Identifying the dead: methods utilized by the Pima County (Arizona) office of the medical examiner for undocumented border crossers: 2001-2006

The Pima County (Arizona) Office of the Medical Examiner has seen a dramatic rise over the past 6 years in the number of deaths related to the illegal crossing of our international border with Mexico. This rise in deaths is undoubtedly related to an increase in the number of foreign nationals who cross into the various Arizona jurisdictions that utilize the Pima County Medical Examiner to investigate their unnatural deaths. Because of the utterly dangerous nature of trekking across the Sonoran Desert, especially in the summer months, many of these unfortunate migrants succumb to the effects of heat-related illness and perish along the journey. The combined effects of a dry, hot environment and the remoteness of some of the trekking corridors can quickly render a deceased person unidentifiable by visual means. Thus, our office is faced with not only an increase in the number of deaths requiring medico-legal investigation but also an increase in the number of decedents needing additional specialized examinations in an effort to effect identification. This paper attempts to outline the problems and the methods utilized by our office over the past 6 years in the identification process of undocumented border crossers. It is hoped that this paper, as well as the others presented at this symposium, will allow for the sharing of information amongst all medical investigators who assist in the identification of these migrants. The identification of these individuals takes on added importance when one considers the possible nationalities, and perhaps motivation for entering into the US, of those that remain unidentified.     

Skull-photo superimposition and border deaths: identification through exclusion and the failure to exclude

We report on the application of video skull-photo superimposition as an identification method in a case from Ajo, Arizona in which five individuals died after crossing into southern Arizona from Mexico. Initial analyses at the Pima County Forensic Science Center in Tucson, Arizona determined that the disarticulated skeletal remains represented two adult Hispanic males and three adult Hispanic females. Based on biological profiles, both the males and one of the females were tentatively identified and assigned names. The other two females were too similar in age and height, making skeletal separation and identification difficult. As a result, the Michigan State University Forensic Anthropology Laboratory assisted in the identification efforts by performing video skull-photo superimposition on the two unknown females. The skulls were compared to a photograph reported to be one of the missing females. By evaluating facial proportionality and by comparing a number of morphological features of the face and skulls, one skull was excluded as a possible match and one skull was not excluded as a match to the antemortem photo. Because this case was presumed to be a closed disaster, the exclusion of one skull and the failure to exclude the other represented circumstantial identifications.     

Reuniting families: an online database to aid in the identification of undocumented immigrant remains

The Reuniting Families project attempts to aid federal, state and local agencies currently working towards the identification of deceased undocumented immigrants. This initiative has created a distributed on-line database, accessible by public officials and private citizens interested in searching for missing individuals based on both phenotypic and genotypic characteristics. This broad effort includes the exhumation of individuals from geographically disparate pauper graves, the classification of their physical characteristics, and the cataloging of observed metric traits in a local relational database, to include associated articles of possession and related metadata. Concurrent with the documentation of physical forensic evidence is the analysis of mitochondrial DNA sequences. Computational techniques and scoring parameters are applied to automate the process of discovery and identification as well at to preserve information on the missing. The result is a prototype knowledge base that may serve as a model for future efforts in international forensic science collaborations.     

Extent, trends, and perpetrators of prostitution-related homicide in the United States

Prostitute women have the highest homicide victimization rate of any set of women ever studied. We analyzed nine diverse homicide data sets to examine the extent, trends, and perpetrators of prostitution-related homicide in the United States. Most data sources substantially under-ascertained prostitute homicides. As estimated from a conservative capture-recapture analysis, 2.7% of female homicide victims in the United States between 1982 and 2000 were prostitutes. Frequencies of recorded prostitute and client homicides increased substantially in the late 1980s and early 1990s; nearly all of the few observed pimp homicides occurred before the late 1980s. These trends may be linked to the rise of crack cocaine use. Prostitutes were killed primarily by clients, clients were killed mainly by prostitutes, and pimps were killed predominantly by pimps. Another conservative estimate suggests that serial killers accounted for 35% of prostitute homicides. Proactive surveillance of, and evidence collection from, clients and prostitutes might enhance the investigation of prostitution-related homicide.     

Skeletal Indicators of Stress: A Component of the Biocultural Profile of Undocumented Migrants in Southern Arizona,

The ability of forensic anthropologists in the United States to distinguish the remains of foreign nationals from those of American citizens may be crucial to the identification process. This study adds new criteria for identifying Hispanic foreign nationals in southern Arizona to those previously outlined by Birkby et al. (J Forensic Sci 53, 2008, 29) in the “cultural profile.” Skeletal indicators of nonspecific stress were evaluated in undocumented border crossers (UBCs) at the Pima County Office of the Medical Examiner and in documented American samples. Odds ratios show significant associations between UBC status and the presence of porotic hyperostosis and enamel hypoplasias, which are, respectively, 7.9 and 3 times more prevalent among UBCs. These findings are consistent with disparities in access to adequate nutrition and health care during childhood. In conjunction with context and other biocultural factors, the presence of these conditions should prompt practitioners to consider that unidentified remains may represent foreign nationals.     

Fingering a Murderer: A Successful Anthropological and Radiological Collaboration*

Abstract: We illustrate an interdisciplinary approach to identify a victim in a case with complex taphonomic and procedural issues. Burning, fragmentation, species commingling, and examination by multiple experts required anthropological preparation and analysis combined with radiographic adaptations to image and match trabecular patterns in unusually small, burned specimens. A missing person was last seen in the company of a reclusive female on a remote rural property. A warranted search found several burn sites containing human and animal bones. Fragment preparation, analysis, and development of a biological profile by anthropologists enabled examination by the odontologist, molecular biologist, and radiologist, and justified use of antemortem radiographs from one potential victim. Visual and radiological comparison resulted in a positive (later confirmed) identification of the victim by radiological matches of three carpal phalanges. Although some dimensional changes are expected with burning, morphological details were preserved, aided by selection of relatively intact, small bones for comparison.     

Homicide–Suicide in Cuyahoga County,Ohio, 1991–2016

Research on homicides followed by suicides has relied heavily on small samples and relatively short time spans of data. This study helps to fill this gap by examining 26 years of homicide–suicide data from Cuyahoga County, Ohio, between 1991 and 2016. The main data source for the study is medical examiner files. Analyses of the data indicate the rate of homicide–suicide in Cuyahoga County is consistent with other studies but fluctuates considerably across years studied. The majority of victims are female while perpetrators are overwhelmingly male. Black people are overrepresented as victims and offenders. Use of drugs and/or alcohol leading up to the incident is common among perpetrators. Both the homicides and suicides were overwhelming committed with firearms. When comparing our results to the typology of murder–suicides developed by Marzuk, Tardiff, and Hirsch (JAMA 1992;267:3179), we find amorous jealousy is a significant motivating factor in a many cases, including those involving nonintimate partners. Our findings underscore the importance of widespread use of lethality assessment instruments.     

Child abduction murder: the impact of forensic evidence on solvability

This study examined 733 child abduction murders (CAMs) occurring from 1968 to 2002 to explore the influence of forensic evidence on case solvability in CAM investigations. It was hypothesized that the presence of forensic evidence connecting the offender to the crime would enhance case solvability in murder investigations of abducted children. This study examined the impact of CAM of different types of forensic evidence and the impact of the summed total of forensic evidence items on case solvability by controlling for victim age, victim race, victim gender, and victim-offender relationship. Time and distance theoretical predictors were also included. Binomial logistic regression models were used to determine whether forensic evidence was a critical solvability factor in murder investigations of abducted children. This research indicated that, while forensic evidence increased case solvability, the impact of forensic evidence on solvability was not as important as other solvability factors examined.     

Undocumented Border Crosser Deaths in Arizona: Expanding Intrastate Collaborative Efforts in Identification

Undocumented Border Crosser (UBC) deaths in Arizona are a major issue faced by medicolegal authorities. Currently, the Maricopa County Office of the Medical Examiner (MCOME) is in possession of over two hundred unidentified individuals, more than half of whom are presumed to be UBCs. The primary goal of this study was to address the growing number of UBC deaths in Maricopa County in order to provide a more comprehensive picture of this important anthropological issue within the state of Arizona. Of the 107 total UBC cases evaluated for the study, the majority were male and age estimates for all individuals were between 15 to 60 years old. Modeled after the recording system established by the Pima County Office of the Medical Examiner, the biographic and geographic data for these cases were entered into a new UBC database at MCOME and later added to the online Map of Migrant Mortality.     

Comparison of handmarks in manual strangulation: an experimental study

A police case with a strangulated woman with fingermarks on the neck and two suspects identifying each other as the perpetrator set off a laboratory experiment. Twenty-one males participated in the study. Blue paint was applied to their fingers, after which they grasped a neck dummy and pressed hard as if strangulating someone. The imprint was removed from the dummy, and their hands were photographed. Five imprints were randomly chosen and superimposed on the hand photographs in blind trials. In no cases did we match an imprint to the correct hand. However, in four cases we matched the imprint with several hands, one of which was the correct one. This means we were able to exclude nonmatches in 4/5 cases. Overall, matching of hands and fingermarks is difficult and inconclusive. Objective criteria for matching are difficult to establish, and matching is probably best suited for cases with specific anatomical features.     

Human Fatality Due to Thallium Poisoning: Autopsy,Microscopy, and Mass Spectrometry Assays,

Thallium has been responsible for many intoxications since its discovery; however, toxicological profiles for thallium in human fatalities have not been updated recently. Autopsy, microscopic investigations, and toxicological analyses were performed on a married couple who died from thallium sulfate intended homicidal poisoning. The distribution of thallium was established by inductively coupled plasma mass spectrometry with hair samples showing the highest thallium concentration. Electron microscopy revealed a dystrophic condition of hair with disorganized cuticle and atrophy of the hair bulb. Thallium interacts with cells at different levels, with prominent ultrastructural injuries in the mitochondria and endoplasmic reticulum, and high concentration of electron dense granules observed in the cytoplasm and mitochondria of several organs. Alopecia, toxic encephalopathy, and peripheral neuropathy were diagnosed in the victims and suggested to be crucial implications for thallium poisoning. The analytical procedures used in this case are of considerable forensic importance in the diagnosis of thallium poisoning.     

Frequencies of morphological characteristics in two contemporary forensic collections: implications for identification

Positive identification relies on comparison of antemortem and postmortem data. Some identifications are based on morphological features such as fracture, pathological condition, and surgical hardware, despite little literature indicating the frequencies of such traits. This study examines whether such features are sufficiently rare as to be deemed individualizing. Data were collected on two modern North American skeletal collections (N=482 individuals). Presence/absence of features was scored by skeletal element and side. Results indicate that frequencies vary by geographic region (higher frequency of fractures and pathological conditions in New Mexico while individuals in Tennessee were more likely to have surgical interventions), many features such as fractures are remarkably common and that even suites of traits may not be individualizing. Caution is warranted when using written data rather than radiographic comparisons as the primary source of identification. The implications of these findings to missing person databases are also discussed.     

Estimating the timing of long bone fractures: correlation between the postmortem interval, bone moisture content, and blunt force trauma fracture characteristics*

There is very limited knowledge about how long perimortem fracture characteristics persist into the postmortem interval (PMI). Therefore, in this study, 60 porcine long bones were exposed to natural taphonomic conditions and fractured with a steel bone breaking apparatus every 28 days throughout a 141-day period. Differences between macroscopic blunt force trauma fracture characteristics (fracture angle, surface morphology, and outline) were examined to determine if they varied over time or in relationship to bone moisture content (ash weight) and overall assessment. There are significant relationships between (1) PMI and percent ash weight (%AW), fracture surface, and fracture angle and (2) %AW and fracture surface and fracture angle. Bone moisture content correlates significantly with fracture morphology and other characteristics commonly used by forensic anthropologists to determine the timing of traumatic injuries. However, fracture characteristics normally associated with perimortem trauma can persist long into the PMI.     

Toxicology and Circumstances of Death of Homicide Victims in New South Wales, Australia 1996–2005

Abstract:  To determine the prevalence and circumstances of psychoactive substances amongst homicide victims, 485 consecutive cases autopsied at the NSW Department of Forensic Medicine (1/1/1996–12/31/2005) were analyzed. Substances were detected in 62.6% of cases, and illicit drugs in 32.8%. Alcohol, cannabis, opioids, and psychostimulants were most commonly detected. Alcohol and cannabis were both more prevalent amongst males. Mean ages were significantly younger for decedents who tested positive for a substance and for an illicit drug. Cases where death resulted from a physical altercation were more likely to have had alcohol and cannabis present. Illicit drugs were prominent amongst firearms deaths. The proportion of alcohol positive cases increased from 25.0% on Monday to 49.4% for Saturdays/Sundays. Alcohol was more common in incidents in the 0001–0600 h and 1800–2400 h periods. Psychoactive substances appear to substantially increase the risk of homicide, although there are important differences between drug classes in the circumstances of such incidents.     

Strontium and geolocation, the pathway to identification for deceased undocumented mexican border-crossers: a preliminary report

Much of the difficulty associated with identifying and repatriating deceased undocumented border-crossers stems from an inability to narrow down the search area to more probable options. Analysis of the isotopic variation in the tooth enamel of modern Mexican populations is currently underway at the University of California Santa Cruz. Using Thermo Ionization Mass Spectrometry, the pilot research analyzed strontium isotopes located in the donated permanent teeth of Mexican-born individuals of known origin from four states. The preliminary results reveal the formation of three distinctly significant regions in the data set. Using the technology outlined here, a map documenting the isotopic variation in modern Mexican tooth enamel is being complied to use for cross comparison with deceased border crossers of unknown origin.     

Childhood Fatalities in New Mexico: Medical Examiner‐Investigated Cases, 2000–2010

To better understand risk factors and populations at risk of childhood fatalities, a review of all records of childhood deaths (≤19 years) between 2000 and 2010 from New Mexico's statewide medical examiner was conducted. Annually, 313–383 childhood deaths were investigated (3820 total). Males and American Indians were overrepresented (62% and 20.4% of deaths, respectively). The most common manner of death was natural (44.8%), followed by accidental (31.4%), homicide (8.8%), suicide (8.8%), and undetermined (4.1%). Infants under 1 year of age accounted for 41.4% of deaths. Motor vehicle crashes were responsible for the majority of accidental deaths (69%), followed by unintentional overdoses (6.9%), and drowning (5.3%). Gunshot wounds, either intentional or unintentional, caused 10.7% of childhood deaths. Complete medico‐legal investigation of childhood fatalities is needed to provide public health agencies with adequate data to evaluate and prevent childhood deaths.     

An Investigation of Red Fox (Vulpes vulpes) and Eurasian Badger (Meles meles) Scavenging,Scattering, and Removal of Deer Remains: Forensic Implications and Applications

Within northwest Europe, especially the United Kingdom, the red fox (Vulpes vulpes) and the Eurasian Badger (Meles meles) are the largest wild scavengers capable of modifying a set of remains through scavenging. Knowledge of region-specific and species-typical scavenging behaviors of scavengers within the crime scene area and surroundings can aid in more efficient and accurate interpretations. The scavenging behaviors of captive and wild foxes and badgers were recorded and compared through actualistic methods and direct observation. The scavenging by wild foxes and badgers of surface-deposited baits and whole deer (Cervus nippon; Capreolus capreolus) in a woodland was observed and analyzed. Wild foxes were found to scavenge deer more frequently than badgers. The scavenging of deer remains by foxes was also compared with forensic cases. The scavenging pattern and recovery distances of deer and human remains scavenged by foxes were similar but were potentially affected by the condition and deposition of a body, and the presence of clothing.