Bullet and cartridge case evidence may potentially link weapons and crimes through the comparison of toolmark patterns. This analysis relies on the clarity of the toolmarks and the ability of the examiner to identify patterns on the evidence. These patterns may be distorted by debris such as soil, blood, cyanoacrylate, and construction materials. Despite the potential importance of bullet and cartridge case evidence, few investigations of proper cleaning methods have been conducted. The present study was designed to examine the effects of various cleaning solutions and application methods on copper and brass bullets and cartridge cases. Additionally, this research investigated the efficacy of these cleaning protocols on the common evidence contaminants blood and cyanoacrylate. No cleaning method was found to be universally effective on both contaminant types and nondestructive to the metal surface. Ultrasonication was the most efficient application method employed when used in conjunction with an appropriate cleaning solution. Acetone proved to be safe and successful at removing heavy cyanoacrylate deposits from brass cartridge cases without damaging the metal. Although sulfuric acid removed most of the cyanoacrylate from the brass cartridge case, ultrasonication of the fumed cartridge cases in sulfuric acid caused the nickel-plated primer caps to turn black. Additionally, etching occurred when sulfuric acid was allowed to dry on the cartridge case surface. Citric acid, salt-flour-vinegar paste, Tergazyme®, and water did not effectively remove the cyanoacrylate from the cartridge cases, but the solutions were safe to use on the brass and sometimes resulted in a shinier surface. Regardless of the cleaning method employed, the bloodstained bullets retained most or all of the underlying brown tarnish. Ultrasonication with sulfuric acid was successful at removing some blood-initiated tarnishing; however, the removal of residues was not complete, making it difficult to visualize the full striation pattern. Citric Acid, Tergazyme®, and water proved to be safe to use on the copper bullets and capable of removing loose debris, but the cleaning solutions did not effectively remove the brown tarnish. Flitz® Instant Brass and Copper Tarnish Remover caused damage to both sample types by causing etching to occur on the metal surface. Additionally, the Flitz® tarnish remover caused the brass cartridge cases to turn black over time. The use of the Sunshine Polishing Cloths left light scratches on the surface of the samples, demonstrating they are not suitable for cleaning toolmark evidence.

Saliva can be detected on items including cigarette butts, glassware, clothing, human skin and condoms, and the identification of saliva on these types of evidence may be important to provide linkages or investigative leads in forensic cases. Sometimes when the presence of saliva is indicated, the item will be sent for deoxyribonucleic acid (DNA) analysis and may be used for identification of individuals involved in a crime. The detection of saliva mostly depends on the activity and the presence of amylase. The SERATEC® Amylase Test (SERATEC GmbH, Goettingen, Germany) is a lateral flow immunochromatographic test that targets the presence of human α-Amylase using two monoclonal anti-human-α-Amylase antibodies. This study investigates the effectiveness of using the SERATEC® Amylase Test to detect amylase on cigarette butts and vaping devices. In addition, the possible correlation between the SERATEC® Amylase Test result and the amount of DNA extracted from cigarette butt samples is evaluated. Results indicated that the cigarettes and vaping devices tested had no inhibitory effect on the SERATEC® Amylase Test. The SERATEC® Amylase test was able to detect amylase from various brands of cigarettes, marijuana cigarettes, JUULpods™ (JUUL Labs™ Inc., San Francisco, CA) and an additional vaping device. Negative amylase test results (22 of 114 samples) may be attributable to personal smoking habits and the texture of the cigarette butt wrap paper or vaping device. DNA quantification results indicated that the majority of cellular material was retained on the wrap paper even after submersion in the SERATEC® Amylase Test buffer. It is recommended that the wrap paper from the cigarette filter and the remaining extract from preliminary testing be combined prior to DNA extraction in order to maximize total DNA recovered from a cigarette sample. The correlation between the SERATEC® Amylase Test result and the quantity of DNA extracted from the same source was not linear. The presence of saliva and DNA concentration are controlled by different factors, thus using the detection of saliva to predict the recoverability of DNA on cigarettes may be valuable in some situations, but is not precise.

No description available.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine (MMed), Johannesburg, 2018 / Mob justice fatalities are a gross violation of human rights in that they represent extra-legal punishment. There is a paucity of research relating to the demographics of at-risk groups, nature of injuries and the impact to the Forensic Pathology Service (FPS). This was a retrospective study over 10 years at Germiston Forensic Pathology medico-legal service. The objectives were to describe the demographics of the deceased, identify the profile of at-risk groups, describe the trends of the number of fatalities and causes of death over time, assess hospitalisation frequency, describe the nature and location of injuries sustained, and to report on ancillary investigations performed. Data was collected from the South African Police Service (SAPS) 180 scene investigation record form, hospital notes, final post mortem report, Notification of death (BI1663) form and additional statements. 354 cases were analysed. There was no clear trend in the number of mob justice fatalities. Six areas were highlighted to have a higher incidence of mob justice fatalities. The at-risk population was young to middleaged black South African males. The majority of deaths were due to blunt force head injury, and were so severe that most deaths occurred within 24 hours of injury. A standardised operating procedure should be developed for uniformity in managing mob justice cases. Adequate resources should be distributed to appropriate departments to enable a reasonable turnaround time of ancillary investigations and high incidence areas should receive sufficient and appropriately skilled resources to engage with and monitor the respective communities to curb these killings. / XL2019

Limited experimentation has been conducted on fractography of fresh versus dry bones. The present project examined the presence of select fractographic features on wet and dry bone specimens over a time interval of 15 months. The experimental remains consisted of a total of 81 white-tailed deer (Odocoileus virginianus) long bones as a proxy for human long bones. A subsample of 15 long bones that were defleshed of most external soft tissue was subjected to blunt force trauma every 30 days for a total of three months. After these three months passed, a subsample of 15 bones was subjected to blunt force trauma every 90 days for the remaining 12 months. Following fracturing, the long bones were macerated and the fractures on the long bones were inspected, and observations were recorded and photographed. The author hypothesized that the presence (or absence) of fractographic features including hackle patterns, bone mirror, cantilever curls, and arrest ridges, on the fractured long bones would differ on fresh versus dry bones. Therefore, the difference in fractographic features found on the fresh versus dry bones would allow greater separation of perimortem from postmortem fractures. Other fracture characteristics such as fracture angle, fracture surface texture, fracture jaggedness, number of fragments produced, and type of fracture produced were also observed as part of the data collected in this research to potentially confirm the findings and results of previous studies conducted on differentiating between perimortem and postmortem trauma on bone. This study disproved the hypothesis by concluding that the presence (or absence) of fractographic features is not greatly affected by time exposure and therefore, does not aid in distinguishing between fresh bone and dry bone fractures. Fractographic features were present and absent on bone specimens during all postmortem intervals. The only statistically significant difference discovered was that bone hackle patterns are more commonly observed than cantilever curls on bones with a later PMI. Other general trends observed were that the number of bones showing bone hackle patterns increased over time and the number of bones showing bone mirror decreased over time. In addition, the results of the study revealed that the only fracture characteristic that showed a slightly significant difference with time of exposure was the fracture surface texture produced. The probability of a bone showing intermediate fracture surfaces is statistically significantly higher than a bone showing rough fracture surfaces when the represented PMI is fresh. The probability of a bone showing intermediate fracture surfaces is statistically significantly higher than a bone showing smooth fracture surfaces when the represented PMI is dry. The present study showed that the fracture characteristics including fracture angle, fracture type, number of fragments produced, and fracture jaggedness were not greatly influenced by exposure of time but, certain patterns and trends were recognized. The number of bones showing sharp fracture angles increased over time, while the number of bones showing intermediate fracture angles stayed stagnant. Bones showing comminuted fractures also increased with the progression of drying time. The average number of fragments produced were high during both fresh and dry PMIs and low throughout the transitional postmortem intervals. Bones showing jagged, intermediate, and not jagged broken ends increased with the progression of time however, not jagged broken ends only began to appear in the sample starting at a PMI of 90 days.

No description available.

No description available.

The behavioral immune system (BIS) is comprised of a variety of psychological and behavioral defenses designed to protect against pathogenic threats. These processes predict various affective and behavioral responses in myriad human contexts, including putative decisions to mitigate exposure to environmental pathogens. We investigated whether the strength of BIS responses predicted jurors’ verdicts in a sexual assault trial, wherein strength of the evidence against the defendant was manipulated (ambiguous vs. strong) to determine the extent to which chronic activation of BIS predicted derogation of the defendant. Subsequent mediation analyses indicated that dispositionally activated BIS (as indexed by perceived vulnerability to disease) predicted greater likelihood of conviction by way of affective experiences of disgust, which in turn influenced participants’ cognitive appraisals of diagnostic evidence. Furthermore, such responses also elicited greater desire for social distance with the defendant. Evidence strength, however, did not moderate these effects. Findings provide preliminary evidence for how BIS responses may influence legal proceedings.

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.

Sexual assault evidence composes a large portion of the evidence analyzed by forensic serologists. Key to the processing of sexual assault evidence is the screening of the evidence items for the presence of semen. Due to the intimate nature of a sexual assault, it is very possible that semen is mixed with other body fluids when it is deposited on an item of evidence. One of the body fluids that semen can easily come into contact with during a sexual assault is saliva. Saliva functions as the first step in the human body’s digestive system. Due to the digestive system’s purpose of breaking down nutrients, it stands to reason that saliva could play a role in breaking down seminal components. To detect semen, specific components of semen are tested for in forensic laboratories. These components are often acid phosphatase, prostate specific antigen, semenogelin, and spermatozoa. This experiment combined semen from one donor with saliva of seven other donors in a two part survey. In part one, semen was mixed with the saliva of Donors A, B, C, and D at three different ratios of 1:1, 1:2, and 1:10 semen-saliva. Twenty-microliter stains were pipetted onto one inch by one inch squares on twelve cotton swatches to test for acid phosphatase, prostate specific antigen, semenogelin, and spermatozoa. One set of six swatches was allowed to dry and the other set was kept damp. The stains were tested at six timepoints: day zero, day one, week one, week two, week three, and week four. Part two involved incubating the semen with saliva from Donors X, Y, and Z at body temperature for up to twenty-four hours. The same three ratios used in part one were repeated with the saliva from Donors X, Y, and Z in part two. A twenty microliter stain was pipetted onto a cotton swatch at each of the five timepoints from the start of the incubation period: zero minutes, one hour, five hours, eight hours, and twenty-four hours. Each stain was tested for acid phosphatase, prostate specific antigen, and semenogelin. The results of part one showed that semen samples that are mixed with saliva but allowed to dry are effectively unaffected by the presence of saliva. On the dry swatches, the stains tested positive for every component of semen at every timepoint for every donor except for Donor D’s 1:10 semen-saliva mixture stain, which tested negative for spermatozoa at week 1, but positive for spermatozoa in the subsequent timepoints. The results of the damp swatches suggests that damp environmental factors can prevent the detection of seminal components. By week two, the detection of spermatozoa had completely dropped out in the mixture stains and in the neat semen control stains. Detection of prostate specific antigen ceased in the control by week 3 and had also stopped in all 1:1 semen-saliva mixture stains by week 4. The detection of prostate specific antigen had stopped at week 3 for all donors in the 1:10 semen-saliva mixture stains. Semenogelin was still detectable in the control sample for the duration of the experiment, and it was detected for all donors at week 4 in the 1:1 and 1:2 semen-saliva mixture stains. Detection of semenogelin ceased in Donors B and D in the 1:10 semen-saliva mixture stains by week two. The results of part two suggested that the detection of acid phosphatase could be affected when semen and saliva have been incubating together at body temperature. Acid phosphatase was detected at all the timepoints in the neat semen control, but after eight hours, it was no longer detectable in all the mixture ratios of Donors X and Z. Acid phosphatase was no longer detectable in the 1:1 semen-saliva mixture stain of donor Y at eight hours and in the 1:2 semen-saliva mixture stain of Donor Y at twenty-four hours. Acid phosphatase did remain detectable in the 1:10 semen-saliva mixture stain of Donor Y through the twenty-four hour experimental period. Prostate specific antigen and semenogelin remained detectable in all the donors at all three ratios for the duration of the experiment.