Showing papers in "Journal of Forensic Sciences in 2009"
TL;DR: This research focuses on the frequency distribution and inter‐trait correlations of 11 common morphoscopic traits to demonstrate that the experience‐based approach to ancestry prediction is indeed an art that is unscientific, because it is unreplicable, unreliable, and invalid.
Abstract: Historically, when predicting the ancestry of human skeletal remains, forensic anthropologists have not fully considered the variation within human populations, but instead have relied on a typological, experience-based approach. Unfortunately, reliance on observer experience has produced a method that is as much an art as it is a science. This research focuses on the frequency distribution and inter-trait correlations of 11 common morphoscopic traits to demonstrate that the experience-based approach to ancestry prediction is indeed an art that is unscientific, because it is unreplicable, unreliable, and invalid. Ten of 11 traits examined had frequency distributions with significant differences (p < 0.001) between groups, but the range in variation of these traits far exceeds previous assumptions. Such within group variation clearly demonstrates that extreme trait expressions are not reliable for estimating ancestry through visual observation alone, but instead that these traits should be analyzed within a statistical framework.
207 citations
TL;DR: It is believed it is possible and advisable for anthropologists to seek and espouse research and methodological techniques that meet higher standards to ensure quality and consistency in the authors' field.
Abstract: As issues of professional standards and error rates continue to be addressed in the courts, forensic anthropologists should be proactive by developing and adhering to professional standards of best practice. There has been recent increased awareness and interest in critically assessing some of the techniques used by forensic anthropologists, but issues such as validation, error rates, and professional standards have seldom been addressed. Here we explore the legal impetus for this trend and identify areas where we can improve regarding these issues. We also discuss the recent formation of a Scientific Working Group for Forensic Anthropology (SWGANTH), which was created with the purposes of encouraging discourse among anthropologists and developing and disseminating consensus guidelines for the practice of forensic anthropology. We believe it is possible and advisable for anthropologists to seek and espouse research and methodological techniques that meet higher standards to ensure quality and consistency in our field.
158 citations
TL;DR: Validation of this new technique for the rapid screening of forensic evidence for drugs of abuse, utilizing the DART source coupled to an accurate mass time‐of‐flight mass spectrometer was conducted.
Abstract: The Direct Analysis in Real Time (DART) ion source is a relatively new mass spectrometry technique that is seeing widespread use in chemical analyses world-wide. DART studies include such diverse topics as analysis of flavors and fragrances, melamine in contaminated dog food, differentiation of writing inks, characterization of solid counterfeit drugs, and as a detector for planar chromatography. Validation of this new technique for the rapid screening of forensic evidence for drugs of abuse, utilizing the DART source coupled to an accurate mass time-of-flight mass spectrometer, was conducted. The study consisted of the determination of the lower limit of detection for the method, determination of selectivity and a comparison of this technique to established analytical protocols. Examples of DART spectra are included. The results of this study have allowed the Virginia Department of Forensic Science to incorporate this new technique into their analysis scheme for the screening of solid dosage forms of drugs of abuse.
151 citations
TL;DR: The intent of this paper is to promote more thought, provide assistance on many aspects for consideration, and to support that more formalized mixture interpretation guidelines are developed.
Abstract: Currently in the United States there is little direction for what constitutes sufficient guidelines for DNA mixture interpretation. While a standardized approach is not possible or desirable, more definition is necessary to ensure reliable interpretation of results is carried out. In addition, qualified DNA examiners should be able to review reports and understand the assumptions made by the analyst who performed the interpretation. Interpretation of DNA mixture profiles requires consideration of a number of aspects of a mixed profile, many of which need to be established by on-site, internal validation studies conducted by a laboratory's technical staff, prior to performing casework analysis. The relevant features include: criteria for identification of mixed specimens, establishing detection and interpretation threshold values, defining allele peaks, defining nonallele peaks, identifying artifacts, consideration of tri-allelic patterns, estimating the minimum number of contributors, resolving components of a mixture, determining when a portion of the mixed profile can be treated as a single source profile, consideration of potential additive effects of allele sharing, impact of stutter peaks on interpretation in the presence of a minor contributor, comparison with reference specimens, and some issues related to the application of mixture calculation statistics. Equally important is using sensible judgment based on sound and documented principles of DNA analyses. Assumptions should be documented so that reliable descriptive information is conveyed adequately concerning that mixture and what were the bases for the interpretations that were carried out. Examples are provided to guide the community. Interpretation guidelines also should incorporate strategies to minimize potential bias that could occur by making inferences based on a reference sample. The intent of this paper is to promote more thought, provide assistance on many aspects for consideration, and to support that more formalized mixture interpretation guidelines are developed.
140 citations
TL;DR: The applicability of Raman spectroscopy and surface‐enhanced Raman scattering (SERS) to the analysis of synthetic dyes commonly found in ballpoint inks was investigated in a comparative study, finding it generally helpful.
Abstract: The applicability of Raman spectroscopy and surface-enhanced Raman scattering (SERS) to the analysis of synthetic dyes commonly found in ballpoint inks was investigated in a comparative study. Spectra of 10 dyes were obtained using a dispersive system (633 nm, 785 nm lasers) and a Fourier transform system (1064 nm laser) under different analytical conditions (e.g., powdered pigments, solutions, thin layer chromatography [TLC] spots). While high fluorescence background and poor spectral quality often characterized the normal Raman spectra of the dyes studied, SERS was found to be generally helpful. Additionally, dye standards and a single ballpoint ink were developed on a TLC plate following a typical ink analysis procedure. SERS spectra were successfully collected directly from the TLC plate, thus demonstrating a possible forensic application for the technique.
132 citations
TL;DR: DNA identification rates by element type conform to previous findings, with higher rates generally found in denser, weight‐bearing bones, but smaller bones including patellae, metatarsals, and foot phalanges yielded rates comparable to both femora and tibiae.
Abstract: The World Trade Center (WTC) victim identification effort highlights taphonomic influences on the degradation of DNA from victims of mass fatality incidents. This study uses a subset of the WTC-Human Remains Database to evaluate differential preservation of DNA by skeletal element. Recovery location, sex, and victim type (civilian, firefighter, or plane passenger) do not appear to influence DNA preservation. Results indicate that more intact elements, as well as elements encased in soft tissue, produced slightly higher identification rates than more fragmented remains. DNA identification rates by element type conform to previous findings, with higher rates generally found in denser, weight-bearing bones. However, smaller bones including patellae, metatarsals, and foot phalanges yielded rates comparable to both femora and tibiae. These elements can be easily sampled with a disposable scalpel, and thus reduce potential DNA contamination. These findings have implications for DNA sampling guidelines in future mass fatality incidents.
127 citations
TL;DR: It is concluded that preference of method of suicide in men and women is complexly determined and availability, accessibility, popularity, and socioacceptability seem to be the major determinants in the choice of methods among males and females rather than violence associated and lethality of the method.
Abstract: Suicide is an important public health hazard worldwide. A 4-year retrospective study from January 2000 to December 2003 was conducted to identify the favored methods in realized suicides among males and females in the west coastal region of India. During the study period, a total of 539 cases of suicidal deaths were autopsied. Males were predominantly affected (male: female-1.9:1). The age of the victims ranged from 13 to 90 years in males (mean = 40.1 years, median = 37.0 years) and 15 to 85 years in females (mean = 36.6 years, median = 32.0 years). Most favored method of suicide amongst males and females was hanging (36.9%, n = 199) followed by poisoning (34.7%, n = 187). Male dominance was apparent for each method of suicide except for self-immolation. Males were relatively more likely to use hanging and poisoning while females were more likely to prefer drowning and self-immolation as methods of suicide. Relatively younger females (mean = 33.0 years, median = 32.0 years) preferred hanging as a method of suicide when compared to males (mean = 42.4 years, median = 40.0 years). Among females, significantly younger females resorted to hanging when compared to older females who preferred drowning. On investigating the various theories proposed for choice of suicide methods in males and females in different regions we conclude that preference of method of suicide in men and women is complexly determined. In this region, availability, accessibility, popularity, and socioacceptability seem to be the major determinants in the choice of methods among males and females rather than violence associated and lethality of the method. Females were as likely to use lethal and violent methods as males in this region.
114 citations
TL;DR: The results showed that fingerprint experts were influenced by contextual information during fingerprint comparisons, but not towards making errors, and novice participants were more influenced by the bias conditions and did tend to make incorrect judgments, especially when prompted towards an incorrect response by the biases prompt.
Abstract: This study was conducted to assess if fingerprint specialists could be influenced by extraneous contextual information during a verification process. Participants were separated into three groups: a control group (no contextual information was given), a low bias group (minimal contextual information was given in the form of a report prompting conclusions), and a high bias group (an internationally recognized fingerprint expert provided conclusions and case information to deceive this group into believing that it was his case and conclusions). A similar experiment was later conducted with laypersons. The results showed that fingerprint experts were influenced by contextual information during fingerprint comparisons, but not towards making errors. Instead, fingerprint experts under the biasing conditions provided significantly fewer definitive and erroneous conclusions than the control group. In contrast, the novice participants were more influenced by the bias conditions and did tend to make incorrect judgments, especially when prompted towards an incorrect response by the bias prompt.
113 citations
TL;DR: A list of recommendations ranging from further documentation to new research and validation to education and to accreditation is provided for consideration, which is a starting point for discussion that could foster further thought and input in developing an overarching strategic plan for enhancing the forensic sciences.
Abstract: The forensic sciences are under review more so than ever before. Such review is necessary and healthy and should be a continuous process. It identifies areas for improvement in quality practices and services. The issues surrounding error, i.e., measurement error, human error, contextual bias, and confirmatory bias, and interpretation are discussed. Infrastructure is already in place to support reliability. However, more definition and clarity of terms and interpretation would facilitate communication and understanding. Material improvement across the disciplines should be sought through national programs in education and training, focused on science, the scientific method, statistics, and ethics. To provide direction for advancing the forensic sciences a list of recommendations ranging from further documentation to new research and validation to education and to accreditation is provided for consideration. The list is a starting point for discussion that could foster further thought and input in developing an overarching strategic plan for enhancing the forensic sciences.
113 citations
TL;DR: The accelerated rate of decomposition and the signature markings on the bones should be considered when interpreting taphonomic events and determining an accurate postmortem interval at vulture‐modified scenes.
Abstract: From July through September 2007, three pig carcasses (Sus scrofa), weighing between 27 and 63 kg were placed outside in a grassy area in central Texas. A surrounding fence prevented entrance by terrestrial scavengers, while allowing avian scavengers unrestricted access. A fourth pig carcass served as a control for the rate of decomposition and was placed in a cage that prevented terrestrial and avian animal access. Modification of the carcasses was recorded through the use of two motion-sensing digital cameras and daily on-site observations. American black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) waited c. 24 h before beginning to scavenge and completely skeletonized the carcasses in 3 to 27 h of feeding, leaving scratches on the bones. The accelerated rate of decomposition and the signature markings on the bones should be considered when interpreting taphonomic events and determining an accurate postmortem interval at vulture-modified scenes.
107 citations
TL;DR: It is demonstrated that the humerus is an effective bone for the estimation of sex because even in a fragmentary state it can give high classification accuracy.
Abstract: Sex determination is the first essential step for positive identification when a decomposed body is recovered. Taking into consideration the population aspect of sexual dimorphism of the skeleton, the present study aimed to create a sex identification technique using osteometric standards, derived from a contemporary Cretan population. A total of 168 left humeri were measured according to standard osteometric techniques. The differences between the means in males and females were significant (p < 0.0005). About 92.3% of cases were correctly classified when all measurements were applied jointly. Stepwise procedure produced an accuracy rate of 92.9%. The most effective single dimension was vertical head diameter (89.9%). The current study provides standards for a population that has not been represented so far in the existing databases. It demonstrates that the humerus is an effective bone for the estimation of sex because even in a fragmentary state it can give high classification accuracy.
TL;DR: Rapid eye movement (REM) sleep behavior disorder (RBD) carries well‐documented, potential forensic consequences during RBD episodes that could possibly have been misinterpreted as suicidal or homicidal behavior.
Abstract: Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by loss of the muscle atonia of REM sleep, with release of complex and violent behaviors that are often attempted dream-enactments. This study reviewed the literature on RBD with regard to potentially lethal behavior. A total of 39-41 clinical cases of RBD associated with potentially lethal behaviors to self and/or others were found, involving a child and adults of all age groups, that manifested as choking/headlock (n = 22-24), defenestration/near-defenestration (n = 7), and diving from bed (n = 10). A total of 80.8% (n = 21) were males; 19.2% (n = 5) were females; mean age was 65.6 +/- (SD) 13.8 years (range: 27-81 years, and a child). (Gender/age data were not listed in the remaining cases.) An etiologic association of RBD with a neurologic disorder (or with pharmacotherapy of psychiatric disorders, n = 4) was present in 21-23 patients. Thus, RBD carries well-documented, potential forensic consequences during RBD episodes that could possibly have been misinterpreted as suicidal or homicidal behavior.
TL;DR: Evaluating third molars from 950 Hispanic individuals aged 12–22‚years using Demirjian’s schematic for crown and root formation found that Hispanic third molar development was 8–18‚months faster than American Caucasians as reported by Mincer, Harris and Berryman in 1993.
Abstract: Evaluating third molars from 950 Hispanic individuals aged 12-22 years using Demirjian's schematic for crown and root forma- tion found that Hispanic third molar development was 8-18 months faster than American Caucasians as reported by Mincer, Harris and Berryman in 1993. This represents a statistically significant increase. Earlier development was more apparent in the later stages F through H. Hispanic males reach developmental stages faster than Hispanic females and maxillary third molars reach developmental stages faster than mandibular third molars in both sexes. The earliest age observed for stages B-H (e.g., Stage H first observed at age 13.92 years in females) and the oldest age observed for Stages B-G were developed to facilitate age prediction of unknown individuals. Prediction tables for minimum and maximum age for an observed stage (e.g., if a female maxillary third molar is stage F it means she is older than 13 years) for each sex-jaw group were calculated.
TL;DR: A short tandem repeat multiplex assay has been successfully developed with 25 autosomal loci plus the sex‐typing locus amelogenin for a total of 26 amplified products in a single reaction, having the potential to benefit the forensic community for reference sample testing and complex relationship evaluation.
Abstract: A short tandem repeat multiplex assay has been successfully developed with 25 autosomal loci plus the sex-typing locus amelogenin for a total of 26 amplified products in a single reaction. Primers for the loci were designed so that all of the amplicons present were distributed from 65 base pairs (bp) to less than 400 bp within a five-dye chemistry design with the fifth dye reserved for the sizing standard. A multiplex design strategy was developed to overcome challenges encountered in creating this assay. The limits of the multiplex were tested, resulting in the successful amplification of a wide range of genomic DNA sample concentrations from 2 ng to as low as 100 pg with 30 cycles of PCR. The 26plex has the potential to benefit the forensic community for reference sample testing and complex relationship evaluation.
TL;DR: The influence of clothing and wrapping on carcass decomposition and arthropod succession was investigated to provide data to enable estimated postmortem interval in homicide investigations.
Abstract: The influence of clothing and wrapping on carcass decomposition and arthropod succession was investigated to provide data to enable estimated postmortem interval in homicide investigations. Six pig carcasses, Sus scrofa, were divided into three sample groups, each with a clothed carcass wrapped and a carcass wrapped with no clothes. Two more carcasses, one with no clothes or wrapping, the other with clothes and no wrapping were used as controls. The clothed or wrapped carcasses had larger visible maggot masses, which moved more freely and these carcasses took longer to dry out. The blow fly maggot masses were dominated by Chrysomya marginalis and Chrysomya albiceps. Oviposition occurred simultaneously on all carcasses. High temperatures in one case caused significant maggot mortality. The Coleoptera community was dominated by Silphidae, Thanathopilus micans larvae, Dermestidae, Dermestes maculatus adults and larvae, and Cleridae, Necrobia rufipes.
TL;DR: The combined functions of ATR‐FTIR spectromicroscopy are visual searching of particles in fingerprints and measuring the FTIR spectra of the particles, which make it possible to directly identify whether a suspect has handled explosives from the fingerprints alone.
Abstract: The application of attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectromicroscopy for detection of explosive particles in fingerprints is described. The combined functions of ATR-FTIR spectromicroscopy are visual searching of particles in fingerprints and measuring the FTIR spectra of the particles. These functions make it possible to directly identify whether a suspect has handled explosives from the fingerprints alone. Particles in explosive contaminated fingerprints are either ingredients of the explosives, finger residues, or other foreign materials. These cannot normally be discriminated by their morphology alone. ATR-FTIR spectra can provide both particle morphology and composition. Fingerprints analyzed by ATR-FTIR can be used for further analysis and identification because of its non-destructive character. Fingerprints contaminated with three different types of explosives, or potential explosives, have been analyzed herein. An infrared spectral library was searched in order to identify the explosive residues. The acquired spectra are compared to those of finger residue alone, in order to differentiate such residue from explosive residue.
TL;DR: The study shows that differences in total fatty acid composition between species need to be considered when interpreting results from experimental decomposition studies using pigs as human body analogs.
Abstract: The early stages of adipocere formation in both pig and human adipose tissue in aqueous environments have been investigated. The aims were to determine the short-term changes occurring to fat deposits during decomposition and to ascertain the suitability of pigs as models for human decomposition. Subcutaneous adipose tissue from both species after immersion in distilled water for up to six months was compared using Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry. Changes associated with decomposition were observed, but no adipocere was formed during the initial month of decomposition for either tissue type. Early-stage adipocere formation in pig samples during later months was detected. The variable time courses for adipose tissue decomposition were attributed to differences in the distribution of total fatty acids between species. Variations in the amount of sodium, potassium, calcium, and magnesium were also detected between species. The study shows that differences in total fatty acid composition between species need to be considered when interpreting results from experimental decomposition studies using pigs as human body analogs.
TL;DR: The morphometric parameters of the hand show considerable sexual dimorphism in the Indian population while the hand and palm index remain poor sex indicators, and hand breadth has the highest accuracy of sex determination in the study group.
Abstract: When dismembered human remains are encountered, the decedent's sex may not be obvious. For these scenarios, techniques for sex determination may play a vital part of the medicolegal investigation. Five hundred hands (230 males, 270 females) from North and South Indian region were studied to investigate sexual dimorphism in hand dimensions (hand length, hand breadth, and palm length). The hand index (hand breadth/hand length x 100) and the palm index (hand breadth/palm length x 100) were derived. The hand dimensions show a higher accuracy in sex determination when compared to indices. Of all hand dimensions, hand breadth has the highest accuracy of sex determination in the study group. The sex differences were found to be statistically significant only for the hand index on the left side. The morphometric parameters of the hand show considerable sexual dimorphism in the Indian population while the hand and palm index remain poor sex indicators. The study thus has medicolegal implications when a dismembered hand is brought for examination.
TL;DR: The PrepFiler™ Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples and facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials.
Abstract: The PrepFiler Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples. The kit facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials: 0.1 and 40 microL of human blood (donor 2) provided 14 and 2883 ng of DNA, respectively. Following the revised SWGDAM guidelines, performance of the developed method was investigated using different sample types including saliva on swabs, semen stains on cotton fabric, samples exposed to environment, samples with polymerase chain reaction (PCR) inhibitors, blood stains (on denim, cotton cloth, and FTA paper), and touch evidence-type samples. DNA yields for all samples tested were equal or better than those obtained by both phenol-chloroform extraction and commercial kits tested. DNA obtained from these samples was free of detectable PCR inhibitors. Short tandem repeat profiles were complete, conclusive, and devoid of PCR artifacts.
TL;DR: There is an urgent need to reduce the growing backlog of forensic examinations in Digital Forensics Laboratories (DFLs), and the need to update training and establish thresholds in DFLs is addressed.
Abstract: There is an urgent need to reduce the growing backlog of forensic examinations in Digital Forensics Laboratories (DFLs). Currently, DFLs routinely create forensic duplicates and perform in-depth forensic examinations of all submitted media. This approach is rapidly becoming untenable as more cases involve increasing quantities of digital evidence. A more efficient and effective three-tiered strategy for performing forensic examinations will enable DFLs to produce useful results in a timely manner at different phases of an investigation, and will reduce unnecessary expenditure of resources on less serious matters. The three levels of forensic examination are described along with practical examples and suitable tools. Realizing that this is not simply a technical problem, we address the need to update training and establish thresholds in DFLs. Threshold considerations include the likelihood of missing exculpatory evidence and seriousness of the offense. We conclude with the implications of scaling forensic examinations to the investigation.
TL;DR: It was found that curve transverse and spiral fractures were prevalent in femora, while longitudinal fractures were popular in fibulae, indicating that fracture types may play a role in characterizing some wounds caused by chopping weapons.
Abstract: The characterization of wounds in bone caused by chopping weapons has been based on either semi-fleshed or defleshed specimens. This approach has not been adequately justified as reflecting actual cases involving fleshed bone. Likewise, the histological appearance of features in chopping wounds also deserves further attention. We used 11 fresh pig (Sus scrofa) articulated hind limbs, including the femur, tibia, and fibula with contiguous surrounding flesh (including an intact epidermal layer), to receive wounds using two axes and two hatchets. Scanning electron microscopy analysis of these wounds exhibited osteon pullouts in the fracture surfaces of fleshed specimens, suggesting the attenuation of force by the surrounding flesh. Lamellar separation was also exhibited at the impact sites and fracture surfaces of both fleshed and defleshed specimens. A consistently rough morphology is characteristic of fracture surfaces while impact surfaces are smooth and yielded evidence of striations from each implement.
TL;DR: Results indicate that neither skeletal nor individual bone appearance are reliable indicators of subsequent mtDNA typing outcomes, while the type of bone assayed is.
Abstract: Mitochondrial DNA analysis of skeletal material is invaluable in forensic identification, although results can vary widely among remains. Previous studies have included bones of different ages, burial conditions, and even species. In the research presented, a collection of human remains that lacked major confounders such as burial age, interment style, and gross environmental conditions, while displaying a very broad range of skeletal degradation, were examined for both mitochondrial DNA (mtDNA) quality and quantity. Overall skeletal weathering, individual bone weathering, and bone variety were considered. Neither skeletal nor bone weathering influenced DNA quality or quantity, indicating that factors that degrade bone do not have the same effect on DNA. In contrast, bone variety, regardless of weathering level, was a significant element in DNA amplification success. Taken together, the results indicate that neither skeletal nor individual bone appearance are reliable indicators of subsequent mtDNA typing outcomes, while the type of bone assayed is.
TL;DR: The Quantifiler Duo DNA Quantification kit enables simultaneous quantification of human DNA and human male DNA as well as detection of inhibitors of PCR in a single real-time PCR well as mentioned in this paper.
Abstract: The Quantifiler Duo DNA Quantification kit enables simultaneous quantification of human DNA and human male DNA as well as detection of inhibitors of PCR in a single real-time PCR well. Pooled human male genomic DNA is used to generate standard curves for both human (ribonuclease P RNA component H1) and human male (sex determining region Y) specific targets. A shift in the cycle threshold (C(T)) values for the internal positive control monitors the presence of PCR inhibitors in a sample. The assay is human specific and exhibits a high dynamic range from 0.023 to 50 ng/microL. In addition, the multiplex assay can detect as little as 25 pg/microL of human male DNA in the presence of a 1000-fold excess of human female DNA. The multiplex assay provides assessment of the DNA extract and guidance for the selection of the appropriate AmpFlSTR Amplification Kit to obtain interpretable short tandem repeat profiles.
TL;DR: The Rapid Stain IDentification (RSID™‐Saliva) is described, a lateral flow immunochromatographic strip test that uses two antisalivary amylase monoclonal antibodies to detect the presence of salivaryAmylase, rather than the activity of the enzyme.
Abstract: Current methods for forensic identification of saliva generally assay for the enzymatic activity of alpha-amylase, an enzyme long associated with human saliva. Here, we describe the Rapid Stain IDentification (RSID-Saliva), a lateral flow immunochromatographic strip test that uses two antisalivary amylase monoclonal antibodies to detect the presence of salivary amylase, rather than the activity of the enzyme. We demonstrate that RSID-Saliva is accurate, reproducible, and highly sensitive for human saliva; RSID-Saliva detects less than 1 microL of saliva. The sensitivity of RSID-Saliva allows investigators to sample a fraction of a questioned stain while retaining the majority for DNA-STR analysis. We demonstrate that RSID-Saliva identifies saliva from a variety of materials (e.g., cans, bottles, envelopes, and cigarette-butts) and it does not cross-react with blood, semen, urine, or vaginal fluid. RSID-Saliva is a useful forensic test for determining which evidentiary items contain saliva and thus may yield a DNA profile.
TL;DR: Three criteria have been previously proposed for the discrimination of falls from homicidal blows in blunt head injuries: the hat brim line rule, side lateralization of fractures, and number of lacerations are combined.
Abstract: The discrimination of falls from homicidal blows in blunt head injuries is a common but difficult problem in both forensic anthropology and pathology Three criteria have been previously proposed for this distinction: the hat brim line rule, side lateralization of fractures, and number of lacerations The aim of the present study was to achieve a better distinction rate by combining those criteria and assess the predictability of these combined criteria tools Over a 6-year period, a total of 114 cases (92 males and 22 females) were studied: 21 cases of downstairs falls, 29 cases of falls from one's own height, and 64 cases of head trauma by a blunt weapon The results revealed predictability rates varying from 625 to 833% for criteria pointing towards a fall As for combined criteria in favor of a blow, the assumption was accurate in all cases (100%)
TL;DR: The results indicate that thermostable DNA polymerases have different susceptibility to bone‐derived PCR inhibitors, and that those most often used in forensic laboratories may not be optimal when working with DNA from skeletal remains.
Abstract: Amplification of DNA from aged or degraded skeletal remains can be a challenging task, in part due to naturally occurring inhibitors of the polymerase chain reaction. PCR inhibitors may act by inactivating a polymerase itself, or compete with or bind other reaction components, although various polymerases may be differentially susceptible to such insult. In this study, ten thermostable polymerases from six bacterial species were examined for their ability to amplify DNA in the presence of bone-derived or individual PCR inhibitors. Two polymerases, one from Thermus aquaticus and one from Thermus thermophilus, showed lower susceptibility to inhibition from bone, while polymerases from Thermus flavus were highly susceptible. Addition of bovine serum albumin improved the activity of most of the enzymes. Taken together, the results indicate that thermostable DNA polymerases have different susceptibility to bone-derived PCR inhibitors, and that those most often used in forensic laboratories may not be optimal when working with DNA from skeletal remains.
TL;DR: The experimental results from the 57 human bone sections and 12 molar teeth determined that the growth of hydroxylapatite crystallites is a direct and predictable function of the applied temperature, which follows a nonlinear logistic relationship.
Abstract: In view of the difficulties in extracting quantitative information from burned bone, we suggest a new and accurate method of determining the temperature and duration of burning of human remains in forensic contexts Application of the powder X-ray diffraction approach to a sample of human bone and teeth allowed their microstructural behavior, as a function of temperature (200-1000 degrees C) and duration of burning (0, 18, 36, and 60 min), to be predicted The experimental results from the 57 human bone sections and 12 molar teeth determined that the growth of hydroxylapatite crystallites is a direct and predictable function of the applied temperature, which follows a nonlinear logistic relationship This will allow the forensic investigator to acquire useful information about the equilibrium temperature brought about by the burning process and to suggest a reasonable duration of fire exposure
TL;DR: The fast multiplex PCR approach has the potential to reduce process time and cost for STR analysis and enables development of a fully integrated microfluidic forensic DNA analysis system.
Abstract: The time required for short tandem repeat (STR) amplification is determined by the temperature ramp rates of the thermal cycler,the components of the reaction mix, and the properties of the reaction vessel. Multiplex amplifications in microfluidic biochip-based and conventionaltube-based thermal cyclers have been demonstrated in 17.3 and 19 min, respectively. Optimized 28-cycle amplification protocols generated alleleswith signal strengths above calling thresholds, heterozygous peak height ratios of greater than 0.65, and incomplete nontemplate nucleotide additionand stutter of less than 15%. Full CODIS-compatible profiles were generated using the Profiler Plus ID, COfiler and Identifiler primer sets. PCR per-formance over a wide range of DNA template levels from 0.006 to 4 ng was characterized by separation and detection on a microfluidic electropho-resis system, Genebench-FXTM. The fast multiplex PCR approach has the potential to reduce process time and cost for STR analysis and enablesdevelopment of a fully integrated microfluidic forensic DNA analysis system
TL;DR: The effects of amphetamines were examined in cases reported to the Victorian coroner from 2001 to 2005 to determine if death can occur from the use of amphetamine‐class drugs alone to find no correlation between blood concentration of drug and outcome.
Abstract: In the present study, the effects of amphetamine-class drugs were examined in cases reported to the Victorian coroner from 2001 to 2005 to determine if death can occur from the use of amphetamine-class drugs alone. A total of 169 cases were reviewed where a forensic autopsy detected amphetamine(s) in the blood. Pathology, toxicology, and police reports were analyzed in all cases to ascertain the involvement of amphetamine-class drugs in these deaths. In Victoria, methamphetamine (MA) is the principal abused amphetamine-class followed by methylenedioxymethamphetamine (MDMA). There were six cases in which a cerebral hemorrhage caused death and three cases in which serotonin syndrome was established as being caused by the interaction of MDMA and moclobemide. There were 19 cases in which long-term use of amphetamines was associated with heart disease. There were three cases where amphetamine-class drugs alone were regarded as the cause of death, of which two cases exhibited high levels of MDMA and lesser amounts of MA and/or amphetamine. There were no cases in which significant natural disease was absent and death was regarded as caused by the use of MA. There was no correlation between blood concentration of drug and outcome.
TL;DR: Higher capillary electrophoresis injection settings were used to efficiently improve incomplete STR profiles generated from low‐level DNA samples under standard polymerase chain reaction (PCR) conditions, and an improved profile of the minor component was obtained.
Abstract: Evidentiary traces may contain low quantities of DNA, and regularly incomplete short tandem repeat (STR) profiles are obtained. In this study, higher capillary electrophoresis injection settings were used to efficiently improve incomplete STR profiles generated from low-level DNA samples under standard polymerase chain reaction (PCR) conditions. The method involves capillary electrophoresis with higher injection voltage and extended injection time. STR peak heights increased six-fold. Inherent to the analysis of low-level DNA samples, we observed stochastic amplification artifacts, mainly in the form of allele dropout and heterozygous peak imbalance. Increased stutter ratios and allele drop-in were rarely seen. Upon STR typing of 10:1 admixed samples, the profile of the major component did not become overloaded when using higher injection settings as was observed upon elevated cycling. Thereby an improved profile of the minor component was obtained. For low-level DNA casework samples, we adhere to independent replication of the PCR amplification and boosted capillary electrophoresis.