Ideally a DNA profile will have high Peak Heights (PHs), balanced Peak Height Ratios (PHRs) and no drop out. However, low template DNA (LTDNA) is limited in quantity, quality or both and LTDNA profiles do not always consistently provide interpretable signal. Post-Polymerase Chain Reaction (PCR) purification is an efficient enhancement method that can be utilized to increase the amount of information in a LTDNA profile without elevated stutter, which can be common with other enhancement methods. Post-PCR purification decreases the remaining components left over from amplification, such as deoxyribonucleotide triphosphates, primers, salts, and enzymes so there is less competition during the electrokinetic injection and more DNA will go into the capillary. When post-PCR purification is used; PH’s will increase, PHRs should remain stable before and after purification and may result in recovery of alleles that previously had dropped out. Allele recovery may be the difference between an inconclusive result and an inclusion or exclusion. The efficacy of Post-PCR purification was assessed by amplifying single source DNA with both ABI AMPFℓSTR® Identifiler® (template mass down to 0.0625 ng) and Identifiler® PLUS (template mass down to 0.03125 ng) and performing post-PCR purification with Qiagen® MinElute® and Macherey-Nagel NucleoSpin®. The original amplified product and purified product were analyzed and compared and it was determined post-PCR purification reduced the primer front, increased the PHs, recovered additional alleles and did not affect the PHRs. On average the Fold Increase (FI) for Identifiler® product purified with Qiagen® MinElute® is 3.5 and the average FI for Identifiler® PLUS product purified with Qiagen® MinElute® and Macherey-Nagel NucleoSpin® is 3.2. Additionally, the stutter percentage observed in the original sample profile was compared to the purified samples to determine if purification affected the stutter percentage of Identifiler® PLUS product. It was determined at only a few alleles the amplified product was above or below the stutter percentage of purified product. The stutter percentage values for purified samples were further compared to the Identifiler® PLUS manual and only one allele’s stutter percentage is above the companies stutter cut off values. Post-PCR purification with Qiagen® MinElute® or Macherey-Nagel NucleoSpin® is a successful enhancement method to increase information of a LTDNA profile without introducing additional complications that other enhancement methods are known to do.

Arson cases involve the collection and interpretation of a variety of evidence. Though some analysis such as the identification of accelerants has been heavily researched and tested, other areas have limited research and need to be addressed. The goal of this research is to assess the damage various fabric types face when exposed to high temperatures, open flames, and various chemicals. To answer this question I exposed polyester, cotton, nylon, spandex as well as polyurethane coated nylon and polyester to temperatures up to 300°C, open flame, gasoline, and bleach. The color, damage, and type of damage were assessed and reported. The synthetic fabric category showed considerable resistance to dye loss when exposed to the stimuli above and melted when exposed to high temperature and open flame. Cotton, a natural fiber, showed signs of color loss in all tests aside from gasoline exposure. Additionally, when exposed to high temperature and open flame, cotton would dehydrate, discolor, and char. To improve the assessment of fabrics in arson related cases it is necessary to create a uniform understanding of how various fabric and fibers respond to various exposures.

The research presented in this dissertation describes the design and synthesis of substitutional-solid-solution-based multivariate metal-organic frameworks (SSS-based MTV MOFs) with functionalized organic linkers to study their emergent properties in the crystalline solid state. The synthetic versatility and tunability of organic chemistry coupled with the predictable organization of inorganic structures enables MTV MOF systems to further the fundamental understanding of structure-composition-property relationships for the targeted design of applied materials due to their ability to control the structure, composition, and property independently. To begin, a set of terphenyl linkers with varied steric and electronic properties were crystallized as a family of UiO-type MOFs to assess their effects on the uptake and separation of noble gases. This series was then isoreticularly expanded to PEPEP linkers and combined in a PIZOF-type MTV MOF system to evaluate its capability as a multivariate platform for linkers with different functional groups. Chapters 4, 5, and 6 each focus on a different advantageous aspect of the PIZOF system, first exploring the free volume in the pores where covalently bound redox active mediators demonstrate electron diffusion via charge-hopping mechanics to achieve redox conductivity. The next chapter studies the aggregate-induced emission properties that can arise from link-link interactions due to the interpenetrated structure of PIZOF-type frameworks by incorporating a pentacene-based linker in an MTV MOF series to determine its singlet fission potential. The last chapter utilizes the water stability of the PIZOF framework to investigate how increasing pore hydrophilicity through the inclusion of a rationally designed pentaerythritol-containing linker affects the water adsorption. This dissertation demonstrates the value of the SSS-based MTV MOF approach under the paradigm of reticular chemistry to enable the design of tunable and complex solid-state systems with the ability to deconvolute structure from composition and property, while still allowing for relationships between the structure, composition, and property.

Biological evidence is often found at crime scenes and can comprise of DNA from the victim(s) and perpetrator(s) to a crime as well as from individuals with no direct relationship to the incident. This can complicate analysis as DNA mixtures are one of the more difficult sources of biological evidence to interpret. Probabilistic genotyping (PG) has greatly aided in mixture analysis. However, even with PG, standard bulk mixture approaches do not always result in probative results as allele overlap, artifacts, or low-level minor contributors inevitably cause genotype information loss. Therefore, deconvolution of forensic DNA mixtures into their individual component DNA (geno)types is of great investigative value. In the present work, enhanced single cell DNA typing conditions consisting of reduced reaction volumes and increased PCR cycle number were optimized and paired with a simplified micro-manipulation technique resulting in a subsampling scheme referred to as direct single cell subsampling (DSCS). Furthermore, the PG systems STRmixTM and EuroForMix were validated for use with both standard bulk DNA mixtures as well as with 1-5 cells. The DSCS approach was applied to various complex mixture scenarios including equimolar 2-6 person mixtures, mixtures comprised of 1st degree relatives, mixtures in which a minor donor is virtually undetectable (~1:50), and mixtures that had been deposited for varying time periods resulting in a probative gain of information compared to the standard mixture methods. Specifically, with the 5- and 6- person complex mixtures analyzed, DSCS recovered highly probative LRs ( > 10^20) from donors that had returned non-probative LRs ( < 10^3) by standard methods. With familial mixtures, DSCS prevented the false inclusion of non-donor relatives seen with standard methods. This approach was further applied to Y-STR mixture analysis. The DSCS approach could permit forensic scientists to analyze and recover probative evidentiary information from complex mixtures with excessive overlapping alleles such as those seen with related individuals and large contributor numbers as well as from mixtures with marginally detectable minor donors. Requiring only basic equipment and materials, the DSCS approach can easily be implemented into a casework laboratory.

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Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / An in-depth review of relevant international literature in the field of death investigation was performed with the intention of assessing the complex ethical, legal, and medical considerations unique to the investigation of self-inflicted fatalities. The overall goal was to present a set of guidelines to be used in the development of more objective criteria for the determination of suicidal manner of death and to highlight the inherent difficulties in suicide investigation, which can often lead to misclassification at autopsy. Findings showed that suicides rates seem to fluctuate inversely to the number of deaths deemed as being of undetermined manner; this strongly suggests that many suicides are going unreported. There were also a significant number of case studies found which indicated conflicting scientific findings regarding gross anatomical or toxicological findings of suicide victims, and a number of others which showed cases of suicide which were intentionally disguised as either homicidal, natural, or accidental death and vice versa. The most commonly agreed upon signs of each method of suicide are summarized and suggestions for a consistent methodology for both scene investigation and autopsy are given. / 2031-01-01

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"Synthetic Cannabinoids are among newly synthetized drugs that have become widely known throughout the United States and around the world. Originally, these compounds were used by researchers to isolate the medicinal effects of natural cannabis. Ultimately these compounds found their way into the illicit drug market as an alternative to marijuana. Unfortunately, the pharmacology of synthetic cannabinoids is not known in detail but it has been confirmed that they elicit stronger, more often times negative effects compared to natural cannabis. The use of these compounds have resulted in cases of overdose and even death. The National Forensic Laboratory Information System (NFLIS) collects drug report information involving narcotics, stimulants, depressants, hallucinogens, cannabis, and emerging drugs such as anabolic steroids, phenethylamines, and synthetic cannabinoids, to name a few. They receive drug reports from forensic laboratories and perform statistical analysis to establish the prevalence of these drugs through out the United States. Specifically, the use of published NFLIS data sets from 2009-2013 and unpublished data set from 2013-2014 provided prevalence information from laboratories that have received synthetic cannabinoids in their forensic casework. The use of additional surveys and databases to supplement NFLIS data sets were used to better understand which particular groups of people are most likely to consume synthetic cannabinoids and in what specific regions. Understanding how common the abuse of synthetic cannabinoids provides information on how best to control them and potentially prevent health risks associated with their use. The prevalence of synthetic cannabinoid use has demonstrated an increasing-decreasing-increasing pattern throughout the years. The specific synthetic cannabinoids that have been identified in drug cases have changed over time to bypass the drug control laws. The future prevalence of these drugs is uncertain but knowledge of current patterns may help us to understand the state of this issue and plan for the future cases our forensic drug chemistry laboratories will face."

South Africa has one of the highest prevalences of drug misuse and abuse in Africa. Salt River Mortuary (Cape Town, South Africa), along with other national Forensic Pathology Service providers, receives many cases of suspected drug-related deaths. In some cases, the traditional autopsy – when viewed together with the decedent's history – is not able to indicate whether a drug-related death is accidental or suicidal in relation to altered drug metabolism. Literature has shown that this can be investigated by sequencing gene(s) encoding the implicated metabolising enzyme(s) in a postmortem genetic analysis. However, as such an analysis would normally be performed following the obtainment of postmortem toxicological results, it is imperative to investigate whether blood samples retrieved back from a toxicology laboratory would be sufficient for the said genetic analysis, despite the handling involved in the process of toxicological investigation. To this end, blood samples from 30 deceased individuals in which drug use/abuse may have contributed to death, were collected into two red-top tubes (plain), two grey-top tubes (containing sodium fluoride and potassium oxalate) and one EDTAcontaining purple-top tube (control). DNA was immediately extracted from one of each colour tube, while the duplicate red-top and grey-top tubes first underwent a process of toxicological analyses, and then underwent DNA extraction. The concentration, degradation, purity, contamination, and quality of DNA were assessed using real-time PCR, spectrophotometry, forensic DNA profiling, and Sanger sequencing. In contrast to the grey-top tubes, the results showed that the red-top tubes were most suitable for the aforementioned genetic analysis. Overall, the study not only demonstrated that postmortem genetic analysis using samples retrieved from a toxicology laboratory is possible in the local context, but also provided guidelines around the pre-analytical phase of the analysis. These results illustrate the opportunity to investigate these toxicogenetic avenues further, particularly in future expansion of services currently provided at Salt River Mortuary, which may provide families more information about circumstances of their relative’s death.