was the focus of the present study. The present author analyzed a sample of 489 modern American individuals drawn from the William M. Bass Donated Skeletal Collection housed at the University of Tennessee and assigned each individual to a phase described by Calce (2012). The results of the present study show that use of this method correctly classified age-at-death 62.2% of the time. The performance of this method is low compared to the results of the initial study where Calce (2012) found the method to be 81% accurate. This suggests that the acetabulum is not as beneficial as an age-at-death indicator as previously considered, and that more research on the utility of the acetabulum as an age indicator is required.

The awareness of health risks associated with sun exposure, primarily ultra violet (UV) radiation, have played a large role in the introduction of sunless self-tanning products. These products, produced by cosmetic companies, are intended to provide the user with a sun-tanned appearance without exposing the skin to harmful UV radiation. While the manufacturers of these products claim that the products are transfer-free, several reports of the tanner depositing onto the wearers clothing have been documented1. As this is a highly undesirable characteristic for the consumer, the product's ability to transfer onto clothing makes sunless self-tanners a potentially valuable piece of forensic evidence in cases where an altercation between two individuals has occurred, specifically in sexual assaults, beatings, and homicides. The presence of self-tanner on an individual's clothing could help corroborate a story and provide an additional piece of evidence and/or leads to an investigation. The purpose of this study was to determine if sunless self-tanners transfer from skin to clothing. Given that a transfer occurs, this research was also intended to both identify and evaluate the differences seen between self-tanning products using instrumental techniques that would typically be used in forensic labs. Sixteen sunless self-tanning products were added to the skin as directed by the manufacturer. After an assigned time interval since application (15 minutes, 30 minutes, 1 hour, 3 hours, 6 hours, or 12 hours) was reached, a white cotton swatch was used to wipe a portion of the sunless self-tanner off of the skin in attempt to simulate a realistic scenario of an altercation between individuals who may be wearing the product. Observations of the cotton swatches were document. Transferred material on the cotton swatches was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Analysis of the products prepared directly from the packaging as well as two samples containing transferred material were analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). All of the sixteen samples tested transferred from the skin onto the cotton swatch when forcibly wiped at each time interval. FTIR analysis was unable to discriminate between the commercial products but was able to separate the samples into six groups based on similarities seen between the spectra. Analysis using this instrumental technique was useful in identifying the samples as sunless self-tanning products, but was unable to differentiate further. Analysis of the sunless self-tanners prepared directly from their packaging/bottle using GC-MS was able to differentiate between the products, providing a combination of chemical ingredients that were unique to each product. Analysis of the transferred material on the cotton swatches did not identify all of the chemical components that were earlier considered unique to that sample, however, peaks were observed in the chromatogram that were also present in the samples when prepared directly from their packaging. These transferred samples were able to be identified when a known sample was available for comparison. The instrumental techniques used in this study are useful in analyzing and identifying suspected sunless self-tanner stains on clothing in a crime laboratory setting. The results obtained from this analysis can provide probative information in an investigation.

Thesis (M.S.F.S.) / There is need for further development of cellular collection techniques in the field of forensic science. Currently, forensic analysts are limited to the use of swabs, taping, cutting, and scraping methods to collect cellular material. Each of these methods has its own benefits and drawbacks, however, none of them result in 100% recovery of the cells. The Microbial Vacuum system (M-Vac®), developed by MSI, is a liquid based cellular collection system that was originally developed to collect microbes in the food-processing industry from various surfaces. This research represents a detailed study into the feasibility of utilizing the M-Vac® system for forensic purposes. Specifically, the phosphate buffer used with the M-Vac® was tested to confirm that it does not have a detrimental effect on cellular retrieval. Further, the ability of the M-Vac® to collect cellular material from a variety of substrates was tested. It was determined the M-Vac® can successfully collect both blood and semen from tile, denim, carpet, and brick materials in sufficient quantity for downstream PCR analysis. Additionally, examination into whether DNA was dispersed during collection due to the significant force of impact of the liquid striking the surface was conducted. Specifically, areas surrounding the sample collection region were swabbed after collection with the M-Vac® and tested. Quantitative PCR analysis showed that DNA was retrieved up to 4 inches away from the collection area. This indicates that the M-Vac® system is a viable cell collection technique for forensic purposes, but only for samples which are isolated (i.e. where there is not another probative sample adjacent to it). If there are two probative samples within the same vicinity, then swabbing or taping is the recommended method of collection.

In forensic contexts, eliminating the ability for identification and/or discovery of victims is a priority for many individuals perpetrating a homicide. This can be achieved in a number of ways, but a common belief is that acidic products can accomplish both. The current study submerged twelve complete pig (Sus scrofa) heads in three different commercial products containing hydrochloric or sulfuric acid (n=4 for each product) in order to determine if complete liquefaction was possible. The product with 31.45% concentration of hydrochloric acid was able to liquefy each head in five days. Motor vehicle battery acid (37% concentration of sulfuric acid) was able to liquefy each head in five weeks. The product with the low concentration (5 – 10%) of hydrochloric acid was not able to remove the soft tissue, but did affect the structure and consistency of the bones and teeth. Some common chemicals therefore are effective tools in body disposal.

Modern DNA analysis is possible due to the discovery of repeating microsatellite regions in DNA and successful implementation of the polymerase chain reaction (PCR) in laboratories. PCR amplification chemistries that contain short tandem repeat (STR) loci are sensitive. As a result, the discrimination power within human identification sciences has increased in recent years. Despite these advances, cellular admixtures are commonly collected, and the resultant “DNA mixture profile” is difficult to interpret as it is often encumbered by low-signals and allele drop-out. Regularly detected PCR artifacts can further complicate interpretation. One commonly encountered artifact is stutter, the result of strand slippage during PCR. Stutter can be of two types: forward and reverse. Reverse stutter (or back stutter) is the most prevalent and is one repeat unit shorter (n - 1) than the template strand. In contrast, forward stutter is one repeat unit longer (n + 1). If a reverse stutter amplicon is produced there is the distinct possibility that a stutter product of stutter may occur. This artifact is usually referred to as double-back stutter (DBS) or n - 2 stutter. Recently there has been renewed interest in examining signal approaching baseline levels. As the sensitivity of the process improves, so does the probability of detecting DBS. Therefore, studies that examine the peak height distributions, rarity, stutter signal-to-noise distances and the general impact of DBS on the signal are warranted. Models simulating PCR, and the entire forensic DNA process, have been created by this laboratory. The work presented herein builds upon a preexisting model; specifically, the dynamic model was extended such that DNA profiles consisting of 21 autosomal STRs, consistent with the GlobalFilerTM multiplex, are simulated. Furthermore, this expansion incorporated a three-type Galton-Watson branching process allowing DBS to be added to the simulated electropherogram (EPG). The in silico model was used to simulate the amplification of a 1:43 and 1:73 mixture at a total DNA concentration of 0.3 and 0.5 ng, respectively. We chose these extreme mixture ratios because the signal from these minor contributors would be most susceptible to DBS effects from the major contributor. A total of 1200 alleles from each contributor were simulated at each target, and effects of DBS on the signal from the minor contributor were characterized. At 0.3 and 0.5 ng both the noise and stutter signal histograms are right-skewed and a Kolmogorov-Smirnov (KS) test indicates that the noise and DBS were significantly different (p-value < 4x10-6). The average peak height of DBS for all loci in both scenarios were less than 50 RFU (Relative Fluorescence Units), and the DBS ratios ranged from 0.29 to 2.15% of the main allele, with the median ratios less than 0.5%. A per locus analytical threshold (AT) was calculated for both the 0.3 and 0.5 ng targets using two k-values: 3 and 4. The k-value is chosen based on the Type I risk assessment, wherein increasing the k-value increases AT. The percentage of DBS peaks greater than AT when k = 3 for the mixtures amplified at 0.3 and 0.5 ng ranged from 0 to 7.08% and 0 to 10.50%, respectively. Interestingly, when k = 4 the percentage of DBS peaks greater than AT for 0.3 and 0.5 ng reduced to 0 to 1.08% and 0 to 0.17%, respectively. This suggests that modeling DBS in continuous systems may not be necessary if the laboratory continues to rely on a system that requires an AT of sufficient strength. However, with the advent of Bayesian or machine learning-based approaches to analyzing EPGs, thus removing AT in its entirety, a complete understanding of the prevalence of DBS is necessary. This work shows that DBS from an extreme major using our laboratory protocols is not likely to be in the same signal regime as the signal from alleles; however, it does show that signal from DBS is significantly different from noise. Therefore, the software expert pair should be carefully considered during the validation stage and laboratories should consider DBS during interpretation, especially if enhanced post-PCR parameters are implemented into the forensic laboratory process.

Benzodiazepines are among the most prescribed compounds for anti-anxiety and are present in many toxicological screens. These drugs are also prominent in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to their potency, a low dose of these compounds is often administered to victims; therefore, the target detection limit for these compounds in biological samples is 10 ng/mL. Currently these compounds are predominantly analyzed using immunoassay techniques; however more specific screening methods are needed. The goal of this dissertation was to develop a rapid, specific screening technique for benzodiazepines in urine samples utilizing surface-enhanced Raman spectroscopy (SERS), which has previously been shown be capable of to detect trace quantities of pharmaceutical compounds in aqueous solutions. Surface enhanced Raman spectroscopy has the advantage of overcoming the low sensitivity and fluorescence effects seen with conventional Raman spectroscopy. The spectra are obtained by applying an analyte onto a SERS-active metal substrate such as colloidal metal particles. SERS signals can be further increased with the addition of aggregate solutions. These agents cause the nanoparticles to amass and form hot-spots which increase the signal intensity. In this work, the colloidal particles are spherical gold nanoparticles in aqueous solution with an average size of approximately 30 nm. The optimum aggregating agent for the detection of benzodiazepines was determined to be 16.7 mM MgCl2, providing the highest signal intensities at the lowest drug concentrations with limits of detection between 0.5 and 127 ng/mL. A supported liquid extraction technique was utilized as a rapid clean extraction for benzodiazepines from urine at a pH of 5.0, allowing for clean extraction with limits of detection between 6 and 640 ng/mL. It was shown that at this pH other drugs that are prevalent in urine samples can be removed providing the selective detection of the benzodiazepine of interest. This technique has been shown to provide rapid (less than twenty minutes), sensitive, and specific detection of benzodiazepines at low concentrations in urine. It provides the forensic community with a sensitive and specific screening technique for the detection of benzodiazepines in drug facilitated assault cases.