Forensic Anthropology Notes PDF

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Instructor: Naji Hussain
This document contains notes from chapters in textbook that instructor specified would be covered (ch1-10)...

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CHAPTER 1: INTRODUCTION Forensic anthropology is the study that deals w/ the analysis of human skeletal remains resulting from unexplained deaths. ● Goal of extracting as much info as possible about persons represented by skeletal remains and circumstances surrounding their death ● Analyze legal problems ● Intersects w/ both anthropology and forensic sciences Forensic anthropologists attempt to accomplish 5 main objectives in their work: 1. Determine ancestry 2. Cause and manner of death when it comes to traumatic injury 3. The amount of time that passed since person died (postmortem interval) 4. Assist in locating and recovering buried or surface remains 5. Can provide information useful in obtaining positive ID of the deceased Medicolegal community - medical investigators, coroners ● 50 years is the appropriate period for investigating deaths bc people surrounding the decedents (deceased) and know the circumstances of their deaths, might still be alive ● Traditionally, work with cases of human deaths when soft tissue has degenerated to the point that other medical forensic specialists can’t determine demographics, time since death, and cause + manner of death Historical Background ● Thomas Dwight is known as the “father of forensic anthropology in the U.S.” who was the first to write & give lectures about human skeletal identification ○ His essays discussed methods to determine the age, height and sex of decedents ○ Papers were the first to be applied to forensic situations in the U.S. ● Formative Period (1800s to 1930s) ○ Wilder and Wentworth outlined aspects of human ID from his work on dermatoglyphics (configuration of fingerprints) ● Consolidation period (1939 to 1971) ○ During WWII, the bodies of killed service men couldn’t be recovered fast enough or were so disfigured that ID was difficult ○ Korean War also faced this problem ○ Both events allowed US Army to research on the human remains ● Modern Period (1972 to Present) ○ Physical Anthropology Section in the American Academy of Forensic Sciences (AAFS) ○ American Board of Forensic Anthropology (ABFA) ○ Now, there is a computer database that of information on modern skeletons to collect observations and measurements on documented forensic cases so that new standards of determining demographic and other characteristics can be

updated continuously (FORDISC) Forensic anthro. Is one field w/in a group of specialties in the medicolegal community that deals w/ human death Main experts are: ● Medical examiners and coroners - who have legal responsibility to certify the deaths w/in their jurisdiction when not in the care of a physician. ○ Coroners (elected officials) have no medical training, while medical examiners do. ● Forensic pathologists - medical doctors that perform autopsies and anything that can uncover the cause and manner of death ● They do their work on “fresh” bodies where there is no visible decay and they are recognizable Once human remains are badly decomposed, skeletonized or heavily burned, other specialists are consulted: ● Forensic anthropology - deal w ID of persons from their skeletons ● Forensic archaeology - use archaeological methods to locate and retrieve human skeletal material ● Forensic odontology - dentists who specialize in ID persons from their dentition (teeth) Data-Gathering Methods - laboratory methods are those used to gather data on the mainly skeletal remains and lesser on the associated items. 1. Anthroposcopic - visual inspection of the human body, sometimes w/ aid of Xrays or handheld lens for ID of qualitative nature 2. Osteometric - measurement of human bone on a quantitative scale using calipers or an osteometric board 3. Chemical - analyzing the chemical makeup of certain structures of the skeleton 4. Histological - study of microstructure of bone and teeth a. Cutting off thin slices and staining them to see under a microscope CHAPTER 2: BASICS OF HUMAN OSTEOLOGY AND ODONTOLOGY Osteology - study of bones of the skeleton Odontology - study of dentition; recognition of baby and permanent teeth + placement in the mouth which can vary according to ancestry Important bc bones contain many indicators of basic demographic characteristics of persons + to gain understanding of what is “normal” in the human skeleton and teeth Anatomical position - position of the body, standing or lying, w arms arranged straight along the side and palms facing forward

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Legs extended straight w feet as if they were standing on the ground

**refer to human osteology packet provided by professor**

CHAPTER 3: ESTABLISHING MEDICOLEGAL SIGNIFICANCE Medicolegal significance - remains that need investigation: people that have died w/in 50 years while not in the care of a physician 3 aspects of medicolegal significance: 1. Must determine if it is osteological or dental in nature 2. If the remains are bone, must be determined if they are human. 3. Determine if they have died w/in the last 50 years. Distinguishing Bones and Teeth from Other Material ● Bones can be distinguished grossly by presence of trabecular bone, vascularity, and osteological landmarks. ● For materials that are difficult to identify, the chemical makeup of a sample is compared with that of the Spectral Library for Identification and Classification Explorer (SLICE) at the FBI lab. ○ This technique involves obtaining microslices and submit it to be scanned by microscopes and xrays. ○ Electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) ○ The makeup is then compared to the entries in the database to determine the calcium to phosphorous ratio ○ End result of the analysis: Diagnostic of Osseous/Dental Remains, Inconsistent w/ Osseous/Dental Remains, and Inconclusive. Distinguishing Human from Non-Human ● Distinguishing human from nonhuman bones is one of the easiest methods for eliminating medicolegal significant finds. ● William Bass claimed that 25-30% of cases brought to forensic anthropologists were nonhuman bones. 3 aspects: ○ ○

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Histology - study of microscopic textures of living tissue ■ Arrangement of Haversian systems, osteons, etc. Maturity - distinguish animals whose mature bones are approximately the same size as subadult humans ■ Subadult human bones will have unfused or missing epiphyses, while those of animals will have fused epiphyses. Architecture (shape) - dissimilarities are generally so distinct it is easy to tell them apart

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However bears and pigs share significant similarities to humans

Histological Differences: ● Maria Hiller and Lynne Bell summarize the qualitative and quantitative difference b/w the cortical bone from (mainly) the ribs and long bones of humans and nonhumans ○ The human bone is characterized by dense Haversian systems while large mammal bone has both Haversian bone and plexiform bone ○ In immature large mammals, plexiform bone can be seen throughout the cortex from periosteal to endosteal surfaces ○ In humans, plexiform bone is found only in fetal remains and pathological bone (bone that appears at site of traumatic injury) ● In humans, the diameter of the Haversian systems ranges from 180 um to 325 um, while the structures of other animals lies below this range ○ Also, the size of Human Haversian canals range from 30 um to 175 um, while other animals are much smaller Maturity Distinctions: ● Nonhuman bones are distinguishable from human infants and children by the level of osteological maturity ● Immaturity in bones of subadults is expressed as nonunion of the epiphyses w/ their diaphyses, which gives them an unfinished appearance. Architectural Differences: ● Main method for distinguishing human from nonhuman bones of equal size. ● All mammals including humans have the same bones, w/ some additions and subtractions ● There is also a large number of animals that may be encountered which makes distinguishing difficult. ● Quadrupedal animals share a similar bone architecture required by their four-footed stance different from that of humans (bipedal) ●

Cranial skeleton: ○ The large braincase w/ small face and absence of prominent snout makes human skull unique in animal kingdom ○ Nonhuman skulls include smaller braincase, and presence of saberlike teeth in felid (feline) and canid (canine) skulls

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Axial skeleton: ○ Virtually bones of the axial skeleton from quadrupeds differ from humans ○ Sheep have longer cervical vertebrae and has two curves, one through the neck (concave) and one between the head and the pelvis (convex) ○ Humans have the lumbar vertebrae (concave) while sheep don’t ○ The sacrum of the sheep is “T” shaped ○ The human ribs are more C-shaped, while the sheep’s are half this curved.

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The sternum is more linear in the sheep, looks more like a dagger than the human’s.

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Appendicular skeleton: ○ The arms and legs in people are analogous to those of the forelimbs and hind limbs of quadrupedal animals. ○ They have the same bones in the structure, just different configurations. ○ Human and sheep scapulae (shoulder) are both triangular in shape, however, the widest section is located farthest from the glenoid fossa (sheep) ○ Looking at the humeri, quadrupedals the greater tubercle is more developed at the proximal end and is S-shaped ○ Human humeri are more linear the same goes for the radii and ulnae ○ Metapodials - the metacarpals and metatarsals of four-footed animals ○ Quadrupedals have longer and narrower shaped os coxae where the individual bones are different to that of a human (wider) ○ In the femora, the greater trochanter projects above the head in quadrupeds, but not in humans. ■ Also the articular surface for the tibia continues higher on the shaft than human’s. ■ Multiple notches at distal ends of tibiae in quadrupedals. ○ Bears and humans metacarpals look very similar, the two can be distinguished on the basis of size. ■ The first digit (index finger) is thicker ■ The distal ends of phalanges in bears are more grooved than humans ○ Premolars in pigs and molar teeth in humans are both rectangular in outline and have low cusps in each corner

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Contemporary vs. Noncontemporary: ○ 4 aspects help to distinguish medicolegal significant remains from those that are not: ■ State of preservation - physical status of bones after loss of soft tissue ■ Body modification - changes to the normal structure of bone and teeth that is preferred or required by society ■ Personal belongings - nonosteological items found in association w/ the remains that help to distinguish contemporary from noncontemporary remains (ex: prehistoric tools, clothing) ■ Conditions of interment - circumstances surrounding bodies found in graves (ex: formal burial, position of body)

State of preservation: ● Color ○ Yellowish-white to yellowish-brown tint due to saturation by body fats and fluids ○ After dehydration, it takes to an ivory color ○ A considerable time is necessary for bones to lose its original hue

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Texture ○ Young bone has the same smooth surface as ivory ○ However, w/ protracted exposure, climatic factors, and soil acids erode the surface, causing a loss of original smoothness ○ Grainy or pitted osteological material means that a considerable amount of time has passed ○ Important to remember than graininess increases with age of human, as well as diseases that can lead to bone loss

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Hydration: ○ Bc of bodily fluids, these substances impart a greasy look and feel when soft tissue is first removed ○ w/ extended exposure to air, this moisture is lost and bone appears dry and porous ○ Hydrated and greasy bones indicate little time has passed since death ○ Groundwater in burial site can contribute to moisture in bones

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Weight: ○ The fats and fluids that are part of makeup give bones a surprising amount of weight ○ Weight decreases as moisture evaporates and decalcification (loss of calcium and other minerals) occurs ○ Groundwater can also distribute minerals to bones which may give it weight ○ Important to consider how the env’t effects the remains

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Condition: ○ Contemporary bones are whole with little fragmentation ○ With time and rough handling, they can be fragmented

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Fragility: ○ Over time and env’t factors, bone can become fragile and friable. ○ Bones can even disintegrate ○ Tough and strong-looking bones are of interest to forensic anthropologists

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Soft Tissue: ○ Large amounts of soft tissue that are emanating the odor of decay indicate a contemporary body of medicolegal significance

Body Modification: ● One of the most common forms of modification found in prehistoric remains is cranial deformation ○ Many indigenous people use cradleboards where infants heads are strapped down for safety.

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○ This loses the normal round contour, flattening the occipital bone Dental modifications including crowns, bridges, gold and silver fillings, indicate a contemporary human. ○ The enamel may also wear away exposing the underlying dentin. Posthetics also indicate contemporary human with advances in surgery

Personal Belongings: ● People bury their dead with stuff. ● If it is pottery, tools and basketry → too old → no medicolegal significance. Conditions of Interment: ● Persons who have died under normal circumstances receive a formal burial that involves careful treatment of the deceased ● Perpetrators burying their murder victims do not want to be in prolonged contact w/ the body -- this is why how the body is buried is important ● Main factors that identify burials of persons who died normally ○ Arrangement ■ Tightly flexed - when bodies are placed in fetal position ○ Direction of face ○ Pretreatment ○ Burial enclosure ■ Perpetrators will hide their activities so the local of burial is important

CHAPTER 4: RECOVERY SCENE METHODS In any field operation involving human remains, four main tasks need to be performed: 1. Location - finding the remains, whether they are from a single individual or multiple people 2. Mapping - placement of remains and associated materials must be mapped in relation to a permanent structure (set as a datum point) 3. Excavation - methods of archaeology 4. Collection - remains must be properly collected and packed so they can be brought to a laboratory for further analysis. Forensic anthropologists aren’t that sought out in crime scenes, a preliminary issue: ● Forensic anthropologists need to work closely with law enforcement to identify the victim as well as determine the cause and manner of death ● More of the body needs to be recovered by forensic scientists in order to be properly identified Methods used by law enforcement when processing a Crime Scene: 1. Secure the area so that outsiders cannot enter and possibly remove evidence or drop containing material

2. All investigators must be careful not to contaminate the scene 3. Investigators must also be cautious of where they step so they don’t break any remains or press any into the ground where they might not be recovered 4. Any evidence of previous human intrusion into the area must not be disturbed until it has been reviewed by the investigating officer Time is another preliminary issue: ● Work should be done slowly to ensure that the remains are recovered completely and accurately ● Because evidence is taken from its original position during its field recovery, part of its value is lost forever ● Best to start the process by developing a plan for searching, and after finding, for mapping and collecting the remains. Safety of investigators is another preliminary issue: ● Protection from pathogens such as HIV should be considered Locating Remains ● A search plan must be developed that is tailored to the unique circumstances of the search area ● Should address several issues: ○ Determining the equipment and personnel that can be obtained w/in time and monetary constraints ■ Magnetometer, ground-penetrating radar (GPR), electrical resistivity kit are used for below-ground operations ■ Cadaver dogs (sensitive to smell of decomposition) ■ Visual assessment (least expensive and easiest to perform) which just involves searching the ground for human remains and associated materials ● After the search, the location must be identified ● Followed by any associated materials with the location (i.e. missing body parts) Searching for Human Remains ● Site survey involves arranging a group of searchers side by side in a line, who then walk an area while scanning the ground for any indication of previous human incursion. ● One of the general indicators in recently deposited remains is increased insect activity, and attendant odor ○ Flies and smell bc of decomposition ○ Bones can be numerous colors when exposed to wind and waterbourne soil ○ condition of interment can be determined by the presence of vegetation (if haphazard the site would be bare, while the surrounding area has grass, etc. ○ Soil compaction ■ The dirt near the edge of the interment may pull away, forming cracks that outline the perimeter of the burial

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As soft tissues decompose and the soil compacts, a depression may form in the center of the slope and curves up the edges of the grave ■ A secondary and smaller depression may form in the primary depression when the abdominal cavity collapses Search must be available during the daylight so smaller objects and osteological elements covered by debris can be visible Generally accepted that bodies will be found in areas of easy access Only when human remains are discovered can the other objects be considered significant

Searching for Associated Materials ● Involves finding missing body segments, clothing, weapons, shell casings, etc. ● Bc the locus of the search is known, the visual inspection involves moving outward from that center until all body parts are discovered ● Search each of the cardinal directions as they go, fanning out as they go ● Any indication of human presence is sought ● Their location should be indicated with a marker as well as different wooden flag posts which indicate biological or material remains Mapping Remains ● Mapping is important bc it establishes the credibility of the forensic worker ● Scattered body parts may indicate carnivore activity ● The relationship b/w body elements and physical items may hold important clues to the cause and manner of death ● When drawing a map, it is best to use inches and feet bc it is most common ● Datum point - first step in the mapping process close to the remains ○ The Universal Transverse Mercator (latitude and longitude) from a GPS could also work ● The datum point’s position on a larger map should be indicated ○ A city map of a town, or a USGS quadrangle which its features are approximately sq area of 7-8 mi per side. ● Next, a grid square is established to provide a framework for mapping relevant findings ○ 10-15 ft square constructed w/ wooden posts connected w/ a string ○ The grid is depicted on a map and the compass direction and distance to the datum point of its nearest corner ● Items must be photographed in place before collection ● Finally, a hand drawn map of the grid square must be made, indicating the location of the remains and associated materials in relation to datum point and grid itself. Grave Excavation ● The grave must be systematically excavated using the methods of archaeology ● Must attach a line level to the grid strongs to ensure they are level, so that both vertical and horizontal locations of items w/in the grave can be determined ● Removal of dirt within, immediately around the burial pit

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Dirt is skimmed with a shovel until human remains are encountered ○ Care must be taken that any evidence visible along the grave wall or dirt w/in the grave itself is not lost ○ 1-2 inch layers at a time w/ metal detector scan at 2-4 inches Once part of the body has been located, its orientation is easily determined When items are encountered, they are uncovered but not removed, until they are fully exposed, mapped, and photographed Process is...