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This thesis presents a validation study of the research by Hassett (2011). It examined the permanent canines’ cervical diameters using established measurement techniques set forth by Hillson et al. (2005) to determine sex in a known population of male and female adults and juveniles. The present study combined the Maxwell Collection, housed at University of New Mexico, and the Hamann-Todd Collection, housed at the Cleveland Museum of Natural History, as the known-sex sample. The sample included 642 permanent canines resulting in 862 measurements from 218 individuals. There were 120 males and 98 females between the ages of 12 and 98 years old. Of the 218 individuals, 148 were White, 62 were Black, 2 were Hispanic, 1 was Native American, and 5 were an unknown ancestry. The measurements used were the cervical mesiodistal diameter and the cervical buccolingual diameter of each upper and lower, right and left canine. The author hypothesized that research conducted on this known age skeletal collection sample would support Hassett (2011), who concluded that the cervical diameter of the canine is sexually dimorphic and can be used to predict sex accurately. In addition, it was predicted that there would not be a significant statistical difference between adult and juvenile permanent canine measurements. An intra-observer error test found that original and repeated measures were not statistically different from one another. Statistical analysis found that adults and juveniles did not have significantly different measurements, so the two samples were combined into one larger known-sex sample. The accuracy of all the functions for both sexes using the cervical diameter method is between 80.2% and 87.5%. The fourth function’s formula, which uses both diameters from one maxillary canine and one mandibular canine, had the best overall accuracy of 87.1%. The accuracy of all the functions for males was between 81.1% and 91.7% and for females the accuracy was between 74.8% and 89.7%. Analysis also indicated that no tooth nor measurement proved to be a better predictor of sex; therefore, any tooth and measurement can be used to estimate sex. The author believes that this validation will allow further research into the applicability of the permanent canine using cone-beam computed tomography to determine sex in juveniles whose permanent canines have not yet erupted. This determination is highly significant, given the dearth of usable techniques to sex juvenile human remains.

This study compares sexual variation of the human skeletal pelvis through geometric morphometric analyses. Digitization of the skeletal elements provides the framework for a multi-faceted examination of shape. The sample used in the study consists of individuals from the Bass Donated Skeletal Collection, located at the University of Tennessee-Knoxville. Landmarks digitized for the study are derived from the 36 points implemented in Joan Bytheway and Anne Ross’s geometric morphometric study of human innominates (2010). The author hypothesizes that morphological variation between males and females will be visible to varying degrees throughout the pelvis, with structures to be compared consisting of the ilium, ischium, pubis, obturator foramen, and acetabulum. Particular attention will be paid to the pelvic canal, as this area seems to carry the most sex-specific function of the bone. It is hypothesized that structures directly contributing to the pelvic canal will be more sexually dimorphic than peripheral structures. Data points plotted throughout the pelvis will allow for comparison of various regions. Results indicate that the innominate can be divided into modules with relatively low levels of covariation between them. Greatest amounts of sexual dimorphism are located at the pubis and ischium. The shape of the acetabulum and obturator foramen display little variation between the two sexes. Areas that have the potential for sex determination could be investigated more thoroughly in the future and may be of use in forensic cases in which remains are incomplete.

In any forensic investigation it is important to consider sample preservation. Oftentimes trace quantities of biological materials are found at crime scenes. The usual practice among forensic analysts is to take one sample of a suspected biological stain for presumptive testing, another for confirmatory testing and if both these results are positive, take a third portion for DNA analysis. This works well when sufficient sample is available, however, when trace quantities of sample are present at crime scenes, sample preservation becomes of importance. Thus, this study attempts to develop a procedure where presumptive, confirmatory and DNA analysis could be carried out on a single portion of the sample. In this study four different presumptive reagents – phenolphthalein, o-tolidine, 3, 3’, 5, 5’- tetramethylbenzidine (TMB) and luminol – were used and their effects on the ABAcard® Hematrace® immunochromatographic membrane test and subsequent DNA analysis were studied. In order to develop the method for one-sample analysis, the lowest volume of blood that gave sufficient quantity of DNA was determined by extracting different volumes (20, 10, 5, 2.5 and 1.25 μL) of whole blood. Additionally, different volumes of blood mixed with ABAcard® Hematrace® buffer were extracted. From this preliminary work it was determined that 1.25 μL of whole blood yielded sufficient DNA quantity even when mixed with the ABAcard® Hematrace® buffer. Bloodstains of 1.25 μL were then prepared and the one-sample analysis was carried out. The method developed was most successful when luminol was used as the presumptive reagent. For the bloodstains treated with the other three presumptive reagents (phenolphthalein, o-tolidine and TMB), a decrease in DNA yield was detected. This decrease was attributed to the inability of the Qiagen® QIAmp® column to adsorb the DNA after exposure to the chemical reagents and to the insolubility of the bloodstain in ABAcard® Hematrace® buffer following the addition of presumptive blood test reagents. Extraction of DNA from the ABAcard® Hematrace® immunochromatographic membrane was also carried out using the Qiagen® QIAmp® DNA investigator kit; no DNA was obtained from the membranes on which 150 μL of a dilute blood sample had been applied. This suggests that either the extraction method used was not capable of extracting the minute quantities of DNA that might be present on the membrane or there were insufficient white blood cells deposited on the membrane during the testing process. Thus, a one-sample procedure was successfully developed for bloodstains treated with luminol. A loss/reduction of DNA was observed for the samples previously exposed to phenolphthalein, o-tolidine and TMB due to the incapability of the reagents to work with silicon-based extraction chemistries. Further experimentation is needed to develop a similar procedure to be used with such presumptive testing reagents. Alternatively, a procedure can be developed that utilizes two samples: one for presumptive testing and another for confirmatory and subsequent DNA analysis, since it was observed that only the presumptive reagents, and not the ABAcard® Hematrace® buffer, interfered with DNA analysis.

The use of polymerase chain reaction (PCR) has revolutionized DNA typing in forensic laboratories. Producing a deoxyribonucleic acid (DNA) profile now requires less time and less DNA than before. However, not all evidence samples can be reliably profiled, particularly those with low masses of DNA. These samples often exhibit stochastic effects such as allele dropout, elevated stutter and peak height imbalance, which are challenging to separate from true donor alleles. Several scholarly articles have documented these difficulties and suggest that these stochastic effects are due to uneven amplification of heterozygous alleles in early PCR. However, in early PCR all reaction components are at their maximum concentrations and should be able to amplify all alleles in a sample proportionate to their original concentrations. If both alleles are present in the sample at equal concentrations prior to PCR, both alleles should theoretically be amplified with the same efficiency; the fact that this is not the case suggests that there may already be variation within the sample. One possible reason is that pre-PCR sampling error from pipetting and sample transfers results in an uneven number of allele copies in the sample prior to amplification. Thus, it may not be PCR chemistry alone that contributes to stochastic effects, but also sampling error, which creates unequal allele concentrations prior to PCR. In order to separate and study these possibilities, a single-tube DNA extraction method was developed. The forensicGEM™ Saliva kit developed by ZyGEM provides an extraction method that utilizes a thermostable proteinase found in a proprietary Bacillus species to lyse the cell and destroy nucleases without inhibiting downstream amplification. Combining this extraction protocol with the McCrone and Associates, Inc. cell transfer method allowed for the addition of cells directly to the PCR tube, giving an approximate DNA mass without quantitation. These samples should show the effects of PCR chemistry alone, with pipetting and tube transfer steps prior to amplification removed. For comparison, samples of bulk DNA extracted with forensicGEM™ Saliva were diluted down to a comparable concentration and subjected to multiple transfer steps in an effort to identify both pre-PCR sampling error and any error due to PCR chemistry. Results show that the single-tube extraction method gives reliable results, with forensicGEM™ Saliva showing comparable peak heights (PH) and peak height ratios (PHR) to the Qiagen QIAmp DNA Investigator kit and the cell transfer method providing accurate DNA concentrations with minimal PCR inhibition. Comparison of the cell transfer-generated samples to the diluted bulk DNA samples showed that the cell transfer samples had higher average PHRs at 0.0625 ng of target DNA when amplified with Identifiler® Plus, but showed no significant difference between the sample types at 0.125 ng of target DNA. The cell transfer samples were also shown to have lower overall PHs at both concentrations and a higher occurrence of allelic dropout, but only when amplified with the Identifiler® kit; when amplified with Identifiler® Plus, the occurrence of dropout was low for cell transfer and bulk DNA samples at both concentrations. These results suggest that as DNA mass decreases, pre-PCR sampling error may contribute to the development of stochastic effects; however, the vast majority of stochastic effects are due to the PCR chemistry itself. As the PCR chemistry improves and the prevalence of stochastic effects decreases, the importance of pre-PCR sampling error may increase.

Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification-highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications-highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

Trasology and its use in crime investigation Abstract Title of this thesis is Trasology and its use in crime investigation. This thesis focus on trasology which is discipline of forensic science examining foot traces, traces of other body parts and traces of vehicles. The objective of this thesis is to provide its reader basic summary about this discipline of forensic science and methods used in this discipline especialy aplication of biomechanincs in trasology and height estimation from foot prints dimensions. This thesis is divided into eleven chapters. First chapter after introducing chapter is chapter about history of trasology, folowing chapters describe individual groups of trasological traces. Folowing chapters focus on methods of detecting and capturing trasological traces. Chapters number seven and eight are about methods of forensic examination of trasological traces. Main part of this thesis consist of chapter about aplication of biomechanics in trasology and experimental chapter presenting results of comparison of methods of height estimetion from foot prints dimensions. Biomechanics is used in trasology mainly for estimation of height from traces of various body parts. In the experimental chapter you can find comparison of six methods of height estimation from length and breadth of foot traces....

Human hair is a relatively inert biopolymer and can survive through natural disasters. It is also found as trace evidence at crime scenes. Previous studies by FTIRMicrospectroscopy and – Attenuated Total Reflectance (ATR) successfully showed that hairs can be matched and discriminated on the basis of gender, race and hair treatment, when interpreted by chemometrics. However, these spectroscopic techniques are difficult to operate at- or on-field. On the other hand, some near infrared spectroscopic (NIRS) instruments equipped with an optical probe, are portable and thus, facilitate the on- or at –field measurements for potential application directly at a crime or disaster scene. This thesis is focused on bulk hair samples, which are free of their roots, and thus, independent of potential DNA contribution for identification. It explores the building of a profile of an individual with the use of the NIRS technique on the basis of information on gender, race and treated hair, i.e. variables which can match and discriminate individuals. The complex spectra collected may be compared and interpreted with the use of chemometrics. These methods can then be used as protocol for further investigations. Water is a common substance present at forensic scenes e.g. at home in a bath, in the swimming pool; it is also common outdoors in the sea, river, dam, puddles and especially during DVI incidents at the seashore after a tsunami. For this reason, the matching and discrimination of bulk hair samples after the water immersion treatment was also explored. Through this research, it was found that Near Infrared Spectroscopy, with the use of an optical probe, has successfully matched and discriminated bulk hair samples to build a profile for the possible application to a crime or disaster scene. Through the interpretation of Chemometrics, such characteristics included Gender and Race. A novel approach was to measure the spectra not only in the usual NIR range (4000 – 7500 cm-1) but also in the Visible NIR (7500 – 12800 cm-1). This proved to be particularly useful in exploring the discrimination of differently coloured hair, e.g. naturally coloured, bleached or dyed. The NIR region is sensitive to molecular vibrations of the hair fibre structure as well as that of the dyes and damage from bleaching. But the Visible NIR region preferentially responds to the natural colourants, the melanin, which involves electronic transitions. This approach was shown to provide improved discrimination between dyed and untreated hair. This thesis is an extensive study of the application of NIRS with the aid of chemometrics, for matching and discrimination of bulk human scalp hair. The work not only indicates the strong potential of this technique in this field but also breaks new ground with the exploration of the use of the NIR and Visible NIR ranges for spectral sampling. It also develops methods for measuring spectra from hair which has been immersed in different water media (sea, river and dam)

Thesis (M.S.F.S.) / Swabs are an integral part of any forensic science “toolkit”. They can be used to gather many types of evidence at crime scenes, in the lab, or even in the hospital or morgue. Cotton swabs have been the traditional choice for most forensic laboratories, and for sexual assault kits. They have been the obvious choice for decades as cotton swabs were really the only option and they were and still are relatively inexpensive and easy to obtain. In the past dozen years or so, new synthetic fibers have been incorporated into novel swab designs. Fiber swabs can be made of polyester or rayon, polyurethane foam swabs can be round, narrow, oval or arrow shaped; swabs can also be flocked, or sprayed with strands of material such as nylon. The effectiveness of any type of swab used to collect biological material is based on three characteristics: the ability to pick up the material for which they are designed, the ability to hold that material until processed and then the ability to release as much of that material as possible to be analyzed in the lab. In this study, the efficacy of four different commercially available swabs to collect, store and release spermatozoa was evaluated. Puritan Cotton fiber swabs, Fisher Polyester fiber swabs, Fisher polyurethane swabs, and Copan nylon flocked swabs were all compared for their ability to pick-up and elute cells from solid surfaces. The surfaces included three types of commonly found tile: a smooth glossy ceramic tile, a rough non-porous ceramic tile, and a smooth semi-porous quarry tile. In general, polyester fiber swabs outperformed both the polyurethane foam and the nylon flocked swab when used on all three surfaces (P < 0.05). Polyester swabs were not significantly different from the cotton fiber swabs even though the average number of cells picked-up and eluted was higher overall. Swabs used to collect postcoital samples were also compared. Volunteer couples were given a variety of swabs to use after intercourse. The result of the comparison for the same four swab types when used as postcoital swabs was different from the results of the tile study. After estimating the number of cells collected and released from each swab, a comparison was made within each couple. Nylon flocked swabs yielded the highest level of cellular material overall and foam swabs recovered the least. This study demonstrates the need for further research into different swab types and in what capacities they are to be used in forensic science.

Thesis (M.S.F.S.) / Positive identification of skeletonized human remains is a difficult task when dental records and/or DNA are unavailable. Through archaeological research, strontium (Sr) isotope analysis has successfully been used to trace an individual back to their place of birth using cortical bone and tooth enamel. This method has the potential, in forensic anthropological science, to help narrow down the search for missing persons to a specific geographical location. It has not been tested thoroughly on modern populations though, which is needed before applying in a forensic setting. This study used dental enamel from teeth of 78 individuals in the New England region of the United States (U.S.). The birthplaces represented by these individuals include New England and the greater Northeast of the U.S., Northwest region of the U.S., Central America, Caribbean Islands, West Africa, and Europe. Local faunal and water samples were also collected for local range comparisons. The samples were cleaned, approximately 10 mg of enamel removed from each tooth, acid washed, dried, and dissolved in nitric acid before analyzing the samples using a thermal ionization mass spectrometer (TIMS) for analysis of 87Sr/86Sr ratios. The human 87Sr/86Sr ratios were grouped by geographical region. An analysis of variance was used to test for regional variation and significant differences were found. The samples from the U.S. (excluding those from the Northwest) were significantly different from the samples in Central America, Caribbean Islands, West Africa, and Europe. Central American samples were also significantly different from the other groups. No significant differences were observed between the Caribbean Islands, West Africa and Europe. A significant difference was seen between the strontium ratios in the West Africa group based on bottled water vs. tap water that individuals reported drinking. The faunal samples from Pembroke, MA and water sample from Braintree, MA were not significantly different from the New England human samples, but the Brighton, MA water sample was significantly different. Based on the data, regional differences in 87Sr/86Sr ratios are detectable using strontium isotope analysis, yet a larger sample size for each of the regions is needed to strengthen the statistical results. The results suggest that the differences observed are due to a combination of geological effects and influences from the globalization of food. Further research is warranted by combining the analysis of hydrogen (δ2H) and oxygen (δ18O) isotopes to the strontium analysis. This will complement the strontium data by providing more insight to the local drinking water and potential effects of an increasingly homogenous diet within cultural regions.