Sex estimation in forensic anthropology: skull versus postcranial elements

When the pelvis is unavailable, the skull is widely considered the second best indicator of sex. The goals of this research are to provide an objective hierarchy of sexing effectiveness of cranial and postcranial elements and to test the widespread notion that the skull is superior to postcranial bones. We constructed both univariate and multivariate discriminant models using data from the Forensic Anthropology Data Bank. Discriminating effectiveness was assessed by cross-validated classification, and in the case of multivariate models, Mahalanobis D(2). The results clearly indicate that most postcranial elements outperform the skull in estimating sex. It is possible to correctly sex 88-90% of individuals with joint size, up to 94% with multivariate models of the postcranial bones. The best models for the cranium do not exceed 90%. We conclude that postcranial elements are to be preferred to the cranium for estimating sex when the pelvis is unavailable.     

Determination of sex by discriminant function analysis and stature by regression analysis: a lateral cephalometric study

Determination of sex and estimation of stature from the skeleton is vital to medicolegal investigations. In the present study, an attempt is made to determine sex and estimate stature of an individual using data derived from lateral cephalogram in Central Indian population. Skull is composed of hard tissue and is the best preserved part of skeleton after death, hence, in many cases it is the only available part for forensic examination. Lateral cephalogram is ideal for the skull examination as it gives details of various anatomical points in a single radiograph, also it easily provides architectural and morphological details of skull superstructures and intra-cranial details for comparisons. A discriminant function derived from 10 cephalometric variables provided 99% reliability in sex determination. The formulae obtained from regression analysis using the maximum length of skull showed very high degree of reliability for estimation of stature in males as well as females.     

Sexual dimorphism in the crania and mandibles of South African whites

Numerous studies have clearly demonstrated that skeletal characteristics vary by population. To date, there are no metric cranial criteria for South African whites. Therefore, the purpose of this study is to establish population specific standards for sex determination from the skull. A total of 12 standard cranial and five mandibular measurements were taken from 44 male and 47 female skeletons of known sex and race from the Pretoria and Dart collections. These were subjected to SPSS discriminant function analysis. Bizygomatic breadth was the most dimorphic dimension. Five functions were developed from the complete cranium, vault, face, mandible and bizygomatic breadth. Dimensions from the complete cranium provided the best accuracy. In the mandible, bigonial breadth was the most dimorphic of the measurements taken. Average accuracies ranged from 80% (bizygomatic breadth alone) to 86% (cranium). These accuracies are similar to those obtained by researchers on other groups (e.g., 84% in Japanese crania and about 86% in American whites and blacks). Diagnostic accuracy, however, is lower than that obtained from the South African femur and tibia.     

Metric assessment of race from the pelvis in South Africans

It is well known that there are measurable differences between whites and blacks in the size and proportions of skeletal components. There are also metric differences among populations within these racial phenotypes. The population specific quantification of this variation can be used to aid in the identification of racial affinity in the absence of a more racially definitive skeletal element like the skull. Therefore, the purpose of this research is to quantify these differences in the pelvis of South African whites and blacks. A sample of 400, ostensibly healthy known sex/race os coxae was examined. Skeletal material was obtained from the Pretoria and Dart collections. A series of 13 measurements were taken Data were subjected to SPSS stepwise and direct discriminant function analysis. Pubic length was chosen as best for discriminating between races for males and iliac breadth as best in females. Highest average accuracies (Function 1) were 88% for males (pubic length, greater sciatic notch posterior width, acetabulum diameter, total height) and 85% for females (pubic length, greater sciatic notch posterior width, acetabulum diameter, iliac breath). In conclusion, this research resulted in the development of standards of identification tailored to this population and unquestionably demonstrates that race differences in the skeleton are highly significant and must be considered in all skeletal analyses.     

Race,Plea, and Charge Reduction: An Assessment of Racial Disparities in the Plea Process

With the growing recognition of the salience of prosecutorial discretion, attention to biases in the earlier phases of case processing is increasing. Still, few studies have considered the influence of defendant race and race/sex within the plea process. The present study uses a sample of felony cases to assess the influence of race and race/sex on the mode of disposition, similarities and differences in the factors that predict the likelihood of a plea across race, and potential racial disparities in the plea value received pertaining to a charge reduction. The findings suggest that blacks, and black males in particular, are less likely to plea, and are expected to receive a lower value for their plea. Also, the factors that predict the likelihood of a plea are substantively different across race. Conditioning effects of race and sex are found in the likelihood of a plea and probabilities of a charge reduction.     

Victimization Rates, Exposure to Risk, and Fear of Crime

Studies of fear of crime repeatedly point to an apparent paradox: fear of crime and risk of victimization are related inversely among demographic groups (i.e., age, race, and sex groups). However, data from surveys of Chicago residents show that fear of crime is related positively to victimization rates once they are adjusted for exposure to risk. When demographic variables are included with the adjusted rates as predictors of fear of crime, age and sex effects persist. Even so the present findings indicate that fear of crime should not be interpreted as an irrational or unjustified response and that fear can be reduced by lowering victimization rates.     

Metacarpal sexual determination in a Spanish population

Anthropologists and forensic pathologist determine the sex of skeletons by analyzing quantitative and qualitative characters in the bone remains. Generally, the skull and os coxae are the elements most used, but they are not always preserved. In such cases, the investigator needs to have available other techniques based on different remains. The aim of the present work is to develop and describe discriminating functions for sex determination in a recent Spanish population using metacarpal morphology. A sample of bones corresponding to a contemporary Spanish population deposited at the Complutense University of Madrid (UCM) was analyzed. This sample comprised 697 metacarpals, corresponding to 79 adult individuals (37 men and 42 women). These allowed us to obtain 120 unifactorial discriminant functions. We selected the 10 equations, one for each metacarpal from both hands, that provided the best sexual discrimination. The correct sex classification rank progressed from 81%, for right (R) metacarpals IV and V, to 91%, for left (L) metacarpal II. The results suggest that metacarpals are structures that can be used for sex determination in paleoanthropological and forensic identifications.     

Sex diagnosis of Chinese skulls using multiple stepwise discriminant function analysis.

Sixty Chinese skulls (30 males and 30 females) from Liaoning Province of the People's Republic of China were used in this study. Forty-one variables on each skull were measured and one group of 14 and a second group of 5 variables were selected from all the variables by applying multiple stepwise regression on a computer. Discriminant equations for the 14 and 5 variables for sex diagnosis have been obtained and these variables are highly significant. The discriminant rate for the group of 5 variables resulted in accurate sex determination in 96.7% of cases. For the group of 14 variables there was 100% success rate.     

A sociolegal analysis of Canadian youth justice: The impact of offender's race on judicial decisions

There is evidence to suggest that even within ostensibly egalitarian systems of justice young offenders are, at least in part, socially selected. Police, court workers, lawyers, and judges make prejudgments of young offenders on the basis of extralegal as well as legal factors. This study examined the influence of extralegal variables, especially offender's race, on judicial outcomes including detention on arrest, plea, adjudication, and sentencing. While the principal focus was the effect of offender's race, the effects of other attributes including sex, age, family support, and counsel status were incorporated into the analysis to present a comprehensive explanatory model of justice.Loglinear/logit modelling techniques were employed to assess the simultaneous effects of social and legal variables. In summary, the data consistently supported the claim that at all levels of the justice process extralegal variables, most noticeably race, had a substantial systematic influence on judicial decisions, especially when seriousness of offense and criminal record were controlled. Most importantly, the study showed that the effects of race occured primarily in interaction with both legal and extralegal factors.     

Testing the validity of population-specific sex estimation equations: An evaluation based on talus and patella measurements

Sex estimation is essential for forensic scientists to identify human skeletal remains. However, the most sexually dimorphic elements like pelvis or skull are not always assessable. Osteometric analyses have proven useful in sex estimation, but also to be population specific. The main purpose of this study was to test the validity of contemporary Greek and Spanish discriminant functions for the talus and the patella, respectively, on a Swiss skeletal sample and to quantify the utility of the measurements as a novel approach in osteometric sex assessment.Four talus and three patella measurements on dry bone were obtained from 234 individuals of the modern cemetery SIMON Identified Skeletal Collection. The previously derived discriminant functions were applied, accuracies determined, the utility of the different measurements was assessed and new multivariable equations constructed.Accuracies varied between 67% and 86% for talus and 63% and 84% for patella, similar to those reported by the original studies. Multivariable equations should be preferred over equations based on single measurements and combining the most significant measurements rather than using several variables obtained the best possible accuracy. The new discriminant functions did not provide a substantial improvement to the original ones. The overall utility of talus and patella is limited, allowing sex estimation with sufficient certainty only in a small proportion of individuals.Discriminant functions developed in contemporary Greek or Spanish populations are in principle applicable also to Swiss contemporary populations. We recommend that at present existent studies of this type should be validated and tested rather than developing new formulas.     

Demeanor,sex, and race in police processing

Recent increases in arrests of women have stimulated much controversy about the causes and extent of female crime and created much speculation about the differential treatment of female offenders by police officers. This article reports an empirical study of police processing of female offenders. During September–December 1978, 282 questionnaires were completed by police officers and detectives in a large, metropolitan area in a southeastern state. Each officer was asked to indicate a police decision in five hypothetical situations which varied by types of offense, race of the offender, sex of the offender, and demeanor of the offender. An analysis of the responses of the police officers indicates that decisions of police are not contingent on the sex and race of the offenders. The major variables in determining how police officers will respond are the nature of the offense and the manner in which the offender behaves when confronted by the officer.     

Application of 3-D computer graphics for facial reconstruction and comparison with sculpting techniques

Facial reconstruction has until now been carried out by the sculpting technique. This method involves building a face with clay or other suitable material on to a skull or its cast, taking into account appropriate facial thickness measurements together with information provided by anthropologists such as approximate age, sex, race and other individual idiosyncrasies. A method for facial reconstruction is presented using 3-D computer graphics and is compared with the manual technique. The computer method involves initially digitising a skull using a laser scanner and video camera interfaced to a computer. A face, from a data bank which has previously digitised facial surfaces, is then placed over the skull in the form of a mask and the skin thickness is altered to conform with the underlying skull. The advantage of the computer method is its speed and flexibility. We have shown that the computer method for reconstructing a face is feasible and furthermore has the advantage over the manual technique of speed and flexibility. Nevertheless, the technique is far from perfect. Further facial thickness data needs collecting and the method requires evaluation using both known control skulls and later unknown remains.     

Improving Sex Estimation from Crania Using a Novel Three‐dimensional Quantitative Method,,

This study utilizes an innovative 3D approach to discover metric variables that obtain the highest classification rates for sex estimation from the cranium. Models were constructed from 222 cranial CT scans of U.S. Whites from the Bass Donated Collection. These models were used to create a statistical bone atlas that captures the primary shape variation in the skull and facilitates rapid computer‐automated analyses. The bone atlas showed that important size‐related sex variables are bizygomatic breadth, maximum cranial length, cranial base length, and mastoid height. Shape‐related variables capture sex differences in the projection of the glabellar region, inclination of the frontal, and cranial base flexion. In addition, vault thickness is highly dimorphic, with females having on average thicker vaults in the frontal region, and males having thicker vaults in the occipital region. Cross‐validated linear discriminant analysis obtained >95% accuracy (97.5% with 11 variables and 95.5% with eight variables).     

Metropolitan forensic anthropology team (MFAT) case studies in identification: 3. Identification of John J. Sullivan, the missing journalist

Skeletal remains removed from an unmarked grave in El Salvador were intensively studied by a team of forensic science experts. Even though the skull, teeth, and several major bones were missing, a positive identification was made of the missing journalist. This was contrary to reports submitted to the State Department by Salvadorian officials. All of the methods used in this investigation, which includes a new method for simultaneously assessing sex and race by discriminant function analysis that was tested by application, are fully described. The international background of this case and information regarding the cause of death is discussed.     

Arson for revenge: The role of environmental situation,age, sex,and race

Research on arson and its many motivations continues to be absent from the criminological literature. Although some authorities cite revenge or retaliation as the primary motive for arson in certain areas of our central cities, revenge arson has not been systematically addressed. The research presented here explores whether demographic variables (age, race, and sex) along with the environmental character of the offender's place of residence adequately determine the likelihood that offenders will commit arson for revenge. The analysis not only indicates that important age and racial differences affect the likelihood that individuals will use fire as a weapon of retaliation but also reveals that the environmental situation or character of the offender's place of residence appears to condition the relationship of both age and race with retaliation.     

The Impact of Victim Demographics on Case Outcomes in Delinquency Proceedings: An Empirical Test

While the impact of the defendant's sex and race on processing decisions is well researched, less is known about the impact of the victim's sex and race on juvenile court decision making. Using data from the juvenile court in St. Louis, Missouri, this study explores direct and interactive effects of the victim's sex and race on outcome decisions for juvenile offenders. Findings suggest that legal differences account for most of the observed differences in detention, commitment and adjudication among the sample studied.     

Using the National Incident-Based Reporting System (NIBRS) to Test Estimates of Arrestee and Offender Characteristics

National-Incident Based Reporting System (NIBRS) information for 1993 iscompared with two other sets of homicide data to assess the acuracy ofprocedures for estimating age-, sex-, and race-specific arrest counts fromtraditional Uniform Crime Report (UCR) data. The simultaneous age, race, andsex characteristics of offenders provided in the NIBRS arrest and offender segmentsare compared with estimates of the same characteristics derived from summaryUCR arrest data. The results suggest that using UCR marginal totals toestimate arrest counts by race and sex produces reasonably accurateestimates of the number of black and nonblack male arrests for murder andother offenses. Estimates of arrests of females by race and sex are lessaccurate, probably because of the relatively small number of arrests ofwomen and girls. Estimating male arrest counts for specific age groups alsoproduces reasonably accurate estimates. The results suggest that previousresearch employing such estimates may have been misleading in the estimatesof female arrests by race but accurate in the estimates of male arrests byrace. Although the use of summary UCR-based estimates in futurecross-sectional research will become increasingly unnecessary as the NIBRSreplaces the current UCR program, time series research designs on arrest andcrime trends will continue to require estimates.     

Recent human sexual dimorphism study using cephalometric plots on lateral teleradiography and discriminant function analysis

Abstract:  The examination of skull sexual dimorphism has been the subject of numerous morphologic and craniometric studies, but the disadvantage of these studies is that they are dependent on the experience of the operator and involve subjectivity. In 1996, a team from Taiwan refined the methods enabling the sex of an individual to be determined using cephalometric plots made from lateral teleradiography. To validate their work using a European population, 114 dry skulls (59 men and 55 women) were examined. Cephalometric plots were made on lateral teleradiography with an orthodontic software and 18 cephalometric variables were analyzed. Sex was determined with 95.6% accuracy using the 18 variables discriminant function. A subset of eight variables was selected and could predict sex with the same accuracy. In conclusion, it can be said that skull-sexing methods using lateral teleradiography seem always suitable but the most indicative variables could differ relative to the ethnic population concerned.     

PERCEPTIONS OF THE WORK ENVIRONMENT AMONG CORRECTIONAL OFFICERS: DO RACE AND SEX MATTER?*

This article examines the relationship between race and sex and perceptions of the work environment among correctional officers. It addresses four central questions: (1) Are there race and sex differences among correctional officers in their perceptions of the work environment? (2) Do characteristics of the job and the institutions in which officers work account for these differences? (3) Do these differences attenuate over time? (4) Are there factors that mediate the relationship between race and sex and perceptions of the work environment? These issues are explored using data drawn from the correctional officer sub-sample (N= 2,979) of the 1992 administration of the Prison Social Climate Survey. Findings indicate that race and sex do play a role in shaping officers’ perceptions of the work environment, that these differences between groups are not completely accounted for by job or institutional characteristics and do not attenuate over time, and that there are factors that mediate the relationship between race and sex and workplace perceptions. Among minority male officers, greater efficacy in working with inmates appears to be an important factor in creating lower levels of job stress, while white female officers’ higher levels of overall job satisfaction are accounted for largely by a more positive evaluation of the quality of supervision.     

Sex determination by discriminant function analysis of lateral cranial form.

To sex the cranium, morphological features of cranial specimens were quantified with a personal computer that automatically measures distance and gradient for 39 craniometric points in the lateral contour line of the skull, which were digitized by a tablet digitizer connected to the computer. Specimens used for discriminant analysis were 50 male and 50 female adult Japanese skulls. The lateral contour showed sex differences in the nasal bone, supraorbital ridge, forehead and vertex. The nasal bone and supraorbital ridge were more developed in male contour line, and the forehead was more rounded in female contour line. But compared with the supraorbital ridge and forehead, the vertex had a wide variety of contour lines in both sexes. The vertex seemed to be less reliable as the indicator of sex. The sex differences were better reflected by gradient than distance. From variables of the gradient and distance showing significant sex differences, the discriminant function was derived and tested in 21 other specimens (13 male and 8 female skulls). The mean ratio of correct sexing of the human skull by the discriminant function was 86%.