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The Creation of an Assessment Tool for the Analysis of Two Forms of Heat Damage in Animal Hair
Abstract
Animal cruelty cases can involve a variety of mistreatments to domestic animals. A common source of abuse is the use of heat sources, such as ovens, hot surfaces and microwaves. Analysis of damage to skin by a veterinarian is a key aspect of these investigations but additional information can be provided by observing the hair of the animal, including heat source type and exposure time. This study developed an objective grading system for the analysis of heat damage in hairs which can be used to quantify different damage characteristics including bubbling, discolouration, expansion of hair, fractures, changes to the medulla and scales and scale removal/melting. This grading scheme was applied to the investigation of dog (Canis familiaris) skin samples with full pelage and loose hairs exposed to microwaves and a heated environment in order to identify any distinguishing damage characteristics from the two different heated environments. Samples were exposed to a furnace for 1 minute at different temperature ranges (50- 350°C with 50°C intervals) and also a microwave at maximum power for different time periods (15, 30, 45, 60, 120, 180, 240 and 300 seconds). Hairs were extracted for examination using high powered light microscopy and scanning electron microscopy. Overall, it can be determined that the type of damage observed is influenced by the nature of heat applied and the context and substrate in which the hair is situated at the time of exposure. Using Principal Component Analysis (PCA) it was concluded that as temperature increases in a furnace so does the severity of each of the damage characteristics observed. It can be noted that with furnace exposure, any one of the characteristics could be used to indicate the temperature to which it has been exposed. For furnace exposed samples there was no significant difference between loose or embedded hairs. PCA analysis determined that there are two independent forms of damage that occur when hairs are exposed to microwave radiation, these are: increased bubbling and discolouration in the root and increased bubbling and discolouration of the shaft and tip. Exposure time is correlated with both the root and shaft/tip observations. The results indicated some clear distinctions between heat source and exposure useful for the objective interpretation of such evidence. This standardised approach for the observation of heat damage characteristics in animal hair provides investigators with a tool to differentiate between methods of abuse, providing a greater understanding of the crime committed.
Veterinary forensics is becoming increasingly important in the acquisition of evidence in cases of animal cruelty, unlawful killing, violation of wildlife law and medical malpractice. However, although forensic veterinary necropsy is one of the main techniques for gathering information about actions that have resulted in the unlawful killing of an animal, forensic necropsy of exhumed remains is rarely performed. We hypothesized that necropsy of exhumed animals can provide valuable information for the elucidation of cause of death. Hence, the present study aimed to describe the pathological changes observed in the necropsies of eight exhumed companion animals and to determine the frequencies of causes of death and diagnoses. This retrospective and prospective study was performed during the period 2008-2019. The causes of death of six of the eight disinterred animals were attributed to neurogenic shock (37.5 %), respiratory failure (25 %) and hypovolemic shock (12.5 %), with 50 % of necropsies providing conclusive diagnoses of physical/mechanical lesions and 25 % of infectious disease. The deaths of two animals could not be elucidated because of the advanced state of putrefaction. Ancillary testing comprised computed tomography (50 %), radiography (25 %), immunohistochemistry together with polymerase chain reaction/sequencing (12.5 %) and toxicology (12.5 %). The results support our original hypothesis since it was possible to observe macroscopic alterations that disclosed new information about the events connected with the demise of 100 % of the animals and to achieve irrefutable conclusions about the circumstances of death in 75 % of the studied cases.
Principal component analysis (PCA) is very useful for data exploration owing to its unsupervised nature; and has been proven to be a powerful multivariate exploratory tool for processing and interpreting high-dimensional data in many fields such as engineering, physical and biological sciences. In particular, PCA has been applied in various forensic problems to provide either a direct or an indirect solution. Despite the fact that improved variants of the classical PCA are consistently described in the literature, this review concerned only with the classical PCA in view of its overwhelming popularity. This review aims to summarize the application strategy of PCA in solving varying forensic problems. In total, 20 PCA application strategies have been derived from over 80 forensic studies published since 2017. The goal of this paper is to shed light on the versatility and capability of PCA in processing high-dimensional data in general and specifically on its potential in forensic studies. Hence, this work is also relevant to other research communities interested in unravelling latent structure from high-dimensional data.
Introduction and background:
Cosmetic procedures for hair, such as bleaching, dyeing, and straightening, are commonly used around the world. It has been suggested that excessive use of such procedures can cause damage to the hair shaft. We aimed to assess hair shaft changes using scanning electron microscopy (SEM) in female volunteers who frequently use hair treatment procedures such as bleaching, dyeing, or straightening.
Methods:
A cross-sectional, controlled study in a sample of 25 female volunteers (19 study group and 6 controls) in the age group of 18-45 years. The study group was composed of volunteers who regularly used different cosmetic hair treatment procedures such as bleaching, dyeing, and straightening (any one of these or a combination). The control group had never used any specific hair treatment procedure. The hair shaft damage as seen on SEM was assessed using a standardized scoring system and compared among the two groups statistically. The hair shafts were also examined clinically and with light microscopy.
Results:
No significant differences were seen between the test and control groups with regard to normal clinical examination and light microscopy findings. A higher degree of hair shaft damage was evident under SEM in the study group as compared to the control group. This difference was statistically significant.
Conclusions:
Regular use of procedures such as bleaching, dyeing, or straightening can lead to subtle changes in the hair shaft which can be detected early by SEM.
Significant numbers of institutions are carrying out fingermark based research, yet there appears to be little inter-institution consistency in the approaches used to assess the quality of the samples produced. Inter institution consistency in quality assessment would lead to inevitable benefits in collaborating research projects, given that data from multiple projects may be combined, or compared. In order for such quality assessment schemes to be effectively used across multiple institutions, proficiency in using such approaches should be identified to ensure parity. Intra-institution controls on fingermark quality assessment are likely to help manage variations between researchers from the same institution and/or project(s). Proficiency testing (PT) is a popular means of comparing and monitoring the competency of individuals, whilst also assessing the validity of data and conclusions. This project aimed to develop a proficiency testing scheme for the assessment of fingermark quality for researchers. A grading system was developed to assess the quality of fingermarks generated within research projects. A large collection of test fingermark samples were created controlling variables such as force, fingermark composition and surface type. An ‘inter-laboratory testing scheme’ design was used for the proficiency test and established fingermark researchers participated in the project to produce known values for 6 chosen test samples for round one of the testing scheme, described in this paper. Second year BSc (Hons) Forensic Science and Forensic Investigation student participants from the host institution completed the proficiency test as part of a fingermark practical. Results indicated that student participants involved in this project were not able to demonstrate a satisfactory level of proficiency of fingermark quality assessment using this grading system, which was attributed to their relative experience in assessing the quality of fingermarks compared to ‘experts’ in fingermark analysis. Results have highlighted considerations for future grading systems, and additional training requirements of users.
The role of the veterinary forensic pathologist in the investigation of animal abuse or neglect can go beyond documenting the condition of animals presented as evidence. Although animal cruelty is a moral concern and a crime in itself, law enforcement response to such crimes is often enhanced by the recognition that crimes against animals can be both indicators of other ongoing crimes against people and predictors of the potential for interpersonal violence. An understanding of common motives underlying animal cruelty can aid the pathologist in asking appropriate questions. The authors review the forms of pathology evidence commonly seen in various presentations of animal cruelty. Understanding these forms of evidence can help the pathologist describe findings that can be significant for assessing the potential risks the alleged perpetrator may pose to other animals and humans.
The performances and properties of the fine hairs from the coats of several domestic and wild mammals, namely the "speciality animal fibres" used for manufacturing high quality, luxury textiles, are influenced by the domes-tication process, heritability, hybridisation, nutrition, and life environment. In this work, the fibre morphology and cell structures of fibres from wild, domestic and crossbred goats were studied, with the aim of investigating the relationships with the thermal behaviour of the crystalline fraction of the fibres. Scanning Electron Microscopy investigation confirmed that exposure to thermal excursions and nutri-tional stresses lead to finer hair, associated with lower rate of growth, yielding strong orientation and elongation of the cuticle cells in the direction of the fibre axis. Transmitted Light Microscopy and Differential Scanning Calorimetry revealed specie-specific differences in the internal structure of the fibre cortex, probably related also to moisture during the process of hair keratinisation.
The relation between childhood cruelty toward animals and interpersonal aggression has long been of interest to developmental psychology, psychiatry, and related disciplines but the empirical study of this relation is relatively recent. This review highlights existing quantitative and qualitative research on childhood animal cruelty, organized according to four areas: (1) the relation between childhood cruelty to animals and concurrent and later antisocial behavior; (2) the significance of cruelty to animals as a specific symptom in the DSM-III-R classification Conduct Disorder; (3) the implication of cruelty to animals in various forms of family and community violence, including child physical and sexual abuse and wife battering; and (4) suggestions for research in the areas of definition, prevention, and intervention.
A method has been developed for the direct sequencing of hypervariable region 1 (HV1) of domestic dog (Canis familiaris) and wolf (Canis lupus) mitochondrial DNA (mtDNA) using single hairs as template. The method uses a robotic work-station and an automated sequencer to allow for robust routine analysis. A population data base was created in order to investigate the forensic and population-genetic informativeness of domestic dog HV1. Sequence variation, partitioning of dog breeds among sequence variants and phylogenetic relations between the variants were determined. Samples from 102 domestic dogs of 52 different breeds and two captive wolves were analyzed. Nineteen dog-sequence variants were found and the frequencies of the variants ranged from 1 to 21%. The calculated discrimination power of the region, i.e., the exclusion capacity, implied that nine out of ten disputed individuals can be excluded by this analysis. The sequence variants were found to cluster into four phylogenetic groups.
Despite recent advances in DNA technology, fingermark evidence remains a fundamental method of ascertaining an individual's identity. Latent fingermarks are the commonest type of fingermark encountered at crime scenes. The Fingermark Visualisation Manual provides crime scene practitioner's with sequential information regarding which enhancement processes are best suited for a range of deposition surfaces (Bandey et al., 2014) [1]. However, there are still many surfaces, such as painted walls where more knowledge is required regarding which development techniques provide optimum results. In this study, four paint types were tested (matt, silk, bathroom and eggshell). Fingermarks were deposited on painted simulated walls and aged for 1 day, 1 week and 1 month. Fingermarks were developed by three processes highlighted as the most frequently used by practitioners (magnetic granular powder, magneta flake powder and ninhydrin). The results showed that overall black magnetic granular powder outperformed both magneta flake powder and ninhydrin on all paint types. This contradicts current UK guidelines for enhancement of fingermarks on matt painted walls, as black magnetic granular powder is not a recommended process at present. SEM and SEM-EDX analysis showed distinct differences between matt paint and the three non-matt paints tested, which provides an explanation for the results obtained.
Due to inadequacies in historical hair examinations, the use and perceived value of microscopic hair evidence has reduced. Many reports have heavily criticised the use of pattern-based evidence including hair evidence as being unreliable, with police forces focussing on more individualising evidence. Hair evidence has been utilised in casework for many years due to its ability to transfer easily between individuals and crime scenes. Hair evidence can provide important information in criminal investigations, and in certain circumstances, aid in the identification of an individual, along with providing information to aid in the reconstruction of a crime scene. It has become apparent in recent studies, such as the 2012 FBI review, that hair evidence has been inappropriately utilised in case work and this, along with a preference for more discriminating methods such as DNA profiling, has led to both a lack of confidence in and reduction of use of hair evidence. The need for more standardised and objective methods is required along with improved methods for interpreting hair evidence. Since these reports, there has been no study investigating how these have affected the perceptions of hair evidence by forensic hair examiners or that has investigated what methods are being utilised to create a robust, objective and reliable interpretation of this evidence. This study aimed to assess the current similarities and differences in microscopic hair examinations and perceptions of its evidential value between countries, with a focus on the analysis and interpretation methods used by case work examiners and researchers.
This study will discuss the findings of a survey and interviews completed by hair examiners. Previous surveys have been conducted by Aitken & Robertson (1986) and Murphy (2013), however the current international status of microscopic hair examinations is unknown.
This study gathered responses across 9 countries. From this, it was identified that the microscopic examination of hair evidence is still valued highly by those practicing it. The amount of cases that an examiner has worked on that involve the examination of microscopic hair evidence is correlated to the perceived evidential value of hair evidence and to the value of morphological characteristics of hair. There are inconsistencies between the approaches used in interpreting this type of evidence. Subsequently, this study has generated an international understanding of the current status of hair examinations which was not previously known from an operational perspective.
Veterinary forensics is rapidly emerging as a distinct branch of veterinary medicine, especially because of increasing mindfulness about animal cruelty, and of the link between acts of cruelty to animals and violence toward humans. Nevertheless, the application of forensic sciences in veterinary cases lags behind its application in medical cases. Although gaps persist in veterinarians' knowledge of forensics and in how to apply this field to medicolegal cases involving animals, continued research and publication in veterinary forensics are rapidly developing the evidence base in this area. Additionally, educational opportunities in veterinary forensics are also increasing at both undergraduate and postgraduate levels. Together, these changes will continue to improve veterinarians' abilities to investigate cases involving animals. To further strengthen these investigations, veterinarians should also collaborate with the appropriate experts in different disciplines of forensic science.
Various keratin fibers, particularly human hairs, were investigated by transmission electron microscopy, TEM, solid-state 1HNMR and Transient Electro-Thermal Technique, TET. The results converge to suggest that the matrix of keratin fiber cortex, far from being amorphous, has a well-defined nano-scale grainy structure, the size of these grains being around 2 - 4 nm. The size of the grains appears to strongly depend on the chemical treatment of the fiber, on the temperature and on the relative humidity of the environment, as well as on the physiological factors at the level of fiber production in follicle. By suggesting an organization at the nano-scale of the protein chains in these grains, likely to be Keratin Associated Proteins, the results challenge the view of matrix as a homogeneous glassy material. Moreover, they indicate the potential of further investigating the purpose of this structure that appears to reflect not only chemical treatments of keratins but also biological processes at the level of the follicle.
Several studies have reported a connection between animal abuse and interpersonal violence. The importance of veterinarians in recognizing and intervening in the cycle of violence has been debated in different articles. This review outlines the findings about this connection around the world and describes the role veterinarians play in this field. We looked up electronic databases and analyzed articles published between 1960 and 2016. Publications were classified into three categories: area of publication, topic of the study and continent where the study had been conducted. Out of the 96 articles included, 76 (79.2%) were from North America. None were from South America or Africa. Ninety-four articles (97.9%) found some association between animal abuse and violence against people. The rates of co-occurrence between domestic violence and animal abuse reported varied between 25% and 86%. Furthermore, children who were abused, exposed to domestic violence, or animal abuse were at risk of developing criminal behavior. Veterinarians play an important role in public health and animal welfare. Yet, only seven articles (7.3%) were published in the field of veterinary medicine. Studies report that between 42.8% and 86% of veterinarians know about the “Link”. However, most veterinarians not being trained to intervene in cases of animal abuse and human violence. This emphasizes the importance of educating veterinarians about this topic and their participation in this area.
Scannig electron microscopy (SEM) can be applied to investigate hair shafts, extracted hair roots, hair follicles in tissue slices and hair follicles on the interface of the separated epidermis. The present investigation has been performed to study the influence of external damage to the hair shaft of scalp hair. In particular, an attempt has been made to classify the morphologic alterations of the hair shaft in relation to the grade and the type of the damage.
We examined rates of animal abuse in pet-owning families experiencing intimate partner violence (IPV). We also examined whether higher levels of IPV (as measured by subscales from the Conflict Tactics Scales) predicted increased risk for partner-perpetrated animal abuse. Our sample included 291 mother-child dyads, where the mothers sought services from domestic violence agencies. Nearly half the sample is comprised of Mexican immigrants. Mothers reported that 11.7% of partners threatened to harm a pet and 26.1% actually harmed a pet, the latter of which represents a lower rate than in similar studies. When examining animal abuse by "Hispanic status," follow-up analyses revealed significant omnibus differences between groups, in that non-Hispanic U.S.-born partners (mostly White) displayed higher rates of harming pets (41%) than either U.S.-born or Mexican-born Hispanic groups (27% and 12.5%, respectively). Differences in rates for only threatening (but not harming) pets were not significant, possibly due to a small number of partners (n = 32) in this group. When examining whether partners' IPV predicted only threatening to harm pets, no IPV subscale variables (Physical Assault, Psychological Aggression, Injury, or Sexual Coercion) were significant after controlling for income, education, and Hispanic status. When examining actual harm to pets, more Psychological Aggression and less Physical Assault significantly predicted slightly higher risk of harm. However, Mexican-born partners had nearly 4 times lower risk of harming a pet. Overall, these results suggest that Hispanic men who are perpetrators of IPV are less likely to harm pets than non-Hispanic perpetrators of IPV, particularly if Mexican-born. Considering that the United States has a significant proportion of Mexican immigrants, it may be worthwhile to explore the topics of IPV and animal abuse within this group.
Hairs from cats and dogs may be extremely important when used as evidence in the investigation of certain crimes and offenses. Certain parameters such as transfer and persistence are likely to be very similar to those encountered with fibers. These two parameters have been examined for dog and cat hair. The results confirm that hairs cling easily to various surfaces and that they are transferred in large numbers. It is almost impossible to enter a house where a domestic animal lives without being contaminated by its hair.
Due to their close association with man, dog hairs are frequently recovered from exhibits submitted to the forensic laboratory. Easily shed and exchanged, they could serve as a source of associative evidence if it could be established that different dogs of the same breed possess hair with sufficient variation of microscopic characteristics to permit some degree of individualization. Known dog hair samples were obtained from 25 pure bred German Shepherds who shared common lineage. Questioned hairs selected in the examiner's absence were compared macroscopically and microscopically to the known samples. Six of fifteen questioned hairs were correctly assigned to their sample of origin. No incorrect inclusions (Type II errors) occurred. The results of this preliminary study indicate that pure bred German Shepherd dogs possess some types of hair with sufficient variation of microscopic characteristics to permit some degree of individualization.
Evidence from an arson case was submitted for forensic analysis. It required the examination of the microscopic characteristics in burn t human hair. Burnt hairs are expected to exhibit a color change, expansion, and a bubbled appearance (1, 2) . However, a literature search failed to yield definite statements regarding at what temperatures these changes occur with respect to human hair encountered in forensic casework and whether these temperatures are within the range of heated hairstyling tools. Human head hairs were placed within a furnace heated to 100-400 °C. Hairs were examined before and after heat exp osure to determine at what temperatures color changes, expansion, and bubbling occur without a flame. Changes to the hairs were documented using photomicrography. Discoloration and bubbling were observed in specific circumstances at temperatures as low as 190 °C, which is within the operating range of some heat styling tools.
The extra-fine, soft and warm fibres used by the textile industry for manufacturing high-quality, luxury textiles are obtained from the undercoat hair of several domestic mammals of the genera Capra, Bos, Camelus, and Lama. The demand for ‘speciality fibres’ by the fashion world represents an important opportunity for livelihoods, on condition that conservation of the wild species is preserved. Large scale trade of hair from wild goats hunted for meat or trophy and hybridisation of wild (Capra ibex) and domestic (Capra hircus) goats or wild Vicuna (Lama vicugna) and domestic Alpaca (Lama pacos), with the aim of improving fibre fineness and yield, would involve a risk of genetic pollution and would severely threaten conservation and biodiversity. This work describes fibre morphology and cell structure of fine fibres from the most important wild and domestic fibre producing species with the aim of enhancing traits for identification purposes. Microscopy investigation shows that exposure to thermal and nutritional stresses in the wild, lead to finer hair associated with lower rate of growth, yielding orientation and elongation of the cuticle cells. Differential scanning calorimetry reveals specie-specific differences in the internal structure of the fibre cortex, probably related to the process of hair keratinisation.
Recent studies have offered compelling evidence supporting a relationship between childhood cruelty to animals and later violence against humans. This study investigated whether violent offenders were significantly more likely than nonviolent offenders to have abused animals of various types during childhood. Interviews were conducted with 45 violent and 45 nonviolent offenders incarcerated in a maximum-security prison and randomly selected for this study by institutional staff members. Two data collection instruments were used. The first extracted demographic and social history from the participants. The second was used to gather information regarding cruelty to animals as categorized into four types (wild, farm, pet, and stray). Results indicated that a statistically significant relationship existed between childhood cruelty to animals and later violence against humans. Furthermore, the study found, consistent with prior research, that violent offenders were significantly more likely than nonviolent offenders to have committed acts of cruelty toward pet animals as children.
Author Institution: Ohio Agricultural Experiment Station, Wooster
This paper reports on a small study which investigates the connection between domestic violence and non-accidental injury in animals in the Republic of Ireland. This found that many women reported witnessing one or more forms of abuse, or threats of abuse, of their pets. Most women considered that a place to accommodate pets would have made their decision to leave the family home easier. Four women disclosed that lack of such a service and concern for the welfare of their companion animals caused them to remain in their abusive relationships for longer than they felt appropriate. The majority of women felt unable to talk to anyone about their fears for their pets' welfare and there is no service which can provide temporary accommodation for women's pets while they are in a refuge. These findings support those found elsewhere in larger studies in the US and UK, and demonstrate a high incidence of animal abuse in households where there is reported domestic violence. The implications for social work education and practice of the issue of violence against women are discussed.
This study investigated the persistence of animal hairs (cat and dog) on garments by examining variables such as different types of animal hair, different fabric types and differences in fabric features. Hair/fabric interactions were found to be far more complex than previous research had indicated. Three factors were identified that appeared to account for the majority of the differences in persistence. These factors were fibre type, yarn or knit tightness and the presence or absence of surface fibres on the recipient fabric. For example, the fabric type and the structure of the garment were shown to be integral to the mechanism of hair persistence. Structure in terms of knit variation or yarn tightness and fabric type such as wool with surface fibres appeared to exert the most influence on the retention of the animal hair on a particular garment. Wool garments had a much shallower initial decay where 82% of the hairs remained after 30 minutes, as opposed to polyester garments that exhibited a deep initial decay where only 25% of the hairs remained after 30 minutes. The initial loss – between 0–30 minutes – of hairs from all fabrics is much more rapid than the loss of hairs over all other times. Fabrics such as cotton and polyester appear much less retentive than wool and acrylic.
Although it has been generally accepted within the forensic hair community that decompositional changes in the form of an identifiable banding pattern can occur in the root area of hairs after death, little detailed information with regard to this phenomenon is known (e.g., rates at which this occurs and conditions that cause this banding). Hairs were collected daily from bodies placed in water, an air-conditioned environment, an enclosed vehicle, on the surface of the ground, and buried at the University of Tennessee Forensic Anthropology Center. The hairs were examined microscopically and the level of change documented for each environment. The onset of the banding was observed to have been delayed in water, air-conditioning, and cold weather and was hastened by warm weather and within the vehicle. This study provides validation that decomposition does produce varying effects on hair at the proximal portion of a hair root, including a dark band.
Currently there is no standard way of carrying out research into finger mark enhancement techniques. Individuals, groups or establishments tend to use different methodologies depending on a number of factors, especially finance and time. However, data published in the literature can be misleading to the forensic community if the data generated reflects research involving very few finger marks or if those finger marks have been deliberately doped with an unnatural balance of sweat or an unusual contaminant. This paper presents an experimental methodology which is intended to establish minimum standards for those carrying out finger mark enhancement research (at least within the United Kingdom) and bring some consistency to the process. It will aim to identify the many variables encountered when dealing with finger marks and suggest experimental methods to take these into account. It will also present the key stages of the progression of a process from a laboratory concept to a tool used on operational work.
Studies investigating the specific methods for committing nonhu-man animal cruelty have only begun to expose the complexities of this particular form of violence. This study used a sample of 261 male inmates surveyed at both medium-and maximum-secu-rity prisons. The study examined the influence of demographic attributes (race, education, and residence while growing up). It also examined situational factors (was the abuse committed alone, did abuser try to conceal the act, was abuser upset by the abuse, what was the perpetrator's age at initial animal cruelty, how fre-quent was the animal abuse?) and specific methods of animal cru-elty (shooting, drowning, hitting or kicking, choking, burning, sex). Regression analyses revealed that white inmates tended to shoot animals more frequently than did non-whites and were less likely to be upset or cover up their actions. Respondents who had sex with animals were more likely to have acted alone and to con-ceal their cruelty toward animals. However, we failed to find sup-port for a potential link between childhood and adolescent animal cruelty methods and later violence against humans.
The identification of animal hairs is generally recognised to be one of the more difficult types of examination with which forensic scientists have to deal. The main reason for this is the variation that can exist within a species and even between hairs from the same animal. A considerable amount of experience is therefore required before the identification of animal hairs can be carried out with confidence. However, cases involving animal hairs are infrequent and experience is not readily acquired through casework alone.
A method that provides objective data to complement the hair analysts' microscopic observations, which is non-destructive, would be of obvious benefit in the forensic examination of hairs. This paper reports on the use of objective colour measurement and image analysis techniques of auto-montaged images. Brown Caucasian telogen scalp hairs were chosen as a stern test of the utility of these approaches. The results show the value of using auto-montaged images and the potential for the use of objective numerical measures of colour and pigmentation to complement microscopic observations.
Human hairs experience damage and restoration processes consistently because of various external and internal factors. To analyze degrees of hair damage, morphological studies based on electron microscopy (EM), and biochemical studies based on protein and lipid analysis have been proposed and are widely used. Among them, morphological analysis through EM is a fundamental method in understanding the degree of damage and restoration. EM has been very useful in assessing extrinsic and intrinsic damage of hair and various pathological alopecias and also in estimating the efficacy of various kinds of products related to hair care. However, morphological studies have some limitations because they have been described using varying terms and subjective descriptions by different researchers. To establish an objective classification of damaged hair using uniform terms and standardizations. We analyzed over 2000 scanning electron microscopic and transmission electron microscopic findings of normal and of various kinds of damaged hairs to develop a standard grading system for the damaged hairs. After reviewing the results of the electron microscopic pictures, we proposed a standard grading system based on scanning electron microscope and transmission electron microscope. We developed and proposed an easy, objective, and useful standard grading system of damaged hairs.
Human hair is among the most common kind of evidence secured at crime scenes. Although DNA analysis through STR-typing is possible in principle, it is not very promising for telogenic hair or single hairs. For the mixed traces frequently found in practice, composed of different hair from an unknown number of individuals, mtDNA sequencing of each individual hair seems to be the only possible, even if technically elaborate, solution. If it were possible to pool all hair belonging to an individual prior to DNA analysis, then this effort could not only be reduced, but the number of hair for an STR-approach could also be increased. Although it is possible to examine hair microscopically, this method must be considered unsuitable for pooling, since the results depend strongly on examiner experience, and the hair cannot always be correctly attributed to an individual. The goal of this study was to develop an objective non-DNA-contaminative pooling method for hair. To this end, the efficacy of spectral imaging as a method of obtaining information--beyond that obtained from a purely microscopic and morphological approach--for the identification of individuals was investigated. Three hairs each from 25 test persons (female: 18; male: 7) were examined with a SpectraCube-System and a light microscope. Six spectra were calculated for each hair, and the hairs from each individual were not only compared to each other, but also to those of the other individuals. From a forensic vantage, the examination showed, in particular, that individuals, whose hair could not be distinguished on the basis of morphology, could also not be accurately distinguished with the SpectraCube. The intra-individual differences were, in part, greater than the inter-individual differences. Altogether, the study shows that a person's hair color, as perceived, is composed of many naturally different, individual colors.
While reflective spectrophotometry is an established method for measuring macroscopic hair colour, it can be cumbersome to use on a large number of individuals and not all reflective spectrophotometry instruments are easily portable. This study investigates the use of digital photographs to measure hair colour and compares its use to reflective spectrophotometry. An understanding of the accuracy of colour determination by these methods is of relevance when undertaking specific investigations, such as those on the genetics of hair colour. Measurements of hair colour may also be of assistance in cases where a photograph is the only evidence of hair colour available (e.g. surveillance). Using the CIE L(*)a(*)b(*) colour space, the hair colour of 134 individuals of European ancestry was measured by both reflective spectrophotometry and by digital image analysis (in V++). A moderate correlation was found along all three colour axes, with Pearson correlation coefficients of 0.625, 0.593 and 0.513 for L(*), a(*) and b(*) respectively (p-values=0.000), with means being significantly overestimated by digital image analysis for all three colour components (by an average of 33.42, 3.38 and 8.00 for L(*), a(*) and b(*) respectively). When using digital image data to group individuals into clusters previously determined by reflective spectrophotometric analysis using a discriminant analysis, individuals were classified into the correct clusters 85.8% of the time when there were two clusters. The percentage of cases correctly classified decreases as the number of clusters increases. It is concluded that, although more convenient, hair colour measurement from digital images has limited use in situations requiring accurate and consistent measurements.
The results of a comparative study of the head hair of man and a large number of nonhuman primates are presented. The metrical features of human head hair are not distinct enough from those of other primates to use micromeasurement as a sole means of hair identification. It is suggested that a broad range of techniques be employed in hair identification cases.
Four hundred and twenty hairs from 22 cats and 20 dogs have been examined by scanning electron microscopy and optical microscopy. Several characteristics of each hair were examined. Measurements of medullary fraction and width were used to devise a computer program to assist the operational scientist in deciding whether an unknown hair is more likely to have come from a cat than a dog or vice versa. The program enables the scientist to combine any subjective judgement he may have formed of the correct classification of the hair with the information derived from the measurements. The results of a trial on 20 unknown hairs are presented and discussed.
In order to investigate the nature of animal cruelty in childhood two groups of male psychiatric patients were compared: an Animal Cruelty Group and an Assaultive Group. Most in both groups showed other signs of aggression dyscontrol in childhood. Most in both groups were subjected to parental brutality. Emotional or physical unavailability of a father figure may be a common etiologic factor in childhood cruelty to animals. This may compare with the absence of a father figure noted by several investigators in boys who set fires.
A self-report questionnaire designed to assess abusive childhood environments and exposure to animal cruelty was administered to 314 inmates in a prisoner classification center. Although high rates of physical punishment characterized the entire sample, persons charged with violent, but nonhomicidal crimes reported more severely punitive childhood histories than those charged with homicidal crimes, sex offenses, and nonviolent offenses. Some exposure to animal cruelty was widespread in the sample, but there was no association between experiencing animal cruelty and the type of crime committed. Moreover, there were only modest associations between animal cruelty experiences and the aversive childhood histories of the subjects, as well as the subjects' reported use of physical and sexual coercion in dating and intimate relationships. To determine whether the high base rate of exposure to animal cruelty was unique to the incarcerated sample, a follow-up study was completed with university undergraduates. Widespread exposure to some animal cruelty was reported by undergraduates; there were modest associations between reporting animal cruelty and reporting punitive and acrimonious childhood histories. In general, the findings were consistent with the hypothesis that there is an association between punitive childhood histories and antisocial behavior but not consistent with the hypothesis that exposure to animal cruelty is importantly related to antisocial behavior or child maltreatment.
Only two types of human hair roots (proximal ends) derived from decomposing scalps are reported in the literature. The most common representation of the putrid root includes a postmortem dark root band in published photomicrographs. In this study, 22 cases were reviewed in which there was reliable time of death documentation from medical investigator reports. A review of these cases finds that the most common putrid hair proximal end change does not contain the postmortem root band. Four primary types of hair proximal end postmortem change were identified. This study finds no correlation of time of death with scalp hair proximal end decomposition. In addition two examples are presented that suggest that hair roots do not decompose after fresh removal from the scalp and exposure to the outside elements.
Records of 243 cases of non-accidental injury (NAI) in dogs, and 182 cases in cats, submitted by a sample of small animal practitioners in the UK, revealed a wide range of injuries. These included bruises, fractures, repetitive injuries, burns and scalds, stab and incised wounds, poisoning, asphyxiation and drowning (which showed remarkable similarities to NAI in children), as well as sexual abuse and injuries specifically caused by firearms. Traumatic skeletal injuries in the dogs were more commonly found in the anterior part of the skeleton, in comparison with those resulting from road traffic accidents. Young male dogs and young cats were particularly at risk of NAI. A moderately increased risk was identified in the Staffordshire bull terrier, cross-breed dogs and the domestic shorthaired cat, whereas the Labrador retriever showed a decreased risk. No single injury or group of injuries, when divorced from the circumstances surrounding a suspect case, could be considered to indicate, conclusively, NAI. Repetitive injuries, however, were highly suggestive of NAI.
This paper demonstrates the feasibility of the automation of forensic hair analysis and comparison task using neural network explanation systems (NNESs). Our system takes as input microscopic images of two hairs and produces a classification decision as to whether or not the hairs came from the same person. Hair images were captured using a NEXTDimension video board in a NEXTDimension color turbo computer, connected to a video camera. Image processing was done on an SGI indigo workstation. Each image is segmented into a number of pieces appropriate for classification of different features. A variety of image processing techniques are used to enhance this information. Use of wavelet analysis and the Haralick texture algorithm to pre-process data has allowed us to compress large amounts of data into smaller, yet representative data. Neural networks are then used for feature classification. Finally, statistical tests determine the degree of match between the resulting collection of hair feature vectors. An important issue in automation of any task in criminal investigations is the reliability and understandability of the resulting system. To address this concern, we have developed methods to facilitate explanation of neural network's behavior using a decision tree. The system was able to achieve a performance of 83% hair match accuracy, using 5 of the 21 morphological characteristics used by experts. This shows promise for the usefulness of a fuller scale system. While an automated system would not replace the expert, it would make the task easier by providing a means for pre-processing the large amount of data with which the expert must contend.
There has been debate in both the judicial and forensic fields concerning the admissibility and reliability of the so-called forensic comparison sciences such as handwriting, tool mark analyses, and hair analysis. In particular, there has been increasing controversy over the use and interpretation of hair comparison evidence and it has been held partly responsible for miscarriages of justice. There has also been a perceived devaluation of the worth of microscopic human hair analysis particularly since the advent of DNA profiling. This article will attempt to initiate discussion on the past, current and future role of forensic human hair analysis and comparison.
Obtaining palynological and other botanical evidence from murder victims is becoming part of routine mortuary protocol in the United Kingdom. Forensic pathologists are often keen to cooperate in the collection of classes of material that have, in the past, been considered to be of little importance in criminal investigation. Work over the last eight years has demonstrated the great value in scrutinising cadavers for the presence of plant material and/or soil stains. Macroscopic plant remains and palynomorphs (pollen, spores and other microscopic entities) retrieved from skin and hair have allowed the differentiation of murder scenes from places of eventual deposition. Furthermore, although the opportunity has not yet presented itself, obtaining palynological evidence from the hair of suspects is feasible. During an offence, the offender might have had physical contact with foliage or the ground. Pollen and spore assemblages picked up by hair during that activity might provide forensic evidence for contact. Brief details of some aspects of case histories are presented to demonstrate the value of sampling cadavers. One case has been through the courts while the other is ongoing and, therefore, cannot be identified.
Few researchers have investigated the potentially predictive power of childhood and adolescent animal cruelty methods as they are associated with subsequent interpersonal violence in adulthood. Based on a sample of 261 inmates at medium- and maximum-security prisons in a southern state, the present study examines the relationship between several retrospectively reported animal cruelty methods (drowned, hit or kicked, shot, choked, burned, and had sex) and violent criminal acts committed against humans (assault, rape, and murder). More than half of the sample reported they had shot animals, and almost half had either kicked or hit them. About one in five said they had choked animals, and about one in seven said they had either drowned, burned, or had sex with them. Regression analyses revealed that drowning and having sex with an animal was predictive of later interpersonal violence as adults.
A microscopical study of exotic animal hair: part 1
- Partin
Forensic species identification of elephant (Elephantidai) and Giraffe (Giraffidae) using light microscopy
- Yate
Battered pets and domestic violence: animal abuse reported by women experiencing intimate violence and by non-abused women
- Ascione
Misleading colour changes in hair that has been heated but not exposed to flame
- Ayres